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PERSEUS MINING LIMITED — Capital/Financing Update 2014
Aug 26, 2014
46513_rns_2014-08-26_b01b5f26-ecc8-455a-b7ea-161960434d3d.pdf
Capital/Financing Update
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27 August 2014
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NEWS RELEASE
PERSEUS MINING UPDATES EDIKAN MINERAL RESOURCE
Perseus Mining Limited (ASX/TSX: PRU) wishes to advise that following an infill drilling programme on the Edikan Gold Mine (“EGM”) mining leases in Ghana in the period up to June 2014, and after adjusting key assumptions to reflect actual results to date, Mineral Resource estimates have been updated by independent consultant, RungePincockMinarco in accordance with the JORC Code – 2012 Edition. A Table 1 as required by the JORC Code (2012) for each of the revised Mineral Resource estimates is presented in Attachments 2 to 9 respectively.
A detailed summary of the current Mineral Resource estimate for each of the mineral deposits identified to date on the EGM tenements, calculated using a 0.40 g/t gold cut-off grade, is presented in Attachment 1. The Mineral Resource estimates take into account mining depletion as at 30 April 2014 as relevant.
In summary, the revised global Mineral Resource estimate for the EGM is as follows:
Table 1: EGM Measured and Indicated Mineral Resources
| Weathering Domain |
Measured | Measured | Indicated | Indicated | Measured + Indicated | Measured + Indicated | Measured + Indicated | ||
|---|---|---|---|---|---|---|---|---|---|
| ‘000 Tonnes |
Grade (g/t Au1,) |
Contained Gold (oz) |
‘000 Tonnes |
Grade (g/t Au) |
Contained Gold (oz) |
‘000 Tonnes |
Grade (g/t Au) |
Contained Gold (oz) |
|
| Oxides | 240 | 1.8 | 13,800 | 660 | 1.0 | 20,600 | 900 | 1.2 | 34,300 |
| Transition | 760 | 1.3 | 32,500 | 2,700 | 1.1 | 99,700 | 3,460 | 1.2 | 132,200 |
| Fresh | 74,670 | 1.1 | 2,737,300 | 72,510 | 1.0 | 2,434,000 | 147,170 | 1.1 | 5,171,300 |
| TOTAL | 75,670 | 1.1 | 2,783,600 | 75,860 | 1.0 | 2,554,300 | 151,530 | 1.1 | 5,337,800 |
Notes: 1. Denotes grams per tonne of gold; 2. All stated gold grades and quantities are cut grades and cut ounces respectively.
Table 2: EGM Inferred Mineral Resources
| Weathering Domain |
Inferred | Inferred | |
|---|---|---|---|
| ‘000 Tonnes |
Grade (g/t1Au) |
Contained Gold (oz) |
|
| Oxides | 2,960 | 1.1 | 109,100 |
| Transition | 3,140 | 1.1 | 109,700 |
| Fresh | 68,680 | 1.0 | 2,137,000 |
| TOTAL | 74,770 | 1.0 | 2,355,700 |
Relative to the previous Mineral Resource estimate for EGM published in June 2013, the updated Mineral Resource contains 357,300 fewer ounces of gold in the Measured and Indicated categories and 74,300 fewer ounces in the Inferred category. After adjusting both Mineral Resource estimates to the mining surface as at 30 April 2014, the net decrease in Mineral Resources is 155,500 ounces (2.8%) in the Measured and Indicated category and 73,800 ounces (3.0%) in the Inferred category.
Work is underway on revising the design of each of the pits based on the updated Mineral Resources as well as key operating parameters, and reassessing the sequence in which each of the pits will be brought into production, with the objective of maximising cash flow generated by the Edikan operation. The revised Life of Mine Plan and updated Ore Reserve statement is expected to be completed in the December 2014 Quarter.
Perseus Mining Limited Second Floor, 437 Roberts Road, Subiaco WA 6008, Australia PO Box 1578, Subiaco WA 6904, Australia T +618 6144 1700 | F +618 6144 2406
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Comment from Managing Director, Jeff Quartermaine
“ The overall change to Edikan’s Mineral Resource estimate is relatively immaterial but it does reflect several points worth noting.
The first is that actual conditions encountered once mining operations commence do not always totally mirror assumptions made when initial mine planning takes place. In this case the bulk density of ore mined in the AF Gap and Fobinso pits is slightly different to what was assumed in prior Mineral Resource estimates and when this difference is factored into Mineral Resource calculations, it does have an impact, albeit, reasonably small.
The second key takeaway from the current Mineral Resource estimate is that our recent infill drilling programme at Bokitsi South has been successful in identifying mineable material with a head grade well above the life of mine average ore grade that may lead to an increase in the average head grade of ore processed by our mill.
The grade of the Mineral Resources in the Bokitsi North and South deposits has increased from 2.6g/t to 3.0g/t and the amount of contained metal has also increased slightly. Further infill drilling is planned at Bokitsi South that will particularly target extensions to the ore body to the south and at depth where the mineralisation appears to remain open. An infill drilling programme is also currently underway at Mampong with the aim of delineating higher grade material and this will be extended to other deposits at Edikan in due course, subject to budgetary constraints”
To discuss any aspect of this announcement, please contact:
Managing Director: Jeff Quartermaine at telephone +61 8 6144 1700 or email [email protected] (Perth);
Investor Relations: Nathan Ryan at telephone +61 4 20 582 887 or email [email protected] (Melbourne).
Perseus Mining Limited Second Floor, 437 Roberts Road, Subiaco WA 6008, Australia PO Box 1578, Subiaco WA 6904, Australia T +618 6144 1700 | F +618 6144 2406
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Competent Person Statement
The information in this report and the attachments that relates to Mineral Resources for the AFGap-Fobinso and Mampong deposits is based on information compiled by Vanessa O’Toole and Graham de la Mare under the supervision of Steve Hinde, a Competent Person who is a Member of the Australasian Institute of Mining and Metallurgy, and a full time employee of RungePincockMinarco. Mr Hinde has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he has undertaken to qualify as a Competent Person as defined in the JORC Code 2012. Mr Hinde has no economic, financial or pecuniary interest in the company and consents to the inclusion in this report of the matters based on his information in the form and context in which it appears.
The information in this report and the attachments that relates to Mineral Resources for the Bokitsi and Fetish deposits is based on information compiled by Paul Payne under the supervision of Graham de la Mare, a Competent Person who is a Member of the Australian Institute of Geoscientists, and a full time employee of RungePincockMinarco. Mr de la Mare has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he has undertaken to qualify as a Competent Person as defined in the JORC Code 2012.Mr de la Mare has no economic, financial or pecuniary interest in the company and consents to the inclusion in this report of the matters based on his information in the form and context in which it appears.
The information in this report and the attachments that relates to Mineral Resources for the Esuajah North, Esuajah South, and Chirawewa deposits is based on information compiled by Graham de la Mare, a Competent Person who is a Member of the Australian Institute of Geoscientists, and a full time employee of RungePincockMinarco. Mr de la Mare has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he has undertaken to qualify as a Competent Person as defined in the JORC Code 2012.Mr de la Mare has no economic, financial or pecuniary interest in the company and consents to the inclusion in this report of the matters based on his information in the form and context in which it appears.
The information in this report and the attachments that relates to Mineral Resources for the Dadieso deposit is based on information compiled by Vanessa O’Toole under the supervision of Graham de la Mare, a Competent Person who is a Member of the Australian Institute of Geoscientists, and a full time employee of RungePincockMinarco. Mr de la Mare has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he has undertaken to qualify as a Competent Person as defined in the JORC Code 2012.Mr de la Mare has no economic, financial or pecuniary interest in the company and consents to the inclusion in this report of the matters based on his information in the form and context in which it appears.
The information in this report and the attachments that relates to Exploration Results and Sampling for all deposits reported on is based in information compiled by Kevin Thomson, a Competent Person who is a member of the Association of Professional Geoscientists of Ontario and a full time employee of a subsidiary of the Company. Mr Thomson has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he has undertaken to qualify as a Competent Person as defined in the JORC Code 2012 and consents to the inclusion in this report of the matters based on his information in the form and context in which it appears.
Caution Regarding Forward Looking Information : This report contains forward-looking information which is based on the assumptions, estimates, analysis and opinions of management made in light of its experience and its perception of trends, current conditions and expected developments, as well as other factors that management of the Company believes to be relevant and reasonable in the circumstances at the date that such statements are made, but which may prove to be incorrect. Assumptions have been made by the Company regarding, among other things: the price of gold, continuing commercial production at the Edikan Gold Mine without any major disruption, development of a mine at Tengréla, the receipt of required governmental approvals, the accuracy of capital and operating cost estimates, the ability of the Company to operate in a safe, efficient and effective manner and the ability of the Company to obtain financing as and when required and on reasonable terms. Readers are cautioned that the foregoing list is not exhaustive of all factors and assumptions which may have been used by the Company. Although management believes that the assumptions made by the Company and the expectations represented by such information are reasonable, there can be no assurance that the forward-looking information will prove to be accurate. Forward-looking information involves known and unknown risks, uncertainties, and other factors which may cause the actual results, performance or achievements of the Company to be materially different from any anticipated future results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, the actual market price of gold, the actual results of current exploration, the actual results of future exploration, changes in project parameters as plans continue to be evaluated, as well as those factors disclosed in the Company's publicly filed documents. The Company believes that the assumptions and expectations reflected in the forward-looking information are reasonable. Assumptions have been made regarding, among other things, the Company’s ability to
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carry on its exploration and development activities, the timely receipt of required approvals, the price of gold, the ability of the Company to operate in a safe, efficient and effective manner and the ability of the Company to obtain financing as and when required and on reasonable terms. Readers should not place undue reliance on forwardlooking information. Perseus does not undertake to update any forward-looking information, except in accordance with applicable securities laws.
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INDEX OF ATTACHMENTS
1. Edikan Gold Mine Global Mineral Resource Estimate – July 2014
2. JORC Table 1 – AFGap-Fobinso Deposit
3. JORC Table 1 – Fetish Deposit
4. JORC Table 1 – Bokitsi Deposit
5. JORC Table 1 – Chirawewa Deposit
6. JORC Table 1 – Esuajah North Deposit
7. JORC Table 1 – Euajah South Deposit
8. JORC Table 1 – Mampong Deposit
9. JORC Table 1 – Dadieso Deposit
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ATTACHMENT 1
Edikan Gold Mine
Global Mineral Resource Estimate – July 2014
(0.4g/t Au Cut-off Grade)
| Type | Measured | Indicated | Measured & Indicated | Inferred |
|---|---|---|---|---|
| Tonnes Grade Contained g/t Gold(ozs) |
Tonnes Grade Contained g/t Gold(ozs) |
Tonnes Grade Contained g/t Gold(ozs) |
Tonnes Grade Contained g/t Gold(ozs) |
|
| AFGap - Fobinso Deposit | ||||
| Oxide Transition Primary |
0 0.0 0 10,000 0.5 100 35,870,000 1.1 1,277,900 |
180,000 0.6 3,600 60,000 0.6 1,100 24,460,000 0.9 696,700 |
180,000 0.6 3,600 60,000 0.6 1,200 60,330,000 1.0 1,974,700 |
20,000 0.7 500 30,000 0.9 700 28,430,000 0.8 729,600 |
| Total | 35,880,000 1.1 1,278,100 |
24,700,000 0.9 701,400 |
60,570,000 1.0 1,979,400 |
28,480,000 0.8 730,900 |
| Fetish Deposit | ||||
| Oxide Transition Primary |
20,000 1.1 600 190,000 0.9 5,800 12,440,000 0.9 373,200 |
230,000 0.8 6,200 1,000,000 1.0 33,500 16,890,000 1.1 623,700 |
240,000 0.9 6,700 1,190,000 1.0 39,200 29,330,000 1.1 996,900 |
90,000 1.1 3,100 170,000 1.7 9,400 9,520,000 1.1 333,100 |
| Total | 12,650,000 0.9 379,500 |
18,110,000 1.1 663,300 |
30,760,000 1.1 1,042,800 |
9,780,000 1.1 345,600 |
| Bokitsi Deposit | ||||
| Oxide Transition Primary |
30,000 3.6 3,300 50,000 3.5 5,700 640,000 3.7 77,300 |
130,000 1.6 6,600 170,000 2.4 13,100 1,290,000 2.7 112,900 |
160,000 2.0 9,900 220,000 2.7 18,800 1,930,000 3.1 190,200 |
240,000 1.1 8,300 460,000 1.2 18,300 2,190,000 2.0 143,000 |
| Total | 720,000 3.7 86,300 |
1,580,000 2.6 132,500 |
2,310,000 3.0 218,900 |
2,890,000 1.8 169,600 |
| Chirawewa Deposit | ||||
| Oxide Transition Primary |
0 0.0 0 0 0.0 0 0 0.0 0 |
40,000 1.1 1,400 1,200,000 1.1 42,800 4,530,000 1.0 150,500 |
40,000 1.1 1,400 1,200,000 1.1 42,800 4,530,000 1.0 150,500 |
20,000 0.5 400 630,000 0.8 16,600 9,710,000 0.9 266,800 |
| Total | 0 0.0 0 |
5,770,000 1.0 194,700 |
5,770,000 1.0 194,700 |
10,360,000 0.9 283,800 |
| Esuajah North Deposit | ||||
| Oxide Transition Primary |
110,000 1.2 4,400 400,000 1.0 12,500 16,410,000 0.9 476,800 |
60,000 0.8 1,500 240,000 0.9 6,500 18,070,000 0.8 484,500 |
170,000 1.1 5,900 640,000 0.9 19,000 34,480,000 0.9 961,300 |
0 0.5 100 10,000 0.6 200 3,630,000 0.9 104,500 |
| Total | 16,930,000 0.9 493,600 |
18,360,000 0.8 492,600 |
35,290,000 0.9 986,200 |
3,640,000 0.9 104,800 |
| Esuajah South Deposit | ||||
| Oxide Transition Primary |
80,000 2.0 5,500 100,000 2.5 8,400 9,300,000 1.8 532,100 |
30,000 1.3 1,300 30,000 2.8 2,800 7,270,000 1.6 365,700 |
120,000 1.8 6,800 130,000 2.6 11,200 16,580,000 1.7 897,800 |
0 0.0 0 0 0.0 0 5,720,000 1.1 211,300 |
| Total | 9,490,000 1.8 546,000 |
7,340,000 1.6 369,800 |
16,830,000 1.7 915,800 |
5,720,000 1.1 211,300 |
| Mampong Deposit | ||||
| Oxide Transition Primary |
0 0.0 0 0 0.0 0 0 0.0 0 |
0 0.0 0 0 0.0 0 0 0.0 0 |
0 0.0 0 0 0.0 0 0 0.0 0 |
1,170,000 0.8 29,300 1,010,000 0.8 26,200 6,450,000 1.0 201,500 |
| Total | 0 0.0 0 |
0 0.0 0 |
0 0.0 0 |
8,630,000 0.9 257,100 |
| Dadieso Deposit | ||||
| Oxide Transition Primary |
0 0.0 0 0 0.0 0 0 0.0 0 |
0 0.0 0 0 0.0 0 0 0.0 0 |
0 0.0 0 0 0.0 0 0 0.0 0 |
1,410,000 1.5 67,400 830,000 1.4 38,300 3,030,000 1.5 147,100 |
| Total | 0 0.0 0 |
0 0.0 0 |
0 0.0 0 |
5,270,000 1.5 252,800 |
| Grand Total | ||||
| Oxide Transition Primary |
240,000 1.8 13,700 760,000 1.3 32,500 74,670,000 1.1 2,737,300 |
660,000 1.0 20,600 2,700,000 1.1 99,700 72,510,000 1.0 2,434,000 |
900,000 1.2 34,300 3,460,000 1.2 132,200 147,170,000 1.1 5,171,300 |
2,960,000 1.1 109,100 3,140,000 1.1 109,700 68,680,000 1.0 2,137,000 |
| Total | 75,670,000 1.1 2,783,600 |
75,860,000 1.0 2,554,300 |
151,530,000 1.1 5,337,800 |
74,770,000 1.0 2,355,700 |
| Note: All grades and ounces shown are cut grades and ounces |
Note: All grades and ounces shown are cut grades and ounces
Totals may differ due to rounding errors
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ATTACHMENT 2
AFGAP FOBINSO Deposit
JORC Code (2012) Table 1
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Section 1 Sampling Techniques and Data
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Sampling techniques |
Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. |
Drill holes included in the Mineral Resource were sampled using close spaced Grade Control (GC) drilling on a nominal 8m to 10m grid, and Reverse Circulation (RC), and diamond drill (DD) holes on a nominal 20m by 40m grid spacing. A total of 4,890 holes were included in the resource for a total 134,341m within the resource wireframes. Holes were generally angled at 60° towards grid south to optimally intersect the mineralised zones. Grade control holes were drilled vertically. Drill hole collars were picked up and down hole surveyed by qualified surveyors. RC samples were collected by a riffle splitter at 1m intervals. Diamond core was cut in half using a core saw with sampling at 1m intervals, locally to geological boundaries. All samples were collected from the same side of the core. Sampling and QAQC procedures were carried out to industry standards. Approximately 6% of all RC samples were sent to ALS Minerals at Kumasi/Ghana for 24hr bottle roll with AAS finish. All other RC samples were analysed by 50g Fire Assay and AAS finish. Diamond half core samples were sent to Intertek Laboratories (Gh) Ltd at Tarkwa/Ghana for 50gFire Assayand AAS finish. |
| Drilling techniques |
Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face- sampling bit or other type, whether core is oriented and if so, by what method, etc). |
RC drilling comprising 105mm diameter face sampling bit. Diamond drilling carried out with HQ2 and NQ2 sized equipment. |
| Drill sample recovery |
Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. |
Recoveries from historical drilling are unknown. Actual recoveries from PRU diamond drilling recorded in the database and averaged 95.5% with no significant issues noted. RC samples were visually checked for recovery, moisture and contamination. No relationship exists between sample recovery and grade. |
| Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. The total length and percentage of the relevant intersections logged. |
All holes were field logged by company geologists. Weathering, lithology, alteration, structure, mineralogy and veining information were recorded. RC chips are glued to boards as a visual reference of every hole. Logging of diamond core additionally recorded recovery, core strength, orientation, roughness, and infill type. Diamond core was photographed. All drill holes were logged in full. Logging was qualitative and quantitative in nature. |
| Sub-sampling techniques and sample preparation |
If core, whether cut or sawn and whether quarter, half or all core taken. If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. |
HQ2 and NQ2 core was cut in half using a core saw. All samples were collected from the same side of the core. RC samples were collected at the rig using riffle splitters. Samples were predominantly dry. 1% of samples were recorded as wet in the supplied database in the ‘sampquality’ field and were |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub- sampling stages to maximise representivity of samples. Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Whether sample sizes are appropriate to the grain size of the material being sampled. |
removed from the resource composites. Sampling of diamond core and RC chips uses industry standard techniques. After drying the sample is subject to a primary crush, then pulverised so that 90% passes a -75um sieve. Field QC procedures involved the use of certified reference materials (1 in 20), and field duplicates (1 in 20). Field duplicates were taken on 1m composites for RC using a riffle splitter. Sample sizes are considered appropriate to correctly represent the moderately nuggetty gold mineralisation based on: the style of mineralisation, the thickness and consistency of the intersections, the sampling methodology and assay value ranges for Au. |
|
| Quality of assay data and laboratory tests |
The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. |
The analytical techniques used Fire Assay on 50g samples or BLEG bottle roll on 1kg samples both with AAS finish. This method approaches total dissolution of most minerals. No geophysical tools were used to determine any element concentrations used in this resource estimate. Sample preparation checks for fineness were carried out by the laboratory as part of internal procedures to ensure the grind size of 90% passing 75µm was being attained. Laboratory QAQC includes the use of internal standards using certified reference material, and pulp replicates. Certified reference materials demonstrate that sample assay values are accurate. The QAQC results confirm the suitability of the drilling data for use in the Mineral Resource estimation. |
| Verification of sampling and assaying |
The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. |
The PRU logging process involves placing RC drill samples for each 1m interval onto a board to form a visual log of the entire hole. PRU senior exploration personnel verified the significant intersections by comparing the returned assay results to the photographs of the ‘chip boards’. RPM has not independently verified significant intersections of mineralisation. A total of 4 RC holes have been twinned by DD to test down hole contamination in wet intervals. Primary data is entered on hard copies in the field, then entered digitally using LogChiefSoftware (Maxwell GeoServices). This data is directly imported into the central Datashed database (Maxwell GeoServices). Assay values that were below detection limit were adjusted to equal half of the detection limit value. Intervals with no samples were left |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Discuss any adjustment to assay data. |
blank in the database (updated from the -9 value used by PRU). |
|
| Location of data points |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. |
Prior to 2012, a local grid, including baseline, was established at Edikan by Cluff Plc using qualified surveyors. Qualified surveyors were used to locate all drill collars in local grid co- ordinates. PRU drill holes are surveyed down hole at 10m to 30m intervals using either Reflex or Flexit multi-shot equipment. Historical RC holes have not been down hole surveyed and are assumed to be straight. Historical diamond holes were down hole surveyed using either acid tubes or a single shot camera. For recent drill programs, collars have been located in UTM, WGS84, Zone 30N co-ordinates and transformed to local grid. True azimuths were converted to local by subtracting 43 from the true value. Local RL elevations were adjusted by adding 1,000m to avoid negative values. This was not done for the previous Mineral Resource estimates. Topographic surface is based on survey points of the current pit surveyed during mining, and merged with the regional 2010 topographic surface. The quality of the surface immediately above the mineralised lodes has been surveyed with a high degree of confidence by Mine Surveyors. |
| Data spacing and distribution |
Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied. |
The nominal resource drill hole spacing is 20m by 20m. Grade control holes are spaced at 8m by 8m or at 10m by 10m. The mineralised domains have demonstrated sufficient continuity in both geological and grade continuity to support the definition of Mineral Resource, and the classifications applied under the 2012 JORC Code. Samples have been composited to 2m lengths using best fit techniques. Residual sample lengths were excluded. |
| Orientation of data in relation to geological structure |
Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. |
Drill holes are angled to grid north or south, which is approximately perpendicular to the orientation of the mineralised trends. No orientation based sampling bias has been identified in the data. |
| Sample security | The measures taken to ensure sample security. |
Chain of custody is managed by PRU. Samples are stored on site and collected by Intertek and ALS employees. PRU employees have no further involvement in the preparation or analysis of the samples. |
| Audits or |
The results of any audits or reviews of sampling |
A review of sampling techniques was carried out |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| reviews | techniques and data. | on each site visit by RPM, the most recent in 2010. |
Section 2 Reporting of Exploration Results
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Mineral tenement and land tenure status |
Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The security of the tenure held at the time of reporting along with any known impediments to obtaining a license to operate in the area. |
The deposit is located within the Nanankaw Mining Lease ML1110/1994 which is wholly owned by PRU. The tenements are in good standing. |
| Exploration done by other parties |
Acknowledgment and appraisal of exploration by other parties. |
Previous companies to have held the ground include Cluff Mining and Ashanti Goldfields. Exploration activities included RC and Diamond drilling. |
| Geology | Deposit type, geological setting and style of mineralisation. |
The Edikan deposits occur near the western flank of the Ashanti Greenstone Belt along the Obuasi-Akropong gold corridor. The Central Ashanti property is underlain principally by Paleoproterozoic Birimian metasediments of the Kumasi-Afema basin, positioned between the Ashanti and Sefwi Greenstone Belts. The flysch type metasediments consist of dacitic volcaniclastics, greywackes plus argillaceous (phyllitic) sediments, intensely folded, faulted and metamorphosed to upper greenschist facies. Minor cherty and manganiferous exhalative sediments are locally present, and graphitic schists coincide with the principal shear (thrust) zones. Numerous small Basin-type or Cape Coast-type granitoids have intruded the sediments along several regional structures. Gold mineralisation has been identified in a single granitoid intrusive over a strike of 2km between Abnabna and Fobinso. Most of the gold mineralisation is contained within 5 zones which range from 30m to 140m in width and have a moderate to steep northerly plunge. Mineralisation is associated with minor quartz veining and sulphides, which are predominantly pyrite. Associated host sediment Au mineralisation occurs along the margins of the granite. |
| Drill hole information |
A summary of all information material to the under-standing of the exploration results including a tabulation of the following information for all Material drill holes: easting and northing of the drill hole collar elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar dip and azimuth of the hole |
Drill hole locations are shown on the map within the body of this Mineral Resource report. Significant drill hole intersections have been previously reported to the ASX. In the opinion of PRU all material drill results have been adequately reported. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| down hole length and interception depth hole length If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. |
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| Data aggregation methods |
In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. The assumptions used for any reporting of metal equivalent values should be clearly stated. |
Exploration drill results have been previously reported by PRU. No aggregation of intercepts was carried out. Drilling intervals are predominantly even 1m, or composites of 2m or 4m. Mineralised composites are re-split to 1m for re-assay. Metal equivalent values are not being reported. |
| Relationship between mineralisation widths and intercept lengths |
These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g.’down hole length, true width not known’). |
Drill holes are angled to local grid which is approximately perpendicular to the orientation of the mineralised trend. |
| Diagrams | Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. |
A plan showing AAF drilling is included within this Mineral Resource report. |
| Balanced Reporting |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. |
Drill holes have been accurately located by PRU surveyors using the local grid system. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Other substantive exploration data |
Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. |
Ongoing bulk density determinations have been conducted by PRU using mine grab samples and existing stored drill core. Ongoing grade control drilling is conducted as the deposit is being actively mined. |
| Further work | The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or |
No further exploration drilling is planned at the deposit. Ongoing grade control drilling is conducted to define the mineralised lodes as |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| large- scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. |
the deposit is being mined. Along strike and down dip lode extensions have been highlighted in the body of this Mineral Resource report. |
Section 3 Estimation and Reporting of Mineral Resources
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Database integrity |
Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. Data validation procedures used. |
The data base is systematically audited by PRU geologists. All drill logs are validated digitally by the database geologist once assay results are returned from the laboratory. In 2010, RUL reviewed the logging of several holes and validated the records in the database against the drill core and logging boards. No significant errors were noted. RPM validated the 2013 data against previous data from the 2011 estimate. The dip and depth intervals of down hole surveys for a number of drill holes differed from the 2011 database. PRU instructed RPM to use the 2011 data for those holes as the errors were attributed to converting of the PRU current database to Datashed format. RPM noted that recent supplied grade control information contained duplicate hole_id’s. These have been documented and were sent to PRU. All the affected hole numbers were excluded from the current resource update. RPM alsoperformed data audits in Surpac. |
| Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. |
Site visits have been conducted by David Price (RUL) in January 2007, Paul Payne (RUL) in January 2008, and Aaron Green (RPM) in October 2010. On each occasion, the deposit area, the core logging and sampling facility, and drilling and sampling operations were viewed. Aaron Green inspected the main laboratory used by PRU. Notes and photos were taken. Discussions were held with site personnel regarding drilling and sampling procedures. No major issues were encountered. |
| Geological interpretation |
Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. |
The confidence in the geological interpretation is considered to be good and is based on good quality drilling. The deposit consists of steeply dipping mineralised granite lodes. Infill drilling has supported and refined the model and the current interpretation is considered robust. Outcropping of mineralisation and host rocks within the open pit currently being mined confirm the geometry of the mineralisation. Infill drilling has confirmed geological and grade continuity. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Dimensions | The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. |
The AAF resource area extends over a strike length of 2,000m (from 25,750mE – 27,750mE), has an outcropping (within the existing pit) average width of 100m (13,680mN – 13,780mN) and includes the 600m vertical interval from 1,150mRL to 550mRL. |
| Estimation and modelling techniques |
The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. The assumptions made regarding recovery of by- products. Estimation of deleterious elements or other non- grade variables of economic significance (eg sulphur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation |
Using parameters derived from modelled variograms, Ordinary Kriging (OK) was used to estimate average block grades within all domains. Surpac software was used for the estimations. Top-cuts ranging between 10g/t to 30g/t were applied to selected domains and based on statistical analysis. A total of 86 samples were cut. The parent block dimensions used were 10m NS by 10m EW by 10m vertical with sub-cells of 2.5m by 2.5m by 2.5m. The parent block size was selected on the basis of being approximately 50% of the average drill hole spacing in the deposit. RPM has completed numerous Mineral Resource estimates for the deposit since 2009. Each successive update was based on the previous estimate. Mine reconciliation figures show that reconciliation is +8% for the AAF project to date. No assumptions have been made regarding recovery of by-products. No estimation of deleterious elements was carried out. Only Au was interpolated into the block model. An orientated ‘ellipsoid’ search was used to select data and was based on parameters taken from the variography or the observed lode geometry. Three passes were used for each domain. The first pass used a range of 30m, with a minimum of 10 samples. For the second pass, the range was extended to 60m, with a minimum of 6 samples. For the final pass, the range was extended to 250m, with a minimum of 2 samples. A maximum of 40 samples was used for all 3 passes with a maximum of 6 samples per drill hole. Selective mining units were not modelled in the Mineral Resource model. The block size used in the model was based on drill sample spacing and lode orientation. Only Au assay data was available, therefore correlation analysis was not possible. The deposit mineralisation was constrained by wireframes constructed using a 0.2g/t Au cut-off grade in association with logged lithology codes. The wireframes were applied as hard boundaries in the estimate. Statistical analysis was carried out on data from 28 lodes. The high coefficient of variation and the scattering of high grade values observed on the histogram for some of the lodes suggested that high grade cuts were required if linear grade interpolation was to be carried out. As a result highgrade cuts rangingbetween 10g/t to 30g/t |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| was used to control the resource estimates. Discussion of basis for using or not using grade cutting or capping. The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. |
were applied to selected domains, resulting in a total of 86 samples being cut. A three step process was used to validate the model. A qualitative assessment was completed by slicing sections through the block model in positions coincident with drilling. A quantitative assessment of the estimate was completed by comparing the average Au grades of the composite file input against the Au block model output for all the resource objects. A trend analysis was completed by comparing the interpolated blocks to the sample composite data within the granite domain. This analysis was completed for 20m eastings and 10m bench heights. Validation plots showed good correlation between the composite grades and the block model grades. |
|
| Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. |
Tonnages and grades were estimated on a dry in situ basis. No moisture values were reviewed. |
| Cut-off parameters |
The basis of the adopted cut-off grade(s) or quality parameters applied. |
The Mineral Resource has been reported at a 0.4g/t Au cut-off based on assumptions about economic cut-off grades for open pit mining. PRU are currentlyminingthe AAF deposit. |
| Mining factors or assumptions |
Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. |
The AAF deposit is currently being mined using open pit techniques. |
| Metallurgical factors or assumptions |
The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. |
Extensive metallurgical test-work was completed on material from a number of deposits within Edikan Project area, by AMMTEC Pty Ltd in Perth for Cluff Plc in the early 1990’s. This focused on CIL test-work on both oxide and sulphide material and later to heap leach. Preliminary amalgamation and cyanidation results using bottle roll methodology confirmed the free milling nature of both the oxide and granite mineralisation. Metallurgical test-work was undertaken by PRU in 2011 aspart of the DFS. |
| Environmental factors or assumptions |
Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonableprospectsfor eventual economic |
The Project is not subject to any environmental liabilities except for a progressive decommissioning and reclamation plan for the closed Ayanfuri heapleach mine. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. |
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| Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. |
Bulk density values were originally determined at AAF from direct measurement of 738 diamond core samples of which 360 were conducted in-house by PRU and 378 completed by commercial laboratories. A recent study by PRU determined that the current density assigned to fresh granite was likely too high. This assumption was based on a better understanding of the granite lodes from open pit mining activities which suggested the material should be less dense than originally expected. A program of submitting existing drill core for analysis was instigated in early 2014. A total of 254 grab samples from the open pit and 261 core samples were sent to commercial laboratories for analysis. A total of 130 core samples were sent to Intertek, and 131 core samples and all the grab samples sent to ALS. Results suggested the fresh granite material had a density in the order of 2.7t/m3 and this has been assigned to this material type in the current RPM block model. Measurements were determined by wax coating samples and immersing in water. RPM recommends an ongoing program of submitting grab samples to Intertek for analysis. Suitable core samples from any future diamond drilling programs should be selectively sent for analysis. |
| Classification | The basis for the classification of the Mineral Resources into varying confidence categories. |
The Mineral Resource was classified as Measured, Indicated and Inferred Mineral Resource. The Measured portion of the resource was defined where the drill spacing was predominantly at 20m by 20m, and continuity of mineralisation was robust. The portion of the deposit where the drill spacing was generally greater than 20m by 20m but still demonstrates good lode and grade continuity was classified as Indicated Mineral Resource. The portions of the deposit classified as Inferred include poorly tested areas of the main zones, small zones peripheral to the main structures which are defined by four or less intersections with no clear lateral continuity, and zones of increased complexity which require more detailed information. The input data is comprehensive in its coverage of the mineralisation and does not favour or misrepresent in-situ mineralisation. The definition of mineralised zones is based on high levelgeological understanding producinga |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). Whether the result appropriately reflects the Competent Person’s view of the deposit. |
robust model of mineralised domains. This model has been confirmed by infill drilling and mining which supported the interpretation. Validation of the block model shows good correlation of the input data to the estimated grades. The Mineral Resource estimate appropriately reflects the view of the Competent Person. |
|
| Audits or reviews |
The results of any audits or reviews of Mineral Resource estimates. |
Internal audits have been completed by RPM which verified the technical inputs, methodology, parameters and results of the estimate. |
| Discussion of relative accuracy/ confidence |
Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. |
The AAF Mineral Resource estimate has been reported with a high degree of confidence. The lode geometry and continuity has been robustly interpreted to reflect the applied level of Measured and Indicated Mineral Resource. The data quality is good and the drill holes have detailed logs produced by qualified geologists. A recognised laboratory has been used for all analyses. The Mineral Resource statement relates to global estimates of tonnes and grade. The deposit is currently being mined using open pit techniques. Mine reconciliation to date shows 8% more tonnes mined when compared to the Mineral Resource model. |
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ATTACHMENT 3
Fetish Deposit
JORC Code (2012) Table 1
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Section 1 Sampling Techniques and Data
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Sampling techniques |
Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. |
Samples at Fetish were collected using drilling techniques such as Reverse Circulation (RC) and Diamond Drilling (DD). Holes were generally angled at between 45° and 60° towards grid west or east to optimally intersect the mineralised zones. Some RC drill holes have diamond tails. RC samples were collected as 4m composites until potential mineralisation was expected at which time samples were collected at 1m intervals from a rig mounted cyclone into large numbered plastic bags. Recently, PRU drilling has used 2m composite samples, and then 1m samples through potential mineralisation. Diamond core was generally sampled at even 1m intervals. Sampling and QAQC procedures were carried out to industry standards. Rig mounted riffle splitters were used to split RC samples and minimise bias. Diamond core was cut in half using a diamond saw and the right hand side of the core was always submitted for analysis with the left side being stored in trays on site. Approximately 5% of all RC samples were sent to the Intertek (formerly TWL) laboratory for 24hr bottle roll with AAS finish. All other RC samples and Diamond half core were analysed by 50g Fire Assay and AAS finish. Samples were sent to Intertek Laboratories (Gh) Ltd at Tarkwa/Ghana (24%), ALS (35%), TWL (18%), and SGS laboratories(2%). |
| Drilling techniques |
Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face- sampling bit or other type, whether core is oriented and if so, by what method, etc). |
RC drilling comprising 105mm diameter face sampling bit. Diamond drilling carried out with HQ2 and NQ2 sized equipment. |
| Drill sample recovery |
Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. |
Recoveries from historical drilling are unknown. Actual recoveries from PRU diamond drilling recorded in the database and averaged 93% with no significant issues noted. RC samples were visually checked for recovery, moisture and contamination. No relationship exists between sample recovery and grade. |
| Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. The total length and percentage of the relevant intersections logged. |
All holes were field logged by company geologists. Weathering, lithology, alteration, structure, mineralogy and veining information were recorded. RC chips are glued to boards as a visual reference of every hole. Logging of diamond core additionally recorded recovery, core strength, orientation, roughness, and infill type. Diamond core was photographed. All drill holes were logged in full. Logging was qualitative and quantitative in nature. |
| Sub-sampling techniques and |
If core, whether cut or sawn and whether quarter, half or all core taken. |
HQ2 and NQ2 core was cut in half using a core saw. All samples were collected from the same side of the core. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| sample preparation |
If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub- sampling stages to maximise representivity of samples. Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Whether sample sizes are appropriate to the grain size of the material being sampled. |
RC samples were collected at the rig using riffle splitters. Samples were predominantly dry. Sampling of diamond core and RC chips uses industry standard techniques. After drying the sample is subject to a primary crush, then pulverised so that 90% passes a -75um sieve. Field QC procedures involved the use of certified reference materials (1 in 20), and field duplicates (1 in 20). Field duplicates were taken on 1m composites for RC using a riffle splitter. Sample sizes are considered appropriate to correctly represent the moderately nuggetty gold mineralisation based on: the style of mineralisation, the thickness and consistency of the intersections, the sampling methodology and assay value ranges for Au. |
| Quality of assay data and laboratory tests |
The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. |
The analytical techniques used Fire Assay on 50g pulp samples with AAS finish. Historically, RC samples were subject to BLEG bottle roll on 1kg samples with AAS finish. This method approaches total dissolution of most minerals. No geophysical tools were used to determine any element concentrations used in this Mineral Resource estimate. Sample preparation checks for fineness were carried out by the laboratory as part of internal procedures to ensure the grind size of 90% passing 75µm was being attained. Laboratory QAQC includes the use of internal standards using certified reference material, and pulp replicates. Certified reference materials demonstrate that sample assay values are accurate. The QAQC results confirm that acceptable levels of accuracy and precision have been established. |
| Verification of sampling and assaying |
The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. |
The PRU logging process involves placing RC drill samples for each 1m interval onto a board to form a visual log of the entire hole. PRU senior exploration personnel verified the significant intersections by comparing the returned assay results to the photographs of the ‘chip boards’. Twinned holes have not been drilled. Primary data is entered on hard copies in the field, then entered digitally using LogChiefSoftware (Maxwell GeoServices). This data is directly imported into the central Datashed database (Maxwell GeoServices). Assay values that were below detection limit were adjusted to equal half of the detection limit value. Intervals with no samples were left blank in the database (updated from the -9 value used by PRU). |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Discuss any adjustment to assay data. |
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| Location of data points |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. |
Prior to 2012, a local grid, including baseline, was established at Edikan by Cluff Plc using qualified surveyors. PRU surveyors have since been used to locate all drill collars in local grid co-ordinates. The majority of PRU drill holes are surveyed down hole at 10m to 30m intervals using either Reflex or Flexit multi-shot equipment. Historical RC holes have not been down hole surveyed and are assumed to be straight. Historical diamond holes were down hole surveyed using either acid tubes or a single shot camera at 60m intervals and at the end of the hole. For recent drill programs, collars have been located in UTM, WGS84, Zone 30N co-ordinates and transformed to local grid. True azimuths were converted to local by subtracting 43 from the true value. Local RL elevations were adjusted by adding 1,000m to avoid negative values. This was not done for the initial Mineral Resource estimates. Topographic surface is based on survey points of the existing open pits and drill collars, and merged with the regional topographic surface. The quality of the surface immediately above the mineralised lodes has been surveyed with a high degree of confidence. |
| Data spacing and distribution |
Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied. |
The nominal drill hole spacing is 20m by 20m. The drill hole spacing and distribution is considered sufficient to establish the degree of continuity appropriate for the Mineral Resource estimation procedures. Samples were composited to 4m in zones previously identified as barren, otherwise composites at 2m intervals with 1m sampling intervals through expected mineralised zones. |
| Orientation of data in relation to geological structure |
Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. |
Drill holes are angled to grid west or east, which is approximately perpendicular to the orientation of the mineralised trends. Due to the orientation of drill holes to the east or west, several holes have been drilled down dip within an east dipping sediment lode. Adjacent drill holes orientated to the west have shown that sampling bias from those two holes is not a significant issue. |
| Sample security | The measures taken to ensure sample security. |
Chain of custody is managed by PRU. Samples are stored on site and collected by laboratory employees. PRU employees have no further involvement in the preparation or analysis of the samples. |
| Audits or reviews |
The results of any audits or reviews of sampling techniques and data. |
A review of sampling techniques was carried out on each site visit by RPM, the most recent in 2010. |
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Section 2 Reporting of Exploration Results
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Mineral tenement and land tenure status |
Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The security of the tenure held at the time of reporting along with any known impediments to obtaining a license to operate in the area. |
The deposit is located within the Nanankaw Mining Lease ML1110/1994 which is wholly owned by PRU. The Mining Lease was granted for a term of 15 years and expires 30 December 2024 The tenements are in good standing. |
| Exploration done by other parties |
Acknowledgment and appraisal of exploration by other parties. |
Previous companies to have held the ground include Cluff Mining and Ashanti Goldfields. Exploration activities included RC and Diamond drilling. |
| Geology | Deposit type, geological setting and style of mineralisation. |
The Edikan deposits occur near the western flank of the Ashanti Greenstone Belt along the Obuasi-Akropong gold corridor. The Central Ashanti property is underlain principally by Paleoproterozoic Birimian metasediments of the Kumasi-Afema basin, positioned between the Ashanti and Sefwi Greenstone Belts. The flysch type metasediments consist of dacitic volcaniclastics, greywackes plus argillaceous (phyllitic) sediments, intensely folded, faulted and metamorphosed to upper greenschist facies. Minor cherty and manganiferous exhalative sediments are locally present, and graphitic schists coincide with the principal shear (thrust) zones. Numerous small Basin-type or Cape Coast-type granitoids have intruded the sediments along several regional structures. Gold mineralisation has been identified within, or is associated with, the margins of a granitoid intrusive which has intruded into a sequence of metasediments. Mineralisation is typically 40- 170m wide and remains open at depth. Mineralisation is associated with minor quartz veining and sulphides which are predominantly pyrite. |
| Drill hole information |
A summary of all information material to the under-standing of the exploration results including a tabulation of the following information for all Material drill holes: easting and northing of the drill hole collar elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar dip and azimuth of the hole down hole length and interception depth hole length If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. |
Exploration results are not being reported. Drill hole locations are shown on the map within the body of this Mineral Resource report. Significant drill hole intersections have been previously reported to the ASX. In the opinion of PRU all material drill results have been adequately reported. |
| Data | In reporting Exploration Results, weighting |
Exploration drill results are not being reported. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| aggregation methods |
averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. The assumptions used for any reporting of metal equivalent values should be clearly stated. |
No aggregation of intercepts was carried out. Drilling intervals are predominantly even 1m, or composites of 2m or 4m. Mineralised composites are re-split to 1m for re-assay. Metal equivalent values are not being reported. |
| Relationship between mineralisation widths and intercept lengths |
These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g.’down hole length, true width not known’). |
Drill holes are angled to local grid which is approximately perpendicular to the orientation of the mineralised trend. |
| Diagrams | Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. |
A plan showing Fetish drilling is included within this Mineral Resource report. |
| Balanced Reporting |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. |
Drill holes have been accurately located by PRU surveyors using the local grid system. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Other substantive exploration data |
Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. |
Ongoing bulk density determinations have been conducted by PRU using existing stored drill core. |
| Further work | The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large- scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. |
Further work at the deposit will be guided by the results of pit optimisation analysis of the Mineral Resource. Along strike and down dip lode extensions have been highlighted in the body of this Mineral Resource report. |
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Section 3 Estimation and Reporting of Mineral Resources
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Database integrity |
Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. Data validation procedures used. |
The data base is systematically audited by PRU geologists. All drill logs are validated digitally by the database geologist once assay results are returned from the laboratory. In 2010, RUL reviewed the logging of several holes and validated the records in the database against the drill core and logging boards. No significant errors were noted. RPM performed data audits in Surpac. |
| Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. |
Site visits have been conducted by David Price (RUL) in January 2007, Paul Payne (RUL) in January 2008, and Aaron Green (RPM) in October 2010. On each occasion, the deposit area, the core logging and sampling facility, and drilling and sampling operations were viewed. Aaron Green inspected the main laboratory used by PRU. Notes and photos were taken. Discussions were held with site personnel regarding drilling and sampling procedures. No major issues were encountered. |
| Geological interpretation |
Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. |
The confidence in the geological interpretation is considered to be good and is based on good quality drilling. The deposit consists of steeply dipping mineralised granite and sediment lodes which have been interpreted based on logging of samples taken at regular intervals from angled drill holes. |
| Dimensions | The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. |
The Fetish Mineral Resource area extends over a strike length of 550m (from 4,990mN – 5,540mN), has a typical width of 140m. It includes the 595m vertical interval from 1,180mRL to 585mRL. |
| Estimation and modelling techniques |
The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. |
Using parameters derived from modelled variograms, Ordinary Kriging (OK) was used to estimate average block grades within the deposit. Surpac software was used for the estimations. A top-cut of 25g/t was appropriate for granite hosted domains and a top-cut of 10g/t was used for sediment hosted domains. A total of 23 samples were cut. The parent block dimensions used were 10m NS by 5m EW by 10m vertical with sub-cells of 2.5m by 1.25m by 2.5m. The parent block size was selected on the basis of being approximately 50% of the average drill hole spacing in the deposit. Historicalproduction records were available for |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. The assumptions made regarding recovery of by- products. Estimation of deleterious elements or other non- grade variables of economic significance (eg sulphur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation was used to control the resource estimates. Discussion of basis for using or not using grade cutting or capping. |
shallow oxide pits completed in the 1990’s. RPM has completed numerous Mineral Resource estimates for the deposit since 2009. Each successive update was based on the previous estimate and extended with additional drilling data. No assumptions have been made regarding recovery of by-products. No estimation of deleterious elements was carried out. Only Au was interpolated into the block model. An orientated ‘ellipsoid’ search was used to select data and was based on parameters taken from the variography or the observed lode geometry. Three passes were used for each domain. The first pass used a range of 40m, with a minimum of 10 samples. For the second pass, the range was extended to 80m, with a minimum of 6 samples. For the final pass, the range was extended to 200m, with a minimum of 1 sample. A maximum of 40 samples was used for all 3 passes. Selective mining units were not modelled in the Mineral Resource model. The block size used in the model was based on drill sample spacing and lode orientation. Only Au assay data was available, therefore correlation analysis was not possible. The deposit mineralisation was constrained by wireframes constructed using a 0.2g/t Au cut-off grade in association with logged lithology codes. The wireframes were applied as hard boundaries in the estimate. Statistical analysis was carried out on data from 30 lodes. The high coefficient of variation and the scattering of high grade values observed on the histogram for some of the objects suggested that high grade cuts were required if linear grade interpolation was to be carried out. As a result high grade cuts of 25g/t for granite domains, and 10g/t for sediment domains were applied, resulting in a total of 23 samples being cut. A three step process was used to validate the model. A qualitative assessment was completed by slicing sections through the block model in positions coincident with drilling. A quantitative assessment of the estimate was completed by comparing the average Au grades of the composite file input against the Au block model output for all the resource objects. A trend analysis was completed by comparing the interpolated blocks to the sample composite data within the granite domain. This analysis was completed for 20m northings and 20m bench heights. Validation plots showed good correlation between the composite grades and the block model grades. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. |
||
| Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. |
Tonnages and grades were estimated on a dry in situ basis. No moisture values were reviewed. |
| Cut-off parameters |
The basis of the adopted cut-off grade(s) or quality parameters applied. |
The Mineral Resource has been reported at a 0.4g/t Au cut-off based on assumptions about economic cut-off grades for open pit mining. PRU are currently mining the AAF deposit which formspart of the Edikan Mine Project area. |
| Mining factors or assumptions |
Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. |
The AAF deposit is currently being mined using open pit techniques. The Fetish deposit is of similar style to that of the AAF deposit and could be mined using both open pit and underground methods. |
| Metallurgical factors or assumptions |
The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. |
Metallurgical test-work was undertaken by PRU in 2011 as part of the DFS. Mineralisation characteristics of the granite hosted mineralisation at Fetish are similar to the mineralisation being process at the Edikan operation. |
| Environmental factors or assumptions |
Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. |
The Project is not subject to any environmental liabilities except for a progressive decommissioning and reclamation plan for the closed Ayanfuri heap leach mine. |
| Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones |
A recent study by PRU determined that the previous densities assigned to fresh granite and sediment material were probably too high. A program of submitting existing drill core for analysis was instigated in June 2014. A total of 485 existing drill core samples were sent to commercial laboratories for analysis. Results suggested the fresh granite material had a density in the order of 2.7t/m3and that fresh |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. |
sediment had a density of 2.77t/m3. These values were used in the current RPM block model. Measurements were determined by wax coating samples and immersing in water. RPM recommends an ongoing program of submitting suitable core samples for density analysis from any future diamond drilling programs. |
|
| Classification | The basis for the classification of the Mineral Resources into varying confidence categories. Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). Whether the result appropriately reflects the Competent Person’s view of the deposit. |
Mineral Resources were classified in accordance with the Australasian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC, 2012). The Mineral Resource was classified as Measured, Indicated and Inferred Mineral Resource on the basis of data quality, sample spacing, and lode continuity. The Measured portion of the Mineral Resource was defined where the drill spacing was predominantly at 20m by 20m, and continuity of mineralisation was robust. The Indicated portion of the Mineral Resource was defined where the drill spacing was predominantly at 40m by 20m, and continuity of mineralisation was evident. The portions of the deposit classified as Inferred Mineral Resource include sparsely tested depth extensions of the main zones, and small zones peripheral to the main structures which appear to have poor clear lateral continuity or are untested. The input data is comprehensive in its coverage of the mineralisation and does not favour or misrepresent in-situ mineralisation. The definition of mineralised zones is based on high level geological understanding producing a robust model of mineralised domains. This model has been confirmed by infill drilling which supported the interpretation. Validation of the block model shows good correlation of the input data to the estimated grades. The Mineral Resource estimate appropriately reflects the view of the Competent Person. |
| Audits or reviews |
The results of any audits or reviews of Mineral Resource estimates. |
Internal audits have been completed by RPM which verified the technical inputs, methodology, parameters and results of the estimate. |
| Discussion of relative accuracy/ confidence |
Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical |
The Fetish Mineral Resource estimate has been reported with a high degree of confidence. The lode geometry and continuity has been interpreted to reflect the Mineral Resource classification. The data quality is good and the |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. |
drill holes have detailed logs produced by qualified geologists. Recognised laboratories have been used for all analyses. The Mineral Resource statement relates to global estimates of tonnes and grade. The deposit is not currently being mined. Historical production records are available for the deposit. |
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ATTACHMENT 4
Bokitsi Deposit
JORC Code (2012) Table 1
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Section 1 Sampling Techniques and Data
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Sampling techniques |
Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. |
Samples at Bokitsi were collected using drilling techniques such as Reverse Circulation (RC) and Diamond Drilling (DD). Holes were generally angled at between 45° and 60° towards grid west to optimally intersect the mineralised zones. Some RC drill holes have diamond tails. RC samples were collected as 4m composites until potential mineralisation was expected at which time samples were collected at 1m intervals from a rig mounted cyclone into large numbered plastic bags. Recent PRU drilling has used 2m composite samples, and then 1m samples through potential mineralisation. Diamond core was generally sampled at even 1m intervals. Sampling and QAQC procedures were carried out to industry standards. Rig mounted riffle splitters were used to split RC samples and minimise bias. Diamond core was cut in half using a diamond saw and the right hand side of the core was always submitted for analysis with the left side being stored in trays on site. Approximately 5% of all RC samples were sent to the Intertek (formerly TWL) laboratory for 24hr bottle roll with AAS finish. All other RC samples and Diamond half core were analysed by 50g Fire Assay and AAS finish. Samples were sent to Intertek Laboratories (Gh) Ltd at Tarkwa/Ghana (24%), ALS (35%), TWL (18%), and SGS laboratories(2%). |
| Drilling techniques |
Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face- sampling bit or other type, whether core is oriented and if so, by what method, etc). |
RC drilling comprising 105mm diameter face sampling bit. Diamond drilling carried out with HQ2 and NQ2 sized equipment. |
| Drill sample recovery |
Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. |
Recoveries from historical drilling are unknown. Actual recoveries from PRU diamond drilling recorded in the database and averaged 93% with no significant issues noted. RC samples were visually checked for recovery, moisture and contamination. No relationship exists between sample recovery and grade. |
| Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. The total length and percentage of the relevant intersections logged. |
All holes were field logged by company geologists. Weathering, lithology, alteration, structure, mineralogy and veining information were recorded. RC chips are glued to boards as a visual reference of every hole. Logging of diamond core additionally recorded recovery, core strength, orientation, roughness, and infill type. Diamond core was photographed. All drill holes were logged in full. Logging was qualitative and quantitative in nature. |
| Sub-sampling techniques and sample |
If core, whether cut or sawn and whether quarter, half or all core taken. If non-core, whether riffled, tube sampled, rotary |
HQ2 and NQ2 core was cut in half using a core saw. All samples were collected from the same side of the core. RC samples were collected at the rigusingriffle |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| preparation | split, etc and whether sampled wet or dry. For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub- sampling stages to maximise representivity of samples. Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Whether sample sizes are appropriate to the grain size of the material being sampled. |
splitters. Samples were predominantly dry. Sampling of diamond core and RC chips uses industry standard techniques. After drying the sample is subject to a primary crush, then pulverised so that 90% passes a -75um sieve. Field QC procedures involved the use of certified reference materials (1 in 20), and field duplicates (1 in 20). Field duplicates were taken on 1m composites for RC using a riffle splitter. Sample sizes are considered appropriate to correctly represent the moderately nuggetty gold mineralisation based on: the style of mineralisation, the thickness and consistency of the intersections, the sampling methodology and assay value ranges for Au. |
| Quality of assay data and laboratory tests |
The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. |
The analytical techniques used Fire Assay on 50g pulp samples with AAS finish. Historically, RC samples were subject to BLEG bottle roll on 1kg samples with AAS finish. This method approaches total dissolution of most minerals. No geophysical tools were used to determine any element concentrations used in this Mineral Resource estimate. Sample preparation checks for fineness were carried out by the laboratory as part of internal procedures to ensure the grind size of 90% passing 75µm was being attained. Laboratory QAQC includes the use of internal standards using certified reference material, and pulp replicates. Certified reference materials demonstrate that sample assay values are accurate. The QAQC results confirm that acceptable levels of accuracy and precision have been established. |
| Verification of sampling and assaying |
The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. Discuss any adjustment to assay data. |
The PRU logging process involves placing RC drill samples for each 1m interval onto a board to form a visual log of the entire hole. PRU senior exploration personnel verified the significant intersections by comparing the returned assay results to the photographs of the ‘chip boards’. Twinned holes have not been drilled. Primary data is entered on hard copies in the field, then entered digitally using LogChiefSoftware (Maxwell GeoServices). This data is directly imported into the central Datashed database (Maxwell GeoServices). Assay values that were below detection limit were adjusted to equal half of the detection limit value. Intervals with no samples were left blank in the database (updated from the -9 value used by PRU). |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Location of data points |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. |
Prior to 2012, a local grid, including baseline, was established at Edikan by Cluff Plc using qualfied surveyors. PRU surveyors have since been used to locate all drill collars in local grid co-ordinates. PRU drill holes are surveyed down hole at 10m to 30m intervals using either Reflex or Flexit multi-shot equipment. Historical RC holes have not been down hole surveyed and are assumed to be straight. For recent drill programs, collars have been located in UTM, WGS84, Zone 30N co-ordinates and transformed to local grid. True azimuths were converted to local by subtracting 43 from the true value. Local RL elevations were adjusted by adding 1,000m to avoid negative values. This was not done for the initial Mineral Resource estimates. Topographic surface is based on survey points of the existing open pits and drill collars, and merged with the regional topographic surface. The quality of the surface immediately above the mineralised lodes has been surveyed with a high degree of confidence. |
| Data spacing and distribution |
Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied. |
The nominal drill hole spacing is 20m by 20m and 40m by 40m. The drill hole spacing and distribution is considered sufficient to establish the degree of continuity appropriate for the Mineral Resource estimation procedures. Samples were composited to 4m intervals through zones previously identified as barren, otherwise 2m composites were collected with 1m sampling intervals through expected mineralised zones. |
| Orientation of data in relation to geological structure |
Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. |
Drill holes are angled to predominantly grid west, which is approximately perpendicular to the orientation of the mineralised trends. Historical AGC holes orientated to grid east. Due to the orientation of drill holes to the east or west, several holes have been drilled down dip within an east dipping sediment lode. Adjacent drill holes orientated to the west have shown that sampling bias from those two holes is not a significant issue. East dipping holes were excluded from the estimate. |
| Sample security | The measures taken to ensure sample security. |
Chain of custody is managed by PRU. Samples are stored on site and collected by laboratory employees. PRU employees have no further involvement in the preparation or analysis of the samples. |
| Audits or reviews |
The results of any audits or reviews of sampling techniques and data. |
A review of sampling techniques was carried out on each site visit by RPM, the most recent in 2010. |
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Section 2 Reporting of Exploration Results
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Mineral tenement and land tenure status |
Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The security of the tenure held at the time of reporting along with any known impediments to obtaining a license to operate in the area. |
The deposit is located within the Nanankaw Mining Lease ML1110/1994 which is wholly owned by PRU. The Mining Lease was granted for a term of 15 years and expires 30 December 2024 The tenements are in good standing. |
| Exploration done by other parties |
Acknowledgment and appraisal of exploration by other parties. |
Previous companies to have held the ground include Cluff Mining and Ashanti Goldfields. Exploration activities included RC and Diamond drilling. |
| Geology | Deposit type, geological setting and style of mineralisation. |
The Edikan deposits occur near the western flank of the Ashanti Greenstone Belt along the Obuasi-Akropong gold corridor. The Central Ashanti property is underlain principally by Paleoproterozoic Birimian metasediments of the Kumasi-Afema basin, positioned between the Ashanti and Sefwi Greenstone Belts. The flysch type metasediments consist of dacitic volcaniclastics, greywackes plus argillaceous (phyllitic) sediments, intensely folded, faulted and metamorphosed to upper greenschist facies. Minor cherty and manganiferous exhalative sediments are locally present, and graphitic schists coincide with the principal shear (thrust) zones. Numerous small Basin-type or Cape Coast-type granitoids have intruded the sediments along several regional structures. Mineralisation at Bokitsi is concentrated and confined mainly within steeply dipping units hosted within sediments and schists. The mineralisation style differs from the majority of the other Perseus deposits, which are predominantly hosted within granites.. Mineralisation is associated with minor quartz veining and sulphides which are predominantly pyrite. |
| Drill hole information |
A summary of all information material to the under-standing of the exploration results including a tabulation of the following information for all Material drill holes: easting and northing of the drill hole collar elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar dip and azimuth of the hole down hole length and interception depth hole length If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. |
Exploration results are not being reported. Drill hole locations are shown on the map within the body of this Mineral Resource report. Significant drill hole intersections have been previously reported to the ASX. In the opinion of PRU all material drill results have been adequately reported. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Data aggregation methods |
In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. The assumptions used for any reporting of metal equivalent values should be clearly stated. |
Exploration drill results are not being reported. No aggregation of intercepts was carried out. Drilling intervals are predominantly even 1m, or composites of 2m or 4m. Mineralised composites are re-split to 1m for re-assay. Metal equivalent values are not being reported. |
| Relationship between mineralisation widths and intercept lengths |
These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g.’down hole length, true width not known’). |
Drill holes are angled to local grid which is approximately perpendicular to the orientation of the mineralised trend. |
| Diagrams | Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. |
A plan showing Bokitsi drilling is included within this Mineral Resource report. |
| Balanced Reporting |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. |
Drill holes have been accurately located by PRU surveyors using the local grid system. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Other substantive exploration data |
Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. |
Ongoing bulk density determinations have been conducted by PRU using existing stored drill core. |
| Further work | The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large- scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. |
Further work at the deposit will be guided by the results of pit optimisation analysis of the Mineral Resource. Along strike and down dip lode extensions have been highlighted in the body of this Mineral Resource report. |
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Section 3 Estimation and Reporting of Mineral Resources
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Database integrity |
Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. Data validation procedures used. |
The data base is systematically audited by PRU geologists. All drill logs are validated digitally by the database geologist once assay results are returned from the laboratory. In 2010, RUL reviewed the logging of several holes and validated the records in the database against the drill core and logging boards. No significant errors were noted. RPM performed data audits in Surpac. |
| Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. |
Site visits have been conducted by David Price (RUL) in January 2007, Paul Payne (RUL) in January 2008, and Aaron Green (RPM) in October 2010. On each occasion, the deposit area, the core logging and sampling facility, and drilling and sampling operations were viewed. Aaron Green inspected the main laboratory used by PRU. Notes and photos were taken. Discussions were held with site personnel regarding drilling and sampling procedures. No major issues were encountered. |
| Geological interpretation |
Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. |
The confidence in the geological interpretation is considered to be good and is based on good quality drilling. The deposit consists of moderate to steeply dipping mineralised sediment lodes which have been interpreted based on logging of samples taken at regular intervals from angled drill holes. |
| Dimensions | The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. |
The Bokitsi Mineral Resource area extends over a strike length of 1,760m from 3,790mN to 5,550mN. The vertical extent of the Mineral Resource is 280m from surface at 1,180mRL to 900mRL. |
| Estimation and modelling techniques |
The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. |
Using parameters derived from modelled variograms, Ordinary Kriging (OK) was used to estimate average block grades within the deposit. Surpac software was used for the estimations. Top-cuts of between 10g/t and 50g/t were used for the sediment hosted domains. A total of 20 samples were cut. The parent block dimensions used were 10m NS by 5m EW by 10m vertical with sub-cells of 2.5m by 1.25m by 2.5m. The parent block size was selected on the basis of being approximately 50% of the average drill hole spacing in the deposit. Historical production records were available for shallow oxidepits completed in the 1990’s. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. The assumptions made regarding recovery of by- products. Estimation of deleterious elements or other non- grade variables of economic significance (eg sulphur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation was used to control the resource estimates. Discussion of basis for using or not using grade cutting or capping. |
RPM has completed numerous Mineral Resource estimates for the deposit since 2009. Each successive update was based on the previous estimate and extended with additional drilling data. No assumptions have been made regarding recovery of by-products. No estimation of deleterious elements was carried out. Only Au was interpolated into the block model. An orientated ‘ellipsoid’ search was used to select data and was based on parameters taken from the variography or the observed lode geometry. Three passes were used for each domain. The first pass used a range of 50m, with a minimum of 10 samples. For the second pass, the range was extended to 100m, with a minimum of 6 samples. For the final pass, the range was extended to 200m, with a minimum of 1 sample. A maximum of 40 samples was used for all 3 passes. Selective mining units were not modelled in the Mineral Resource model. The block size used in the model was based on drill sample spacing and lode orientation. Only Au assay data was available, therefore correlation analysis was not possible. The deposit mineralisation was constrained by wireframes constructed using a 0.2g/t Au cut-off grade in association with logged lithology codes. The wireframes were applied as hard boundaries in the estimate. Statistical analysis was carried out on data from all lodes. The high coefficient of variation and the scattering of high grade values observed on the histogram for some of the objects suggested that high grade cuts were required if linear grade interpolation was to be carried out. As a result high grade cuts of between 10g/t and 50g/t were applied, resulting in a total of 20 samples being cut. A three step process was used to validate the model. A qualitative assessment was completed by slicing sections through the block model in positions coincident with drilling. A quantitative assessment of the estimate was completed by comparing the average Au grades of the composite file input against the Au block model output for all the resource objects. A trend analysis was completed by comparing the interpolated blocks to the sample composite data within the granite domain. This analysis was completed for 20m northings. Validation plots showed good correlation between the composite grades and the block model grades. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. |
||
| Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. |
Tonnages and grades were estimated on a dry in situ basis. No moisture values were reviewed. |
| Cut-off parameters |
The basis of the adopted cut-off grade(s) or quality parameters applied. |
The Mineral Resource has been reported at a 0.4g/t Au cut-off based on assumptions about economic cut-off grades for open pit mining. PRU is currently mining the AAF deposit which formspart of the Edikan Mine Project area. |
| Mining factors or assumptions |
Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. |
The AAF deposit is currently being mined using open pit techniques. The proximity of the Bokitsi deposit to Edikan and the shallow, higher grade nature of the deposit suggests there is good potential for mining using both open pit and underground methods. |
| Metallurgical factors or assumptions |
The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. |
Metallurgical test-work was undertaken by PRU in 2011 as part of the DFS. Mineralisation characteristics of the sediment hosted mineralisation at Bokitsi are different to the mineralisation currently being processed at the Edikan operation. Metallurgical response is not as favourable as AAF but testwork has shown that gold recovery from Bokitsi is still adequate. |
| Environmental factors or assumptions |
Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. |
The Project is not subject to any environmental liabilities except for a progressive decommissioning and reclamation plan for the closed Ayanfuri heap leach mine. |
| Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones |
A recent study by PRU determined that the previous densities assigned to fresh granite and sediment material were probably too high. A program of submitting existing drill core for analysis was instigated in June 2014. A total of 485 existing drill core samples were sent to commercial laboratories for analysis. Results suggested the fresh granite material had a density in the order of 2.7t/m3and that fresh |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. |
sediment had a density of 2.77t/m3. These values were used in the current RPM block model. Measurements were determined by wax coating samples and immersing in water. RPM recommends an ongoing program of submitting suitable core samples for density analysis from any future diamond drilling programs. |
|
| Classification | The basis for the classification of the Mineral Resources into varying confidence categories. Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). Whether the result appropriately reflects the Competent Person’s view of the deposit. |
Mineral Resources were classified in accordance with the Australasian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC, 2012). The Mineral Resource was classified as Measured, Indicated and Inferred Mineral Resource on the basis of data quality, sample spacing, and lode continuity. The Measured portion of the Mineral Resource was defined where the drill spacing was predominantly at 20m by 20m, and continuity of mineralisation was robust. The Indicated portion of the Mineral Resource was defined where the drill spacing was predominantly at 40m by 20m, and continuity of mineralisation was evident. The portions of the deposit classified as Inferred Mineral Resource include sparsely tested depth extensions of the main zones, and small zones peripheral to the main structures which appear to have poor clear lateral continuity or are untested. The input data is comprehensive in its coverage of the mineralisation and does not favour or misrepresent in-situ mineralisation. The definition of mineralised zones is based on high level geological understanding producing a robust model of mineralised domains. This model has been confirmed by infill drilling which supported the interpretation. Validation of the block model shows good correlation of the input data to the estimated grades. The Mineral Resource estimate appropriately reflects the view of the Competent Person. |
| Audits or reviews |
The results of any audits or reviews of Mineral Resource estimates. |
Internal audits have been completed by RPM which verified the technical inputs, methodology, parameters and results of the estimate. |
| Discussion of relative accuracy/ confidence |
Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical |
The Bokitsi Mineral Resource estimate has been reported with a high degree of confidence. The lode geometry and continuity has been interpreted to reflect the Mineral Resource classification. The data quality is good and the |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. |
drill holes have detailed logs produced by qualified geologists. Recognised laboratories have been used for all analyses. The Mineral Resource statement relates to global estimates of tonnes and grade. The deposit is not currently being mined. Historical production records are available for the deposit. |
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ATTACHMENT 5
Chirawewa Deposit
JORC Code (2012) Table 1
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Section 1 Sampling Techniques and Data
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Sampling techniques |
Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. |
Samples at Chirawewa were collected using drilling techniques such as Reverse Circulation (RC) and Diamond Drilling (DD). Holes were generally angled at 60° towards grid west or east to optimally intersect the mineralised zones. Some RC drill holes have diamond tails. Historical RC samples were collected as 4m composites until potential mineralisation was expected at which time samples were collected at 1m intervals from a rig mounted cyclone into large numbered plastic bags. Recent PRU drilling has used 2m composite samples, and then 1m samples through potential mineralisation. Diamond core was generally sampled at even 1m intervals. Sampling and QAQC procedures were carried out to industry standards. Rig mounted riffle splitters were used to split RC samples and minimize bias. Diamond core was cut in half using a diamond saw and the right hand side of the core was always submitted for analysis with the left side being stored in trays on site. Approximately 5% of all RC samples were sent to the Intertek (formerly TWL) laboratory for 24hr bottle roll with AAS finish. All other RC samples and Diamond half core were analysed by 50g Fire Assay and AAS finish. Samples were sent to Intertek Laboratories (Gh) Ltd at Tarkwa/Ghana (24%), ALS (35%), TWL (18%), and SGS laboratories (2%). Historical sampling and assaying methods are unknown and represent 22% of the supplied assaydata. |
| Drilling techniques |
Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face- sampling bit or other type, whether core is oriented and if so, by what method, etc). |
RC drilling comprising 105mm diameter face sampling bit. Diamond drilling carried out with HQ2 and NQ2 sized equipment. |
| Drill sample recovery |
Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. |
Recoveries from historical drilling are unknown. Actual recoveries from PRU diamond drilling recorded in the database and averaged 93% with no significant issues noted. RC samples were visually checked for recovery, moisture and contamination. No relationship exists between sample recovery and grade. |
| Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. The total length and percentage of the relevant intersections logged. |
All holes were field logged by company geologists. Weathering, lithology, alteration, structure, mineralogy and veining information were recorded. RC chips are glued to boards as a visual reference of every hole. Logging of diamond core additionally recorded recovery, core strength, orientation, roughness, and infill type. Diamond core was photographed. All drill holes were logged in full. Logging was qualitative and quantitative in nature. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Sub-sampling techniques and sample preparation |
If core, whether cut or sawn and whether quarter, half or all core taken. If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub- sampling stages to maximise representivity of samples. Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Whether sample sizes are appropriate to the grain size of the material being sampled. |
HQ2 and NQ2 core was cut in half using a core saw. All samples were collected from the same side of the core. RC samples were collected at the rig using riffle splitters. Samples were predominantly dry. Sampling of diamond core and RC chips uses industry standard techniques. After drying the sample is subject to a primary crush, then pulverised so that 90% passes a -75um sieve. Field QC procedures involved the use of certified reference materials (1 in 20), and field duplicates (1 in 20). Field duplicates were taken on 1m composites for RC using a riffle splitter. Sample sizes are considered appropriate to correctly represent the moderately nuggetty gold mineralisation based on: the style of mineralisation, the thickness and consistency of the intersections, the sampling methodology and assay value ranges for Au. |
| Quality of assay data and laboratory tests |
The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. |
The analytical techniques used Fire Assay on 50g pulp samples with AAS finish. Historically, RC samples were subject to BLEG bottle roll on 1kg samples with AAS finish. This method approaches total dissolution of most minerals. No geophysical tools were used to determine any element concentrations used in this resource estimate. Sample preparation checks for fineness were carried out by the laboratory as part of internal procedures to ensure the grind size of 90% passing 75µm was being attained. Laboratory QAQC includes the use of internal standards using certified reference material, and pulp replicates. Certified reference materials demonstrate that sample assay values are accurate. The QAQC results confirm that acceptable levels of accuracy and precision have been established. |
| Verification of sampling and assaying |
The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. |
The PRU logging process involves placing RC drill samples for each 1m interval onto a board to form a visual log of the entire hole. PRU senior exploration personnel verified the significant intersections by comparing the returned assay results to the photographs of the ‘chip boards’. Twinned holes have not been drilled. Primary data is entered on hard copies in the field, then entered digitally using LogChiefSoftware (Maxwell GeoServices). This data is directly imported into the central Datashed database (Maxwell GeoServices). Assay values that were below detection limit were adjusted to equal half of the detection limit value. Intervals with no samples were left blank in the database(updated from the -9 |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Discuss any adjustment to assay data. |
value used by PRU). | |
| Location of data points |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. |
Prior to 2012, a local grid, including baseline, was established at Edikan by Cluff Plc using qualified surveyors. PRU surveyors have since been used to locate all drill collars in local grid co-ordinates. PRU drill holes are surveyed down hole at 10m to 30m intervals using either Reflex or Flexit multi-shot equipment. Historical RC holes have not been down hole surveyed and are assumed to be straight. Historical diamond holes were down hole surveyed using either acid tubes or a single shot camera. For recent drill programs, collars have been located in UTM, WGS84, Zone 30N co-ordinates and transformed to local grid. True azimuths were converted to local by subtracting 43 from the true value. Local RL elevations were adjusted by adding 1,000m to avoid negative values. This was not done for the initial Mineral Resource estimates. Topographic surface is based on survey points of the existing open pits and drill collars, and merged with the regional topographic surface. The quality of the surface immediately above the mineralised lodes has been surveyed with a high degree of confidence. |
| Data spacing and distribution |
Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied. |
The nominal resource drill hole spacing is 20m by 20m. The drill hole spacing and distribution is considered sufficient to establish the degree of continuity appropriate for the Mineral Resource estimation procedures. Samples have been composited to 4m or 2m intervals with 1m sampling intervals through expected mineralised zones. |
| Orientation of data in relation to geological structure |
Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. |
Drill holes are angled to grid west or east, which is approximately perpendicular to the orientation of the mineralised trends. Due to the orientation of drill holes to the east or west, two holes have been drilled down dip within an east dipping sediment lode. Adjacent drill holes orientated to the west have shown that sampling bias from those two holes is not a significant issue. |
| Sample security | The measures taken to ensure sample security. |
Chain of custody is managed by PRU. Samples are stored on site and collected by laboratory employees. PRU employees have no further involvement in the preparation or analysis of the samples. |
| Audits or reviews |
The results of any audits or reviews of sampling techniques and data. |
A review of sampling techniques was carried out on each site visit by RPM, the most recent in 2010. |
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Section 2 Reporting of Exploration Results
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Mineral tenement and land tenure status |
Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The security of the tenure held at the time of reporting along with any known impediments to obtaining a license to operate in the area. |
The deposit is located within the Nanankaw Mining Lease ML1110/1994 which is wholly owned by PRU. The Mining Lease was granted for a term of 15 years and expires 30 December 2024 The tenements are in good standing. |
| Exploration done by other parties |
Acknowledgment and appraisal of exploration by other parties. |
Previous companies to have held the ground include Cluff Mining and Ashanti Goldfields. Exploration activities included RC and Diamond drilling. |
| Geology | Deposit type, geological setting and style of mineralisation. |
The Edikan deposits occur near the western flank of the Ashanti Greenstone Belt along the Obuasi-Akropong gold corridor. The Central Ashanti property is underlain principally by Paleoproterozoic Birimian metasediments of the Kumasi-Afema basin, positioned between the Ashanti and Sefwi Greenstone Belts. The flysch type metasediments consist of dacitic volcaniclastics, greywackes plus argillaceous (phyllitic) sediments, intensely folded, faulted and metamorphosed to upper greenschist facies. Minor cherty and manganiferous exhalative sediments are locally present, and graphitic schists coincide with the principal shear (thrust) zones. Numerous small Basin-type or Cape Coast-type granitoids have intruded the sediments along several regional structures. Gold mineralisation has been identified within, or is associated with, the margins of a granitoid intrusive which has intruded into a sequence of metasediments. Mineralisation is typically 20- 120m wide and remains open at depth. Mineralisation is associated with minor quartz veining and sulphides which are predominantly pyrite. |
| Drill hole information |
A summary of all information material to the under-standing of the exploration results including a tabulation of the following information for all Material drill holes: easting and northing of the drill hole collar elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar dip and azimuth of the hole down hole length and interception depth hole length If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. |
Exploration results are not being reported. Drill hole locations are shown on the map within the body of this Mineral Resource report. Significant drill hole intersections have been previously reported to the ASX. In the opinion of PRU all material drill results have been adequately reported. |
| Data | In reporting Exploration Results, weighting |
Exploration drill results are not being reported. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| aggregation methods |
averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. The assumptions used for any reporting of metal equivalent values should be clearly stated. |
No aggregation of intercepts was carried out. Drilling intervals are predominantly even 1m, or composites of 2m or 4m. Mineralised composites are re-split to 1m for re-assay. Metal equivalent values are not being reported. |
| Relationship between mineralisation widths and intercept lengths |
These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g.’down hole length, true width not known’). |
Drill holes are angled to local grid which is approximately perpendicular to the orientation of the mineralised trend. |
| Diagrams | Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. |
A plan showing Chirawewa drilling is included within this Mineral Resource report. |
| Balanced Reporting |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. |
Drill holes have been accurately located by PRU surveyors using the local grid system. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Other substantive exploration data |
Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. |
Ongoing bulk density determinations have been conducted by PRU using existing stored drill core. |
| Further work | The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large- scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. |
An infill drilling program is planned which will be drilled from the pit floor once the pit has been dewatered Along strike and down dip lode extensions have been highlighted in the body of this Mineral Resource report. |
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Section 3 Estimation and Reporting of Mineral Resources
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Database integrity |
Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. Data validation procedures used. |
The data base is systematically audited by PRU geologists. All drill logs are validated digitally by the database geologist once assay results are returned from the laboratory. In 2010, RUL reviewed the logging of several holes and validated the records in the database against the drill core and logging boards. No significant errors were noted. RPM performed data audits in Surpac. |
| Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. |
Site visits have been conducted by David Price (RUL) in January 2007, Paul Payne (RUL) in January 2008, and Aaron Green (RPM) in October 2010. On each occasion, the deposit area, the core logging and sampling facility, and drilling and sampling operations were viewed. Aaron Green inspected the main laboratory used by PRU. Notes and photos were taken. Discussions were held with site personnel regarding drilling and sampling procedures. No major issues were encountered. |
| Geological interpretation |
Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. |
The confidence in the geological interpretation is considered to be good and is based on good quality drilling. The deposit consists of steeply dipping mineralised granite and sediment lodes which have been interpreted based on logging of samples taken at regular intervals from angled drill holes. |
| Dimensions | The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. |
The Chirawewa Mineral Resource area extends over a strike length of 1,120m (from 3,780mN – 4,900mN), has an outcropping (within the existing pit) average width of 55m (3,900mE – 3,955mE) and includes the 310m vertical interval from 1,190mRL to 880mRL. |
| Estimation and modelling techniques |
The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. |
Using parameters derived from modelled variograms, Ordinary Kriging (OK) was used to estimate average block grades within Objects 1 and 4, and Inverse Distance Squared (ID2) was used to estimate average block grades within the remaining objects. Surpac software was used for the estimations. A top-cut of 10g/t was appropriate for all objects, apart from Object 4 where a 15g/t top- cut was used for oxide mineralisation and 20g/t Au top-cut was used for fresh mineralisation based on statistical analysis. A total of 31 samples were cut. The parent block dimensions used were 10m NS by5m EW by10m vertical with sub-cells of 2.5m |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. The assumptions made regarding recovery of by- products. Estimation of deleterious elements or other non- grade variables of economic significance (eg sulphur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation was used to control the resource estimates. Discussion of basis for using or not using grade cutting or capping. |
by 1.25m by 2.5m. The parent block size was selected on the basis of being approximately 50% of the average drill hole spacing in the deposit. No historical production records were available. RPM has completed numerous Mineral Resource estimates for the deposit since 2009. Each successive update was based on the previous estimate. No assumptions have been made regarding recovery of by-products. No estimation of deleterious elements was carried out. Only Au was interpolated into the block model. An orientated ‘ellipsoid’ search was used to select data and was based on parameters taken from the variography or the observed lode geometry. Three passes were used for each domain. The first pass used a range of 50m, with a minimum of 10 samples. For the second pass, the range was extended to 100m, with a minimum of 6 samples. For the final pass, the range was extended to 200m, with a minimum of 2 samples. A maximum of 40 samples was used for all 3 passes. Selective mining units were not modelled in the Mineral Resource model. The block size used in the model was based on drill sample spacing and lode orientation. Only Au assay data was available, therefore correlation analysis was not possible. The deposit mineralisation was constrained by wireframes constructed using a 0.2g/t Au cut-off grade in association with logged lithology codes. The wireframes were applied as hard boundaries in the estimate. Statistical analysis was carried out on data from 14 lodes. The high coefficient of variation and the scattering of high grade values observed on the histogram for some of the objects suggested that high grade cuts were required if linear grade interpolation was to be carried out. As a result high grade cuts of 10g/t for all domains, except Object 4 where a 15g/t Au cut was used for oxide mineralisation and 20g/t Au cut was used for fresh mineralisation were applied, resulting in a total of 31 samples being cut. A three step process was used to validate the model. A qualitative assessment was completed by slicing sections through the block model in positions coincident with drilling. A quantitative assessment of the estimate was completed by comparing the average Au grades of the composite file input against the Au block model output for all the resource objects. A trend analysis was completed by comparing the interpolated blocks to the sample composite data within the granite domain. This analysis was completed for 20m northings and 10m bench heights. Validation plots showed good correlation between the composite grades and the block model grades. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. |
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| Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. |
Tonnages and grades were estimated on a dry in situ basis. No moisture values were reviewed. |
| Cut-off parameters |
The basis of the adopted cut-off grade(s) or quality parameters applied. |
The Mineral Resource has been reported at a 0.4g/t Au cut-off based on assumptions about economic cut-off grades for open pit mining. PRU are currently mining the AAF deposit which formspart of the Edikan Mine Project area. |
| Mining factors or assumptions |
Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. |
The AAF deposit is currently being mined using open pit techniques. The Chirawewa deposit is of similar style to that of the AAF deposit and could be mined using both open pit and underground methods. |
| Metallurgical factors or assumptions |
The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. |
Extensive metallurgical test-work was completed on material from a number of deposits within Edikan Project area, by AMMTEC Pty Ltd in Perth for Cluff Plc in the early 1990’s. This focused on CIL test-work on both oxide and sulphide material and later to heap leach. Preliminary amalgamation and cyanidation results using bottle roll methodology confirmed the free milling nature of both the oxide and granite mineralisation. Metallurgical test-work was undertaken by PRU in 2011 aspart of the DFS. |
| Environmental factors or assumptions |
Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. |
The Project is not subject to any environmental liabilities except for a progressive decommissioning and reclamation plan for the closed Ayanfuri heap leach mine. |
| Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately accountfor |
A recent study by PRU determined that the current densities assigned to fresh granite and sediment material were likely too high. A program of submitting existing drill core for analysis was instigated in June 2014. A total of 485 existing drill core samples were sent to commercial laboratories for analysis. Results |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. |
suggested the fresh granite material had a density in the order of 2.7t/m3and that fresh sediment had a density of 2.77t/m3. These values were used in the current RPM block model. Measurements were determined by wax coating samples and immersing in water. RPM recommends an ongoing program of submitting suitable core samples for density analysis from any future diamond drilling programs. |
|
| Classification | The basis for the classification of the Mineral Resources into varying confidence categories. Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). Whether the result appropriately reflects the Competent Person’s view of the deposit. |
Mineral Resources were classified in accordance with the Australasian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC, 2012). The resource was classified as Indicated and Inferred Mineral Resource on the basis of data quality, sample spacing, and lode continuity. The Indicated portion of the Mineral Resource was defined where the drill spacing was predominantly at 20m by 20m, and continuity of mineralisation was good. The portions of the deposit classified as Inferred Mineral Resource include sparsely tested depth extensions of the main zones, and small zones peripheral to the main structures which appear to have poor clear lateral continuity or are untested. The input data is comprehensive in its coverage of the mineralisation and does not favour or misrepresent in-situ mineralisation. The definition of mineralised zones is based on high level geological understanding producing a robust model of mineralised domains. This model has been confirmed by infill drilling which supported the interpretation. Validation of the block model shows good correlation of the input data to the estimated grades. The Mineral Resource estimate appropriately reflects the view of the Competent Person. |
| Audits or reviews |
The results of any audits or reviews of Mineral Resource estimates. |
Internal audits have been completed by RPM which verified the technical inputs, methodology, parameters and results of the estimate. |
| Discussion of relative accuracy/ |
Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or |
The Chirawewa Mineral Resource estimate has been reported with a high degree of confidence. The lode geometry and continuity has been |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| confidence | procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. |
interpreted to reflect the applied level of Indicated and Inferred Mineral Resource. The data quality is good and the drill holes have detailed logs produced by qualified geologists. Recognised laboratories have been used for all analyses. The Mineral Resource statement relates to global estimates of tonnes and grade. The deposit is not currently being mined. Historical production records are not available for the deposit. |
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ATTACHMENT 6
Esuajah North Deposit
JORC Code (2012) Table 1
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Section 1 Sampling Techniques and Data
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Sampling techniques |
Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. |
Drill holes included in the resource were sampled using Reverse Circulation (RC) and diamond drill (DD) holes on a nominal 40m by 40m grid spacing (with localised areas of 20m by 20m). A total of 160 holes were included in the resource for a total 3,295m within the resource wireframes. Holes were generally angled at 50° towards grid west or east to optimally intersect the mineralised zones. Drill hole collars were picked up and down hole surveyed by qualified surveyors. RC samples were collected by a riffle splitter at 1m to 2m intervals. Diamond core was cut in half using a core saw with sampling at geological boundaries. All samples were collected from the same side of the core. Sampling and QAQC procedures were carried out to industry standards. Samples from the first 60 RC drill holes were sent to Transworld Laboratory for 24hr bottle roll with AAS finish. All subsequent RC samples were analysed by 50g Fire Assay at ALS Kumasi. Diamond half core samples analysed by 50g Fire Assay and AAS finish. |
| Drilling techniques |
Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face- sampling bit or other type, whether core is oriented and if so, by what method, etc). |
RC drilling comprising 105mm diameter face sampling bit. Diamond drilling carried out with HQ2 and NQ2 sized equipment. |
| Drill sample recovery |
Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. |
Recoveries from historical drilling are unknown. Actual recoveries from PRU diamond drilling are recorded in the main Edikan database and average 96% with no significant issues noted. No actual recoveries were included in the data supplied for the Dadieso deposit. RC samples were visually checked for recovery, moisture and contamination. |
| Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. |
All holes were field logged by company geologists. Weathering, lithology, alteration, structure, mineralogy and veining information were recorded. RC chips are glued to boards as a visual reference of every hole. Logging of diamond core also recorded recovery, core strength, orientation, roughness, and infill type. Diamond core was photographed. All drill holes were logged in full. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The total length and percentage of the relevant intersections logged. |
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| Sub-sampling techniques and sample preparation |
If core, whether cut or sawn and whether quarter, half or all core taken. If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub- sampling stages to maximise representivity of samples. Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Whether sample sizes are appropriate to the grain size of the material being sampled. |
HQ2 and NQ2 core was cut in half using a core saw. All samples were collected from the same side of the core. RC samples were collected at the rig using riffle splitters. Samples were predominantly dry. Less than 0.5% of samples were recorded as ‘wet’ in the supplied data in the ‘sampquality’ field, although 55% of records in this field are blank. Sampling of diamond core and RC chips uses industry standard techniques. After drying the sample is subject to a primary crush, then pulverised so that 90% passes a -75um sieve. Field QC procedures involved the use of certified reference materials (1 in 20), and field duplicates (1 in 20). Field duplicates were taken on 1m to 2m composites for RC using a riffle splitter. Sample sizes are considered appropriate to correctly represent the moderately nuggetty gold mineralisation based on: the style of mineralisation, the thickness and consistency of the intersections, the sampling methodology and assay value ranges for Au. |
| Quality of assay data and laboratory tests |
The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. |
The analytical techniques used Fire Assay on 50g samples or BLEG bottle roll on 1kg samples both with AAS finish. This method approaches total dissolution of most minerals. No geophysical tools were used to determine any element concentrations used in this resource estimate. Sample preparation checks for fineness were carried out by the laboratory as part of internal procedures to ensure the grind size of 90% passing 75µm was being attained. Laboratory QAQC includes the use of internal standards using certified reference material, and pulp replicates. Certified reference materials demonstrate that sample assay values are accurate. Aaron Green of RPM visited the main laboratory in October 2010. |
| Verification of sampling and assaying |
The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. Discuss any adjustment to assay data. |
RPM has not independently verified significant intersections of mineralisation. DKRC067 and DKRC068 are twinned holes and display similar down hole grades. The east and west dipping holes on 40m spacing result in ‘crossing’ of drill traces at depth. Primary data is entered on hardcopies in the field and then entered digitally using Log Chief Software (Maxwell GeoServices). This data is then directly imported into the PRU central database (DataShed/Maxwell GeoServices). Assay values that were below detection limit were adjusted to equal half of the detection limit value. Intervals with no samples were left blank in the database (updated from the -9 value used byPRU). |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Location of data points |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. |
Prior to 2012, a local grid, including baseline, was established at Edikan by Plc (Cluff) using qualified surveyors. Qualified surveyors were used to locate all drill collars in local grid co- ordinates. For recent drill programs, collars have been located in UTM, WGS84, Zone 30N co-ordinates and transformed to local grid. True azimuths were converted to local by subtracting 43 from the true value. Local RL elevations were adjusted by adding 1,000m to avoid negative values. This was not done for the previous resource estimates. PRU drill holes are surveyed down hole at 10m to 30m intervals using either Reflex or Flexit multi-shot equipment. Historical RC holes have not been down hole surveyed and are assumed to be straight. The average depth of these holes is 50m. Topographic surface based on 1,181 historic pit survey points and 1,955 topographic and drill hole surveyed locations byPRU surveyors. |
| Data spacing and distribution |
Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied. |
The nominal drill hole spacing is 40m by 40m. The mineralised domains have demonstrated sufficient continuity in both geological and grade continuity to support the definition of Mineral Resource, and the classifications applied under the 2012 JORC Code. Samples have been composited to 2m lengths using best fit techniques. One residual sample length was excluded. |
| Orientation of data in relation to geological structure |
Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. |
Drill holes are angled to grid east and west, which is approximately perpendicular to the orientation of the interpreted mineralised trends. No orientation based sampling bias has been identified in the data. |
| Sample security | The measures taken to ensure sample security. |
Chain of custody is managed by PRU. Samples are stored on site and collected by Intertek employees. PRU employees have no further involvement in the preparation or analysis of the samples. |
| Audits or reviews |
The results of any audits or reviews of sampling techniques and data. |
A review of sampling techniques was carried out on each site visit by RPM the most recent in 2010. |
Section 2 Reporting of Exploration Results
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Mineral tenement and land tenure status |
Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The security of the tenure held at the time of |
The deposit is located within the Nanankaw Mining Lease ML1110/1994 which is wholly owned by PRU. The Mining Lease was granted for a term of 15 years and expires 30 December 2024 The tenements are in good standing. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| reporting along with any known impediments to obtaining a license to operate in the area. |
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| Exploration done by other parties |
Acknowledgment and appraisal of exploration by other parties. |
Previous companies to have held the ground include Cluff Mining and Ashanti Goldfields. Exploration activities included RC and Diamond drilling. |
| Geology | Deposit type, geological setting and style of mineralisation. |
The Edikan deposits occur near the western flank of the Ashanti Greenstone Belt along the Obuasi-Akropong gold corridor. The Central Ashanti property is underlain principally by Paleoproterozoic Birimian metasediments of the Kumasi-Afema basin, positioned between the Ashanti and Sefwi Greenstone Belts. The flysch type metasediments consist of dacitic volcaniclastics, greywackes plus argillaceous (phyllitic) sediments, intensely folded, faulted and metamorphosed to upper greenschist facies. Minor cherty and manganiferous exhalative sediments are locally present, and graphitic schists coincide with the principal shear (thrust) zones. Numerous small Basin-type or Cape Coast-type granitoids have intruded the sediments along several regional structures. Gold mineralisation has been identified within, or is associated with, the margins of a granitoid intrusive which has intruded into a sequence of metasediments. Mineralisation is typically 20- 120m wide and remains open at depth. Mineralisation is associated with minor quartz veining and sulphides which are predominantly pyrite. |
| Drill hole information |
A summary of all information material to the under-standing of the exploration results including a tabulation of the following information for all Material drill holes: easting and northing of the drill hole collar elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar dip and azimuth of the hole down hole length and interception depth hole length If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. |
Exploration results are not being reported. Drill hole locations are shown on the map within the body of this Mineral Resource report. Significant drill hole intersections have been previously reported to the ASX. In the opinion of PRU all material drill results have been adequately reported. |
| Data aggregation methods |
In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. |
Exploration drill results are not being reported. No aggregation of intercepts was carried out. Drilling intervals are predominantly even 1m, or composites of 2m or 4m. Mineralised composites are re-split to 1m for re-assay. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The assumptions used for any reporting of metal equivalent values should be clearly stated. |
Metal equivalent values are not being reported. |
|
| Relationship between mineralisation widths and intercept lengths |
These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g.’down hole length, true width not known’). |
Drill holes are angled to local grid which is approximately perpendicular to the orientation of the mineralised trend. |
| Diagrams | Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. |
Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Balanced Reporting |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. |
Drill holes have been accurately located by PRU surveyors using the local grid system. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Other substantive exploration data |
Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. |
Ongoing bulk density determinations have been conducted by PRU using existing stored drill core. |
| Further work | The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large- scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. |
No further exploration planned at Esuajah North. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
Section 3 Estimation and Reporting of Mineral Resources
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Database integrity |
Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. Data validation procedures used. |
The data base is systematically audited by PRU geologists. All drill logs are validated digitally by the database geologist once assay results are returned from the laboratory. In 2010, RUL reviewed the logging of several holes and validated the records in the database against the drill core and logging boards. No significant errors were noted. RPM validated the 2013 data against previous data from the 2012 estimate. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| RPM alsoperformed data audits in Surpac. |
||
| Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. |
Site visits have been conducted by David Price (RUL) in January 2007, Paul Payne (RUL) in January 2008, and Aaron Green (RPM) in October 2010. On each occasion, the deposit area, the core logging and sampling facility, and drilling and sampling operations were viewed. Aaron Green inspected the main laboratory used by PRU. Notes and photos were taken. Discussions were held with site personnel regarding drilling and sampling procedures. No major issues were encountered. |
| Geological interpretation |
Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. |
The confidence in the geological interpretation is considered to be robust. The deposit primarily consists of a steeply dipping mineralised granite lode. Surface outcropping of mineralisation confirms the geometry of the mineralisation. Geological logging of drilling has generally confirmed the geometry of the mineralisation. |
| Dimensions | The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. |
The Esuajah North resource area extends over a strike length of 500m (from 7,000mN to 7,500mN), and includes the 470m vertical interval from 1,170mRL to 700mRL. The overall plan width of the mineralised lodes is 275m and extends from 2,225mE to 2,500mE. |
| Estimation and modelling techniques |
The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. The assumptions made regarding recovery of by- products. Estimation of deleterious elements or other non- grade variables of economic significance (eg |
Using parameters derived from modeled variograms, Ordinary Kriging (OK) was used to estimate average block grades within the lodes. Surpac software was used for the estimations. A high grade cut of 20g/t was applied to all lodes. A total of 30 samples were cut. The parent block dimensions used were 10m NS by 10m EW by 20m vertical with sub-cells of 2.5m by 2.5m by 5m. The parent block size was selected on the basis of being approximately 50% of the average drill hole spacing in the deposit. Previous mining has occurred at the deposit as part of the Edikan Heap Leach Project which commenced production in November 1994 although mining records are not available for the Esuajah North deposit. No estimation of deleterious elements was carried out. OnlyAu was interpolated into the |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| sulphur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation was used to control the resource estimates. Discussion of basis for using or not using grade cutting or capping. The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. |
block model. An orientated ‘ellipsoid’ search was used to select data and was based on parameters taken from the variography and orientated to individual lode geometry. Three passes were used for each domain. The first pass used a range of 40m, with a minimum of 10 samples. For the second pass, the range was extended to 100m, with a minimum of 10 samples. For the final pass, the range was extended to 240m, with a minimum of 6 samples. A maximum of 40 samples was used for all 3 passes. No assumptions were made on selective mining units. Only Au assay data was available, therefore correlation analysis was not possible. The deposit mineralisation was constrained by wireframes constructed using a 0.2g/t Au cut-off grade in association with logged lithology codes. The wireframes were applied as hard boundaries in the estimate. A three step process was used to validate the model. A qualitative assessment was completed by slicing sections through the block model in positions coincident with drilling. A quantitative assessment of the estimate was completed by comparing the average Au grades of the composite file input against the Au block model output for all the resource objects. A trend analysis was completed by comparing the interpolated blocks to the sample composite data for the combined lodes. This analysis was completed for 20m northings and 20m bench heights. Validation plots showed good correlation between the composite grades and the block model grades. |
|
| Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. |
Tonnages and grades were estimated on a dry in situ basis. No moisture values were reviewed. |
| Cut-off parameters |
The basis of the adopted cut-off grade(s) or quality parameters applied. |
The Mineral Resource has been reported at a 0.4g/t Au cut-off based on assumptions about economic cut-off grades for open pit mining. PRU are currently mining adjacent deposits within the Edikan Project area. |
| Mining factors or assumptions |
Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the |
RPM has assumed that the deposit could potentially be mined using open pit techniques with some potential for large scale underground mining. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. |
||
| Metallurgical factors or assumptions |
The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. |
Extensive metallurgical testwork was completed on material from a number of deposits within the Edikan Project area, by AMMTEC Pty Ltd in Perth for Cluff Plc in the early 1990’s. This focussed on CIL testwork on both oxide and sulphide material and later to heap leach. Preliminary amalgamation and cyanidation results using bottle roll methodology confirmed the free milling nature of both the oxide and granite mineralisation. Metallurgical testwork was undertaken by PRU in 2011 aspart of the DFS. |
| Environmental factors or assumptions |
Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. |
The Project is not subject to any environmental liabilities except for a progressive decommissioning and reclamation plan for the closed Ayanfuri heap leach mine. |
| Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. |
A total of 956 bulk density determinations have been undertaken at the Edikan Project. 814 samples were from primary rock, 48 were from slightly weathered to strongly weathered material, and 94 were from the transitional zone, which is a fair reflection on the proportion of sulphide Mineral Resources to oxide Mineral Resources. A total of 153 of the bulk density samples were taken from the Esuajah North deposit. The bulk density of the mineralisation has been determined with a high degree of confidence from extensive sampling and measurements. |
| Classification | The basis for the classification of the Mineral Resources into varying confidence categories. |
Mineral Resources were classified in accordance with the Australasian Code for the Reporting of Identified Mineral Resources and Ore Reserves (JORC, 2012). The resource was classified as Measured, Indicated and Inferred Mineral Resource. The Measured portion of the resource was defined where the drill spacing was predominantly closer than 20m by 40m with excellent continuity of the main mineralised zones within the granite. The Indicated portion of the resource was defined where the drill spacingwasgreater than 20m by40m at the |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). Whether the result appropriately reflects the Competent Person’s view of the deposit. |
north and south margins of the granite where continuity of mineralisation was good. Areas of the resource defined at greater than 40m spacing, as well as the sediment to the south of the main granite, were classified as Inferred Mineral Resource. This includes the sparsely intersected depth extension of the mineralised granite. The input data is adequate in its coverage of the mineralisation and does not favour or misrepresent in-situ mineralisation. Infill drilling has confirmed the mineralisation continuity for the main lodes and support the interpretation. Validation of the block model shows good correlation of the input data to the estimated grades. The Mineral Resource estimate appropriately reflects the view of the Competent Person. |
|
| Audits or reviews |
The results of any audits or reviews of Mineral Resource estimates. |
Internal audits have been completed by RPM which verified the technical inputs, methodology, parameters and results of the estimate. |
| Discussion of relative accuracy/ confidence |
Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. |
The relative accuracy of the Mineral Resource estimate is reflected in the reporting of the Mineral Resource as per the guidelines of the 2012 JORC Code. The Mineral Resource statement relates to global estimates of tonnes and grade. The deposit is not currently being mined. |
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ATTACHMENT 7
Esuajah South Deposit
JORC Code (2012) Table 1
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Section 1 Sampling Techniques and Data
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Sampling techniques |
Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. |
Drill holes included in the resource were sampled using Reverse Circulation (RC) and diamond drill (DD) holes on a nominal 20m by 20m grid spacing. A total of 151 holes were included in the resource for a total 13,503m within the resource wireframes. Holes were generally angled at 50° towards grid west or east to optimally intersect the mineralised zones. Drill hole collars were picked up and down hole surveyed by qualified surveyors. RC samples were collected by a riffle splitter at 1m intervals. Diamond core was cut in half using a core saw with sampling at geological boundaries. All samples were collected from the same side of the core. Sampling and QAQC procedures were carried out to industry standards. RC samples sent to Transworld Laboratory for 24hr bottle roll with AAS finish. Diamond half core samples analysed by 50g Fire Assay and AAS finish. |
| Drilling techniques |
Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face- sampling bit or other type, whether core is oriented and if so, by what method, etc). |
RC drilling comprising 105mm diameter face sampling bit. Diamond drilling carried out with HQ2 and NQ2 sized equipment. |
| Drill sample recovery |
Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. |
Recoveries from historical drilling are unknown. Actual recoveries from PRU diamond drilling recorded in the database and averaged 96.7% with no significant issues noted. RC samples were visually checked for recovery, moisture and contamination. |
| Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. |
All holes were field logged by company geologists. Weathering, lithology, alteration, structure, mineralogy and veining information were recorded. RC chips are glued to boards as a visual reference of every hole. Logging of diamond core also recorded recovery, core strength, orientation, roughness, and infill type. Diamond core was photographed. All drill holes were logged in full. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The total length and percentage of the relevant intersections logged. |
||
| Sub-sampling techniques and sample preparation |
If core, whether cut or sawn and whether quarter, half or all core taken. If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub- sampling stages to maximise representivity of samples. Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Whether sample sizes are appropriate to the grain size of the material being sampled. |
HQ2 and NQ2 core was cut in half using a core saw. All samples were collected from the same side of the core. RC samples were collected at the rig using riffle splitters. Samples were predominantly wet but very few occur within the Mineral Resource wireframes. Sampling of diamond core and RC chips uses industry standard techniques. After drying the sample is subject to a primary crush, then pulverised so that 90% passes a -75um sieve. Field QC procedures involved the use of certified reference materials (1 in 20), and field duplicates (1 in 20). Field duplicates were taken on 1m composites for RC using a riffle splitter. Sample sizes are considered appropriate to correctly represent the moderately nuggetty gold mineralisation based on: the style of mineralisation, the thickness and consistency of the intersections, the sampling methodology and assay value ranges for Au. |
| Quality of assay data and laboratory tests |
The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. |
The analytical techniques used Fire Assay on 50g samples or BLEG bottle roll on 1kg samples both with AAS finish. This method approaches total dissolution of most minerals. No geophysical tools were used to determine any element concentrations used in this resource estimate. Sample preparation checks for fineness were carried out by the laboratory as part of internal procedures to ensure the grind size of 90% passing 75µm was being attained. Laboratory QAQC includes the use of internal standards using certified reference material, and pulp replicates. Certified reference materials demonstrate that sample assay values are accurate. Aaron Green of RPM visited the main laboratory in October 2010. |
| Verification of sampling and assaying |
The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. Discuss any adjustment to assay data. |
RPM has not independently verified significant intersections of mineralisation. No twin holes were drilled although the east and west dipping holes on 20m spacing result in ‘crossing’ of drill traces at depth. Primary data is entered on hardcopies in the field and then entered digitally using Log Chief Software (Maxwell GeoServices). This data is then directly imported into the PRU central database (DataShed/Maxwell GeoServices). Assay values that were below detection limit were adjusted to equal half of the detection limit value. Intervals with no samples were left blank in the database (updated from the -9 value used byPRU). |
| Location of | Accuracy and quality of surveys used to locate drill holes(collar and down-hole surveys), trenches, |
Prior to 2012, a local grid, including baseline, was established at Edikan byCluff Plc using |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| data points | mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. |
qualified surveyors. Qualified surveyors were used to locate all drill collars in local grid co- ordinates. For recent drill programs, collars have been located in UTM, WGS84, Zone 30N co-ordinates and transformed to local grid. True azimuths were converted to local by subtracting 43 from the true value. Local RL elevations were adjusted by adding 1,000m to avoid negative values. This was not done for the previous resource estimates. The first 13 Diamond holes were surveyed down hole at 60m intervals and at the end of hole, using acid tests. PRU drill holes are surveyed down hole at 10m to 30m intervals using either Reflex or Flexit multi-shot equipment. Historical RC holes have not been down hole surveyed and are assumed to be straight. The average depth of these holes is 57m. Historical diamond holes were down hole surveyed using either acid tubes or a single shot camera. Topographic surface based on 1,407 survey points of the old pit surveyed in during mining of the pit. A further 630 points were surveyed includingall drill collars,byPRU surveyors. |
| Data spacing and distribution |
Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied. |
The nominal drill hole spacing is 20m by 20m. The mineralised domains have demonstrated sufficient continuity in both geological and grade continuity to support the definition of Mineral Resource, and the classifications applied under the 2012 JORC Code. Samples have been composited to 1m lengths using best fit techniques. Two residual sample lengths were excluded. |
| Orientation of data in relation to geological structure |
Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. |
Drill holes are angled to grid east and west, which is approximately perpendicular to the orientation of the mineralised trends. No orientation based sampling bias has been identified in the data. |
| Sample security | The measures taken to ensure sample security. |
Chain of custody is managed by PRU. Samples are stored on site and collected by Intertek employees. PRU employees have no further involvement in the preparation or analysis of the samples. |
| Audits or reviews |
The results of any audits or reviews of sampling techniques and data. |
A review of sampling techniques was carried out on each site visit by RPM, the most recent in 2010. |
Section 2 Reporting of Exploration Results
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Mineral tenement and land tenure |
Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, |
The deposit is located within the Nanankaw Mining Lease ML1110/1994 which is wholly owned by PRU. The MiningLease wasgranted for a term of 15 |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| status | partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The security of the tenure held at the time of reporting along with any known impediments to obtaining a license to operate in the area. |
years and expires 30 December 2024 The tenements are in good standing. |
| Exploration done by other parties |
Acknowledgment and appraisal of exploration by other parties. |
Previous companies to have held the ground include Cluff Mining and Ashanti Goldfields. Exploration activities included RC and Diamond drilling. |
| Geology | Deposit type, geological setting and style of mineralisation. |
The Edikan deposits occur near the western flank of the Ashanti Greenstone Belt along the Obuasi-Akropong gold corridor. The Central Ashanti property is underlain principally by Paleoproterozoic Birimian metasediments of the Kumasi-Afema basin, positioned between the Ashanti and Sefwi Greenstone Belts. The flysch type metasediments consist of dacitic volcaniclastics, greywackes plus argillaceous (phyllitic) sediments, intensely folded, faulted and metamorphosed to upper greenschist facies. Minor cherty and manganiferous exhalative sediments are locally present, and graphitic schists coincide with the principal shear (thrust) zones. Numerous small Basin-type or Cape Coast-type granitoids have intruded the sediments along several regional structures. Gold mineralisation has been identified within, or is associated with, the margins of a granitoid intrusive which has intruded into a sequence of metasediments. Mineralisation is typically 20- 120m wide and remains open at depth. Mineralisation is associated with minor quartz veining and sulphides which are predominantly pyrite. |
| Drill hole information |
A summary of all information material to the under-standing of the exploration results including a tabulation of the following information for all Material drill holes: easting and northing of the drill hole collar elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar dip and azimuth of the hole down hole length and interception depth hole length If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. |
Exploration results are not being reported. Drill hole locations are shown on the map within the body of this Mineral Resource report. Significant drill hole intersections have been previously reported to the ASX. In the opinion of PRU all material drill results have been adequately reported. |
| Data aggregation methods |
In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short |
Exploration drill results are not being reported. No aggregation of intercepts was carried out. Drillingintervals arepredominantlyeven 1m,or |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. The assumptions used for any reporting of metal equivalent values should be clearly stated. |
composites of 2m or 4m. Mineralised composites are re-split to 1m for re-assay. Metal equivalent values are not being reported. |
|
| Relationship between mineralisation widths and intercept lengths |
These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g.’down hole length, true width not known’). |
Drill holes are angled to local grid which is approximately perpendicular to the orientation of the mineralised trend. |
| Diagrams | Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. |
Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update |
| Balanced Reporting |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. |
Drill holes have been accurately located by PRU surveyors using the local grid system. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Other substantive exploration data |
Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. |
Ongoing bulk density determinations have been conducted by PRU using existing stored drill core. |
| Further work | The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large- scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. |
No further drilling currently planned for the Esuajah South deposit. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. PRU are currently studying the economic viability of underground mining options at the deposit. |
Section 3 Estimation and Reporting of Mineral Resources
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Database integrity |
Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. |
The data base is systematically audited by PRU geologists. All drill logs are validated digitally by the database geologist once assay results are returned from the laboratory. In 2010, RUL reviewed the loggingof several holes and |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Data validation procedures used. |
validated the records in the database against the drill core and logging boards. No significant errors were noted. RPM validated the 2013 data against previous data from the 2010 estimate. One drill hole (AKRDD256) had an incorrect prospect name so had not been used in previous estimates. The dip and depth intervals of down hole surveys for a number of drill holes differed from the 2010 database. PRU instructed RPM to use the 2010 data for those holes as the errors were attributed to converting of the PRU current database to Datashed format. RPM alsoperformed data audits in Surpac. |
|
| Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. |
Site visits have been conducted by David Price (RUL) in January 2007, Paul Payne (RUL) in January 2008, and Aaron Green (RPM) in October 2010. On each occasion, the deposit area, the core logging and sampling facility, and drilling and sampling operations were viewed. Aaron Green inspected the main laboratory used by PRU. Notes and photos were taken. Discussions were held with site personnel regarding drilling and sampling procedures. No major issues were encountered. |
| Geological interpretation |
Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. |
The confidence in the geological interpretation is considered to be good and is based on good quality drilling. The deposit consists of a steeply dipping granite lode and mineralised sediment lodes. Infill drilling has supported and refined the model and the current interpretation is considered robust. Outcropping of mineralisation and host rocks within the previously mined open pit confirm the geometry of the mineralisation. The logging of ‘granite’ is consistent and closely matches the observed mineralisation. Infill drilling has confirmed geological and grade continuity. |
| Dimensions | The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. |
The Esuajah South resource area extends over a strike length of 300m (from 6,070mN – 6,370mN), has an outcropping (within the existing pit) average width of 50m (1,950mE – 2,000mE) and includes the 605m vertical interval from 1,160mRL to 555mRL. |
| Estimation and modelling techniques |
The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. The availability of check estimates, previous estimates and/or mine production records and |
Using parameters derived from modelled variograms, Ordinary Kriging (OK) was used to estimate average block grades within the granite domain. Inverse distance squared (ID2) interpolation was used to estimate block grades within the sediment domain. Surpac software was used for the estimations. A high grade cut of 40g/t was applied to the granite lode, and 15g/t to 30g/t for selected sediment lodes based on statistical analysis. A total of 19 samples were cut. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| whether the Mineral Resource estimate takes appropriate account of such data. The assumptions made regarding recovery of by- products. Estimation of deleterious elements or other non- grade variables of economic significance (eg sulphur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation was used to control the resource estimates. Discussion of basis for using or not using grade cutting or capping. The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. |
The parent block dimensions used were 10m NS by 10m EW by 10m vertical with sub-cells of 2.5m by 2.5m by 2.5m. The parent block size was selected on the basis of being approximately 50% of the average drill hole spacing in the deposit. Reconciliation with historic production records was conducted by RUL in 2010. The discrepancies noted between the model and reported production was attributed to the pit having not been accurately surveyed, and currently filled with water. The mined portion of the model was based on the survey of the pit. No estimation of deleterious elements was carried out. Only Au was interpolated into the block model. An orientated ‘ellipsoid’ search was used to select data and was based on parameters taken from the variography (granite domain only). For the sediment domain, the search ellipse was orientated based on observed lode geometry. Three passes were used for each domain. The first pass used a range of 30m, with a minimum of 6 to 10 samples. For the second pass, the range was extended to 60m, with a minimum of 4 to 6 samples. For the final pass, the range was extended to 180m to 240m, with a minimum of 2 to 4 samples. A maximum of 40 samples was used for all 3 passes for the granite domain, and 30 samples for the sediment domain. No assumptions were made on selective mining units. Only Au assay data was available, therefore correlation analysis was not possible. The deposit mineralisation was constrained by wireframes constructed using a 0.2g/t Au cut-off grade in association with logged lithology codes. The wireframes were applied as hard boundaries in the estimate. A three step process was used to validate the model. A qualitative assessment was completed by slicing sections through the block model in positions coincident with drilling. A quantitative assessment of the estimate was completed by comparing the average Au grades of the composite file input against the Au block model output for all the resource objects. A trend analysis was completed by comparing the interpolated blocks to the sample composite data within the granite domain. This analysis was completed for 20m northings and 20m bench heights. Validation plots showed good correlation between the composite grades and the block model grades. |
|
| Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. |
Tonnages and grades were estimated on a dry in situ basis. No moisture values were reviewed. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Cut-off parameters |
The basis of the adopted cut-off grade(s) or quality parameters applied. |
The Mineral Resource has been reported at a 0.4g/t Au cut-off based on assumptions about economic cut-off grades for open pit mining. PRU are currently mining adjacent granite hosted deposits. |
| Mining factors or assumptions |
Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. |
RPM has assumed that the deposit could potentially be mined using large scale open pit and potentially underground techniques. Small scale open pit mining of the oxide material has previously occurred at Esuajah South. |
| Metallurgical factors or assumptions |
The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. |
Extensive metallurgical testwork was completed on material from a number of deposits within Edikan Project area, by AMMTEC Pty Ltd in Perth for Cluff Plc in the early 1990’s. This focussed on CIL testwork on both oxide and sulphide material and later to heap leach. Preliminary amalgamation and cyanidation results using bottle roll methodology confirmed the free milling nature of both the oxide and granite mineralisation. Metallurgical testwork was undertaken by PRU in 2011 aspart of the DFS. |
| Environmental factors or assumptions |
Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. |
The Project is not subject to any environmental liabilities except for a progressive decommissioning and reclamation plan for the closed Ayanfuri heap leach mine. |
| Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. |
A total of 956 bulk density determinations have been undertaken at the Edikan Project, including 209 from the Esuajah South deposit. Average densities were determined from this analaysis. 814 samples were from primary rock, 48 were from slightly weathered to strongly weathered material, and 94 were from the transitional zone, which is a fair reflection on the proportion of sulphide Mineral Resources to oxide Mineral Resources. The bulk density of the mineralisation has been determined with a high degree of confidence from extensive sampling and measurements. |
| Classification | The basis for the classification of the Mineral Resources into varying confidence categories. |
Mineral Resources were classified in accordance with the Australasian Code for the Reporting of Identified Mineral Resources and Ore Reserves |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). Whether the result appropriately reflects the Competent Person’s view of the deposit. |
(JORC, 2012). The deposit was classified as Measured, Indicated and Inferred Mineral Resource based on data quality, drill hole spacing, and continuity of mineralisation. The portion of the granite where the drill spacing was 20m by 20m or less and demonstrating good lode and grade continuity supported by high kriging efficiencies was classified as Measured Mineral Resource. This was confined to the central portion of the granite domain from surface down to 830mRL. The portion of the deposit where the drill spacing was generally greater than 20m by 20m but still demonstrated good lode and grade continuity was classified as Indicated Mineral Resource. The portion of the deposit classified as Inferred Mineral Resource included areas where the drill spacing was greater than 40m by 40m (generally the deeper portions of the granite), and the zones of mineralisation within the adjacent sediments that were defined by limited drilling. The input data is comprehensive in its coverage of the mineralisation and does not favour or misrepresent in-situ mineralisation. The definition of mineralised zones is based on high level geological understanding producing a robust model of mineralised domains. This model has been confirmed by infill drilling which supported the interpretation. Validation of the block model shows good correlation of the input data to the estimated grades. The Mineral Resource estimate appropriately reflects the view of the Competent Person. |
|
| Audits or reviews |
The results of any audits or reviews of Mineral Resource estimates. |
Internal audits have been completed by RPM which verified the technical inputs, methodology, parameters and results of the estimate. |
| Discussion of relative accuracy/ confidence |
Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. |
The relative accuracy of the Mineral Resource estimate is reflected in the reporting of the Mineral Resource as per the guidelines of the 2012 JORC Code. The Mineral Resource statement relates to global estimates of tonnes and grade. The deposit is not currently being mined. Previous mining of oxide material has been reconciled with the resource model reported in 2010. The model reported a reduced grade compared to production. The mined portion of the model was based on the survey of the mined pit, which has not been accurately surveyed, and is therefore only an estimate of what was mined. |
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ATTACHMENT 8
Mampong Deposit
JORC Code (2012) Table 1
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Section 1 Sampling Techniques and Data
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Sampling techniques |
Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. |
Drill holes included in the resource were sampled using Reverse Circulation (RC) and RC/diamond drill tail (RC/DD) holes on a nominal 40m by 40m grid spacing. A total of 149 holes were included in the resource for a total 3,618m within the resource wireframes. Holes were angled towards grid south to optimally intersect the mineralised zones. Drill hole collars were picked up and down hole surveyed by qualified surveyors. RC samples were collected by a riffle splitter at 1m intervals. Diamond core was cut in half using a core saw with sampling at 1m intervals, locally to geological boundaries. All samples were collected from the same side of the core. Sampling and QAQC procedures were carried out to industry standards. About 6% of all RC samples were sent to ALS Minerals at Kumasi/Ghana for 24hr bottle roll with AAS finish. All other RC samples were analysed by 50g Fire Assay and AAS finish. Diamond half core samples were sent to Intertek Laboratories (Gh) Ltd at Tarkwa/Ghana or to ALS (Ghana) Limited, Ghana, for 50g Fire Assay and AAS finish. |
| Drilling techniques |
Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face- sampling bit or other type, whether core is oriented and if so, by what method, etc). |
RC drilling comprising 105mm diameter face sampling bit. Diamond drilling carried out with HQ2 and NQ2 sized equipment. |
| Drill sample recovery |
Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. |
Recoveries from historical drilling are unknown. Actual recoveries from PRU diamond drilling recorded in the database and averaged 96.7% with no significant issues noted. RC samples were visually checked for recovery, moisture and contamination. No relationship exists between sample recovery and grade. |
| Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) |
All holes were field logged by company geologists. Weathering, lithology, alteration, structure, mineralogy and veining information were recorded. RC chips are glued to boards as a visual reference of every hole. Logging of diamond core additionally recorded recovery, core strength, orientation, roughness, and infill type. Diamond core was |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| photography. The total length and percentage of the relevant intersections logged. |
photographed. All drill holes were logged in full. |
|
| Sub-sampling techniques and sample preparation |
If core, whether cut or sawn and whether quarter, half or all core taken. If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub- sampling stages to maximise representivity of samples. Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Whether sample sizes are appropriate to the grain size of the material being sampled. |
HQ2 and NQ2 core was cut in half using a core saw. All samples were collected from the same side of the core. RC samples were collected at the rig using riffle splitters. Samples were predominantly dry. 1% of samples were recorded as wet in the supplied database in the ‘sampquality’ field. Sampling of diamond core and RC chips uses industry standard techniques. After drying the sample is subject to a primary crush, then pulverised so that 90% passes a -75um sieve. Field QC procedures involved the use of certified reference materials (1 in 20), and field duplicates (1 in 20). Field duplicates were taken on 1m composites for RC using a riffle splitter. Sample sizes are considered appropriate to correctly represent the moderately nuggetty gold mineralisation based on: the style of mineralisation, the thickness and consistency of the intersections, the sampling methodology and assay value ranges for Au. |
| Quality of assay data and laboratory tests |
The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. |
The analytical techniques used Fire Assay on 50g samples or BLEG bottle roll on 1kg samples both with AAS finish. This method approaches total dissolution of most minerals. No geophysical tools were used to determine any element concentrations used in this resource estimate. Sample preparation checks for fineness were carried out by the laboratory as part of internal procedures to ensure the grind size of 90% passing 75µm was being attained. Laboratory QAQC includes the use of internal standards using certified reference material, and pulp replicates. Certified reference materials demonstrate that sample assay values are accurate. Aaron Green of RPM visited the main laboratory in October 2010. |
| Verification of sampling and assaying |
The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. Discuss any adjustment to assay data. |
RPM has not independently verified significant intersections of mineralisation. No twin holes have been drilled. RPM has recommended a twin hole drilling program to provide further confidence in mineralisation continuity. Primary data is entered on hardcopies in the field and then entered digitally using Log Chief Software (Maxwell GeoServices). This data is then directly imported into the PRU central database (DataShed/Maxwell GeoServices). Historically, data was entered onto hardcopy sheets and then transcribed in Excel tables, |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| checked for accuracy, and then imported into the master Access database. Assay values that were below detection limit were adjusted to equal half of the detection limit value. Intervals with no samples were left blank in the database (updated from the -9 value used byPRU). |
||
| Location of data points |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. |
Prior to 2012, a local grid, including baseline, was established at Edikan by Cluff Plc using qualified surveyors. Qualified surveyors were used to locate all drill collars in local grid co- ordinates. For recent drill programs, collars have been located in UTM, WGS84, Zone 30N co-ordinates and transformed to local grid. True azimuths were converted to local by subtracting 43 from the true value. Local RL elevations were adjusted by adding 1,000m to avoid negative values. This was not done for the previous resource estimates. PRU drill holes are surveyed down hole at 10m to 50m intervals using either Reflex or Flexit multi-shot equipment. Historical RC holes have not been down hole surveyed and are assumed to be straight. The average depth of these holes is 94m. Historical diamond holes were down hole surveyed using either acid tubes or a single shot camera. The topographic surface used was a 2010 regional surface with localisedpit survey points. |
| Data spacing and distribution |
Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied. |
The dominant drill hole spacing is 40m by 40m. 20m by 20m spacing is used in one zone. The mineralised domains have demonstrated sufficient continuity in both geological and grade continuity to support the definition of Mineral Resource, and the classifications applied under the 2012 JORC Code. Samples have been composited to 1m lengths using best fit techniques. Two residual sample lengths were excluded. |
| Orientation of data in relation to geological structure |
Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. |
Drill holes are angled to grid south, which is approximately perpendicular to the orientation of the mineralised trends. No orientation based sampling bias has been identified in the data. |
| Sample security | The measures taken to ensure sample security. |
Chain of custody is managed by PRU. Samples are stored on site and collected by Intertek and ALS employees. PRU employees have no further involvement in the preparation or analysis of the samples. |
| Audits or reviews |
The results of any audits or reviews of sampling techniques and data. |
A review of sampling techniques was carried out on each site visit by RPM the most recent in 2010. |
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Section 2 Reporting of Exploration Results
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Mineral tenement and land tenure status |
Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The security of the tenure held at the time of reporting along with any known impediments to obtaining a license to operate in the area. |
The deposit is located within the Nanankaw Mining Lease ML1110/1994 which is wholly owned by PRU. The tenements are in good standing. The Mining Lease is valid until December 30, 2024. |
| Exploration done by other parties |
Acknowledgment and appraisal of exploration by other parties. |
Previous companies to have held the ground include Cluff Mining and Ashanti Goldfields, exploration activities included RC and Diamond drilling. |
| Geology | Deposit type, geological setting and style of mineralisation. |
The Edikan deposits occur near the western flank of the Ashanti Greenstone Belt along the Obuasi-Akropong gold corridor. The Central Ashanti property is underlain principally by Paleoproterozoic Birimian metasediments of the Kumasi-Afema basin, positioned between the Ashanti and Sefwi Greenstone Belts. The flysch type metasediments consist of dacitic volcaniclastics, greywackes plus argillaceous (phyllitic) sediments, intensely folded, faulted and metamorphosed to upper greenschist facies. Minor cherty and manganiferous exhalative sediments are locally present, and graphitic schists coincide with the principal shear (thrust) zones. Numerous small Basin-type or Cape Coast-type granitoids have intruded the sediments along several regional structures. Gold mineralisation has been identified within the same granite as that observed at the neighbouring AAF deposit. The Mampong zones are situated along the SW extension of the AAF granite. Mineralisation at Mampong has also been observed within a granite dyke 300m to the south of the main granite. |
| Drill hole information |
A summary of all information material to the under-standing of the exploration results including a tabulation of the following information for all Material drill holes: easting and northing of the drill hole collar elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar dip and azimuth of the hole down hole length and interception depth hole length If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. |
Drill hole locations are shown on the map within the body of this Mineral Resource report. Significant drill hole intersections have been previously reported to the ASX. In the opinion of PRU all material drill results have been adequately reported. |
| Data aggregation |
In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and |
Exploration drill results have been previously reported by PRU. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| methods | cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. The assumptions used for any reporting of metal equivalent values should be clearly stated. |
No aggregation of intercepts was carried out. Drilling intervals are predominantly even 1m, or composites of 2m or 4m. Mineralised composites are re-split to 1m for re-assay. Metal equivalent values are not being reported. |
| Relationship between mineralisation widths and intercept lengths |
These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g.’down hole length, true width not known’). |
Drill holes are angled to local grid which is approximately perpendicular to the orientation of the mineralised trend. |
| Diagrams | Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. |
• A plan showing Mampong drilling is included within this Mineral Resource report. |
| Balanced Reporting |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. |
Drill holes have been accurately located by PRU surveyors using the local grid system. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Other substantive exploration data |
Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. |
Resource infill drilling has progressed over as the size and extent of the mineralisation became clear. |
| Further work | The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large- scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. |
Infill resource drilling is planned within the next year to upgrade ‘in-pit’ portions of the current Mineral Resource. Along strike and down dip lode extensions have been highlighted in the body of this Mineral Resource report. |
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Section 3 Estimation and Reporting of Mineral Resources
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Database integrity |
Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. Data validation procedures used. |
The data base is systematically audited by PRU geologists. All drill logs are validated digitally by the database geologist once assay results are returned from the laboratory. In 2010, RUL reviewed the logging of several holes and validated the records in the database against the drill core and logging boards. No significant errors were noted. RPM validated the 2013 data against previous data from the 2009 estimate. No discrepancies were found. RPM also performed data audits in Surpac. |
| Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. |
Site visits have been conducted by David Price (RUL) in January 2007, Paul Payne (RUL) in January 2008, and Aaron Green (RPM) in October 2010. On each occasion, the deposit area, the core logging and sampling facility, and drilling and sampling operations were viewed. Aaron Green inspected the main laboratory used by PRU. Notes and photos were taken. Discussions were held with site personnel regarding drilling and sampling procedures. No major issues were encountered. |
| Geological interpretation |
Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. |
The confidence in the geological interpretation is considered to be good and is based on good quality drilling. The deposit consists of granite lodes of varying geometry all striking generally east-west. Extensional drilling has defined mineralisation zones along strike from the 2009 interpretation. The current interpretation is considered robust. Outcropping of mineralisation and host rocks within artisanal pits confirm the geometry of the mineralisation. Infill drilling has confirmed geological and grade continuity. |
| Dimensions | The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. |
The Mampong resource area extends over a strike length of 1,750m from 23,520mE to 25,270mN and includes the 195m vertical interval from surface at 1,175mRL to 980mRL. |
| Estimation and modelling techniques |
The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. |
Using parameters derived from modelled variograms, Ordinary Kriging (OK) was used to estimate average block grades within all domains. Surpac software was used for the estimations. High grade cuts ranging between 10g/t to 30g/t were applied to selected domains and based on statistical analysis. A total of 12 samples were cut. The parent block dimensions used were 5m NS by 20m EW by 10m vertical with sub-cells of 1.25m by 5m by 2.5m. The parent block size was selected on the basis of being approximately 50% of the average drill hole spacing in the deposit. RPM has completed two Mineral Resource |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. The assumptions made regarding recovery of by- products. Estimation of deleterious elements or other non- grade variables of economic significance (eg sulphur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation was used to control the resource estimates. Discussion of basis for using or not using grade cutting or capping. |
estimates for the deposit since 2009. The 2013 update was based on the estimate from 2009. No assumptions have been made regarding recovery of by-products. No estimation of deleterious elements was carried out. Only Au was interpolated into the block model. An orientated ‘ellipsoid’ search was used to select data and was based on parameters taken from the variography (granite domain only). For the sediment domain, the search ellipse was orientated based on observed lode geometry. Three passes were used for each domain. The first pass used a range of 60m, with a minimum of 10 samples. For the second pass, the range was extended to 120m, with a minimum of 6 samples. For the final pass, the range was extended to 240m, with a minimum of 2 samples. A maximum of 40 samples was used for all 3 passes Selective mining units were not modelled in the Mineral Resource model. The block size used in the model was based on drill sample spacing and lode orientation. Only Au assay data was available, therefore correlation analysis was not possible. The deposit mineralisation was constrained by wireframes constructed using a 0.2g/t Au cut-off grade in association with logged lithology codes. The wireframes were applied as hard boundaries in the estimate. Statistical analysis was carried out on data from 9 lodes. The high coefficient of variation and the scattering of high grade values observed on the histogram for some of the lodes suggested that top cuts were required if linear grade interpolation was to be carried out. As a result high grade cuts ranging between 10g/t to 30g/t were applied to selected domains, resulting in a total of 12 samples being cut. A three step process was used to validate the model. A qualitative assessment was completed by slicing sections through the block model in positions coincident with drilling. A quantitative assessment of the estimate was completed by comparing the average Au grades of the composite file input against the Au block model output for all the resource objects. A trend analysis was completed by comparing the interpolated blocks to the sample composite data within the granite domain. This analysis was completed for 20m eastings and 10m bench heights. Validation plots showed good correlation between the composite grades and the block model grades. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. |
||
| Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. |
Tonnages and grades were estimated on a dry in situ basis. No moisture values were reviewed. |
| Cut-off parameters |
The basis of the adopted cut-off grade(s) or quality parameters applied. |
The Mineral Resource has been reported at a 0.4g/t Au cut-off based on assumptions about economic cut-off grades for open pit mining. PRU are currently mining adjacent deposits within the Edikan Project area. |
| Mining factors or assumptions |
Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. |
RPM has assumed that the deposit could potentially be mined using open pit techniques. |
| Metallurgical factors or assumptions |
The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. |
Extensive metallurgical test-work was completed on material from a number of deposits within Edikan Project area, by AMMTEC Pty Ltd in Perth for Cluff Plc in the early 1990’s. This focused on CIL test-work on both oxide and sulphide material and later to heap leach. Preliminary amalgamation and cyanidation results using bottle roll methodology confirmed the free milling nature of both the oxide and granite mineralisation. No metallurgical testwork specific to Mampong has been completed by PRU however metallurgical test-work was undertaken by PRU in 2011 as part of the DFS for the adjacent deposits. |
| Environmental factors or assumptions |
Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. |
The Project is not subject to any environmental liabilities except for a progressive decommissioning and reclamation plan for the closed Ayanfuri heap leach mine. |
| Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, thefrequency |
Bulk density values were originally determined at the nearby AAF deposit from direct measurement of 738 diamond core samples of |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. |
which 360 were conducted in-house by PRU and 378 completed by commercial laboratories. A recent study by PRU determined that the current density assigned to fresh granite was likely too high. This assumption was based on a better understanding of the granite lodes from open pit mining activities which suggested the material should be less dense than originally expected. A program of submitting existing drill core for analysis was instigated in early 2014. A total of 254 grab samples from the open pit and 261 core samples were sent to commercial laboratories for analysis. A total of 130 core samples were sent to Intertek, and 131 core samples and all the grab samples sent to ALS. Results suggested the fresh granite material had a density in the order of 2.7t/m3 and this has been assigned to this material type in the current RPM block model. Measurements were determined by wax coating samples and immersing in water. RPM recommends an ongoing program of submitting grab samples to Intertek for analysis. Suitable core samples from any future diamond drilling programs should be selectively sent for analysis. |
|
| Classification | The basis for the classification of the Mineral Resources into varying confidence categories. Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). Whether the result appropriately reflects the Competent Person’s view of the deposit. |
The Mineral Resource was classified as Inferred Mineral Resource based on data quality, drill hole spacing, and continuity of the interpreted zones. The data quality is good and the drill spacing was mostly 40m by 40m however grade variability within many of the mineralised zones is high and continuity has not been verified. The input data is comprehensive in its coverage of the mineralisation and does not favour or misrepresent in-situ mineralisation. The definition of mineralised zones is based on high level geological understanding producing a robust model of mineralised domains. This model has been confirmed by infill drilling which supported the interpretation. Validation of the block model shows good correlation of the input data to the estimated grades. The Mineral Resource estimate appropriately reflects the view of the Competent Person. |
| Audits or reviews |
The results of any audits or reviews of Mineral Resource estimates. |
Internal audits have been completed by RPM which verified the technical inputs, methodology, parameters and results of the estimate. |
| Discussion of relative accuracy/ confidence |
Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical |
The Mampong Mineral Resource estimate has been reported with a moderate degree of confidence. The lode geometry and continuity has been interpreted to reflect the applied level of Inferred Mineral Resource. The data quality is |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. |
good and the drill holes have detailed logs produced by qualified geologists. A recognised laboratory has been used for all analyses. The Mineral Resource statement relates to global estimates of tonnes and grade. The deposit has not been mined. |
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ATTACHMENT 9
Dadieso Deposit
JORC Code (2012) Table 1
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Section 1 Sampling Techniques and Data
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Sampling techniques |
Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. |
Drill holes included in the resource were sampled using Reverse Circulation (RC) and diamond drill (DD) holes on a nominal 40m by 40m grid spacing (with localised areas of 20m by 20m). A total of 160 holes were included in the resource for a total 3,295m within the resource wireframes. Holes were generally angled at 50° towards grid west or east to optimally intersect the mineralised zones. Drill hole collars were picked up and down hole surveyed by qualified surveyors. RC samples were collected by a riffle splitter at 1m to 2m intervals. Diamond core was cut in half using a core saw with sampling at geological boundaries. All samples were collected from the same side of the core. Sampling and QAQC procedures were carried out to industry standards. Samples from the first 60 RC drill holes were sent to Transworld Laboratory for 24hr bottle roll with AAS finish. All subsequent RC samples were analysed by 50g Fire Assay at ALS Kumasi. Diamond half core samples analysed by 50g Fire Assay and AAS finish. |
| Drilling techniques |
Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face- sampling bit or other type, whether core is oriented and if so, by what method, etc). |
RC drilling comprising 105mm diameter face sampling bit. Diamond drilling carried out with HQ2 and NQ2 sized equipment. |
| Drill sample recovery |
Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. |
Recoveries from historical drilling are unknown. Actual recoveries from PRU diamond drilling are recorded in the main Edikan database and average 96% with no significant issues noted. No actual recoveries were included in the data supplied for the Dadieso deposit. RC samples were visually checked for recovery, moisture and contamination. |
| Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. |
All holes were field logged by company geologists. Weathering, lithology, alteration, structure, mineralogy and veining information were recorded. RC chips are glued to boards as a visual reference of every hole. Logging of diamond core also recorded recovery, core strength, orientation, roughness, and infill type. Diamond core was photographed. All drill holes were logged in full. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The total length and percentage of the relevant intersections logged. |
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| Sub-sampling techniques and sample preparation |
If core, whether cut or sawn and whether quarter, half or all core taken. If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub- sampling stages to maximise representivity of samples. Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Whether sample sizes are appropriate to the grain size of the material being sampled. |
HQ2 and NQ2 core was cut in half using a core saw. All samples were collected from the same side of the core. RC samples were collected at the rig using riffle splitters. Samples were predominantly dry. Less than 0.5% of samples were recorded as ‘wet’ in the supplied data in the ‘sampquality’ field, although 55% of records in this field are blank. Sampling of diamond core and RC chips uses industry standard techniques. After drying the sample is subject to a primary crush, then pulverised so that 90% passes a -75um sieve. Field QC procedures involved the use of certified reference materials (1 in 20), and field duplicates (1 in 20). Field duplicates were taken on 1m to 2m composites for RC using a riffle splitter. Sample sizes are considered appropriate to correctly represent the moderately nuggetty gold mineralisation based on: the style of mineralisation, the thickness and consistency of the intersections, the sampling methodology and assay value ranges for Au. |
| Quality of assay data and laboratory tests |
The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established. |
The analytical techniques used Fire Assay on 50g samples or BLEG bottle roll on 1kg samples both with AAS finish. This method approaches total dissolution of most minerals. No geophysical tools were used to determine any element concentrations used in this resource estimate. Sample preparation checks for fineness were carried out by the laboratory as part of internal procedures to ensure the grind size of 90% passing 75µm was being attained. Laboratory QAQC includes the use of internal standards using certified reference material, and pulp replicates. Certified reference materials demonstrate that sample assay values are accurate. Aaron Green of RPM visited the main laboratory in October 2010. |
| Verification of sampling and assaying |
The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. Discuss any adjustment to assay data. |
RPM has not independently verified significant intersections of mineralisation. DKRC067 and DKRC068 are twinned holes and display similar down hole grades. The east and west dipping holes on 40m spacing result in ‘crossing’ of drill traces at depth. Primary data is entered on hardcopies in the field and then entered digitally using Log Chief Software (Maxwell GeoServices). This data is then directly imported into the PRU central database (DataShed/Maxwell GeoServices). Assay values that were below detection limit were adjusted to equal half of the detection limit value. Intervals with no samples were left blank in the database (updated from the -9 value used byPRU). |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Location of data points |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. |
Prior to 2012, a local grid, including baseline, was established at Edikan by Plc (Cluff) using qualified surveyors. Qualified surveyors were used to locate all drill collars in local grid co- ordinates. For recent drill programs, collars have been located in UTM, WGS84, Zone 30N co-ordinates and transformed to local grid. True azimuths were converted to local by subtracting 43 from the true value. Local RL elevations were adjusted by adding 1,000m to avoid negative values. This was not done for the previous resource estimates. PRU drill holes are surveyed down hole at 10m to 30m intervals using either Reflex or Flexit multi-shot equipment. Historical RC holes have not been down hole surveyed and are assumed to be straight. The average depth of these holes is 50m. Topographic surface based on 1,181 historic pit survey points and 1,955 topographic and drill hole surveyed locations byPRU surveyors. |
| Data spacing and distribution |
Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied. |
The nominal drill hole spacing is 40m by 40m. The mineralised domains have demonstrated sufficient continuity in both geological and grade continuity to support the definition of Mineral Resource, and the classifications applied under the 2012 JORC Code. Samples have been composited to 2m lengths using best fit techniques. One residual sample length was excluded. |
| Orientation of data in relation to geological structure |
Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. |
Drill holes are angled to grid east and west, which is approximately perpendicular to the orientation of the interpreted mineralised trends. No orientation based sampling bias has been identified in the data. |
| Sample security | The measures taken to ensure sample security. |
Chain of custody is managed by PRU. Samples are stored on site and collected by Intertek employees. PRU employees have no further involvement in the preparation or analysis of the samples. |
| Audits or reviews |
The results of any audits or reviews of sampling techniques and data. |
A review of sampling techniques was carried out on each site visit by RPM the most recent in 2010. |
Section 2 Reporting of Exploration Results
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Mineral tenement and land tenure status |
Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The security of the tenure held at the time of |
The deposit is located within the Dadieso Prospecting Licence PL6/15, which expired on 31 December 2013 and was wholly owned by PRU. An application for renewal has been made with no known impediment as to the grant of a renewal or as to future grant of a mining lease. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| reporting along with any known impediments to obtaining a license to operate in the area. |
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| Exploration done by other parties |
Acknowledgment and appraisal of exploration by other parties. |
Previous companies to have held the ground include Cluff Mining and Ashanti Goldfields. Exploration activities included RC and Diamond drilling. |
| Geology | Deposit type, geological setting and style of mineralisation. |
The Edikan deposits occur near the western flank of the Ashanti Greenstone Belt along the Obuasi-Akropong gold corridor. The Central Ashanti property is underlain principally by Paleoproterozoic Birimian metasediments of the Kumasi-Afema basin, positioned between the Ashanti and Sefwi Greenstone Belts. The flysch type metasediments consist of dacitic volcaniclastics, greywackes plus argillaceous (phyllitic) sediments, intensely folded, faulted and metamorphosed to upper greenschist facies. Minor cherty and manganiferous exhalative sediments are locally present, and graphitic schists coincide with the principal shear (thrust) zones. Numerous small Basin-type or Cape Coast-type granitoids have intruded the sediments along several regional structures. Gold mineralisation has been identified within, or is associated with, the margins of a granitoid intrusive which has intruded into a sequence of metasediments. Mineralisation is typically 20- 120m wide and remains open at depth. Mineralisation is associated with minor quartz veining and sulphides which are predominantly pyrite. |
| Drill hole information |
A summary of all information material to the under-standing of the exploration results including a tabulation of the following information for all Material drill holes: easting and northing of the drill hole collar elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar dip and azimuth of the hole down hole length and interception depth hole length If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. |
Exploration results are not being reported. Drill hole locations are shown on the map within the body of this Mineral Resource report. Significant drill hole intersections have been previously reported to the ASX. In the opinion of PRU all material drill results have been adequately reported. |
| Data aggregation methods |
In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. |
Exploration drill results are not being reported. No aggregation of intercepts was carried out. Drilling intervals are predominantly even 1m, or composites of 2m or 4m. Mineralised composites are re-split to 1m for re-assay. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| The assumptions used for any reporting of metal equivalent values should be clearly stated. |
Metal equivalent values are not being reported. |
|
| Relationship between mineralisation widths and intercept lengths |
These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g.’down hole length, true width not known’). |
Drill holes are angled to local grid which is approximately perpendicular to the orientation of the mineralised trend. |
| Diagrams | Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. |
Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Balanced Reporting |
Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. |
Drill holes have been accurately located by PRU surveyors using the local grid system. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
| Other substantive exploration data |
Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. |
No other substantive work other than RC drilling has been conducted at the deposit. |
| Further work | The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large- scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. |
No further work is currently planned at the deposit. Exploration results have been previously reported to the ASX and are not being reported for this Mineral Resource update. |
Section 3 Estimation and Reporting of Mineral Resources
| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Database integrity |
Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. Data validation procedures used. |
The data base is systematically audited by PRU geologists. All drill logs are validated digitally by the database geologist once assay results are returned from the laboratory. In 2010, RUL reviewed the logging of several holes and validated the records in the database against the drill core and logging boards. No significant errors were noted. RPM validated the 2013 data against previous data from the 2009 estimate. RPM alsoperformed data audits in Surpac. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. |
Site visits have been conducted by David Price (RUL) in January 2007, Paul Payne (RUL) in January 2008, and Aaron Green (RPM) in October 2010. The Dadieso deposit was not visited during any of these visits as it was considered to be an early stage exploration project. On each occasion, the core logging and sampling facility, and drilling and sampling operations were viewed. Aaron Green inspected the main laboratory used by PRU. Notes and photos were taken. Discussions were held with site personnel regarding drilling and sampling procedures. No major issues were encountered. |
| Geological interpretation |
Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. |
The confidence in the geological interpretation is considered to be moderate. The deposit consists of steeply dipping mineralised lodes. Infill drilling has supported the model at localised areas although continuity remains poor along the majority of some lodes. Outcropping of mineralisation (evident from extensive shallow workings from Artesial miners) confirms the geometry of the mineralisation to a degree. Infill drilling has confirmed geological and grade continuity in localised areas. |
| Dimensions | The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. |
The Dadieso resource area extends over a strike length of 890m (from -10,030mN to -9,140mN), and includes the 200m vertical interval from 1,170mRL to 970mRL. The overall plan width of the mineralised lodes is 300m and extends from -400mE to -50mE. |
| Estimation and modelling techniques |
The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. The assumptions made regarding recovery of by- products. Estimation of deleterious elements or other non- grade variables of economic significance (eg sulphur for acid mine drainage characterisation). In the case of block model interpolation, the block size in relation to the average sample spacing and the search employed. |
Using parameters derived from modeled variograms, Ordinary Kriging (OK) was used to estimate average block grades within the lodes. Surpac software was used for the estimations. A high grade cut of 20g/t was applied to all lodes with the exception of Objects 14 and 24 where a high grade cut of 10g/t was applied. A total of 10 samples were cut. The parent block dimensions used were 10m NS by 10m EW by 10m vertical with sub-cells of 2.5m by 2.5m by 2.5m. The parent block size was selected on the basis of being approximately 50% of the average drill hole spacing in the deposit. No previous mining has occurred at the deposit (with the exception of Artesial mining where production is unknown). No estimation of deleterious elements was carried out. Only Au was interpolated into the block model. An orientated ‘ellipsoid’ search was used to select data and was based on parameters taken from the variographyand orientated to |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Any assumptions behind modelling of selective mining units. Any assumptions about correlation between variables. Description of how the geological interpretation was used to control the resource estimates. Discussion of basis for using or not using grade cutting or capping. The process of validation, the checking process used, the comparison of model data to drill hole data, and use of reconciliation data if available. |
individual lode geometry. Three passes were used for each domain. The first pass used a range of 50m, with a minimum of 10 samples. For the second pass, the range was extended to 100m, with a minimum of 6 samples. For the final pass, the range was extended to 250m, with a minimum of 2 samples. A maximum of 40 samples was used for all 3 passes. No assumptions were made on selective mining units. Only Au assay data was available, therefore correlation analysis was not possible. The deposit mineralisation was constrained by wireframes constructed using a 0.2g/t Au cut-off grade in association with logged lithology codes. The wireframes were applied as hard boundaries in the estimate. A three step process was used to validate the model. A qualitative assessment was completed by slicing sections through the block model in positions coincident with drilling. A quantitative assessment of the estimate was completed by comparing the average Au grades of the composite file input against the Au block model output for all the resource objects. A trend analysis was completed by comparing the interpolated blocks to the sample composite data for the combined lodes. This analysis was completed for 40m northings and 10m bench heights. Validation plots showed good correlation between the composite grades and the block model grades. |
|
| Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. |
Tonnages and grades were estimated on a dry in situ basis. No moisture values were reviewed. |
| Cut-off parameters |
The basis of the adopted cut-off grade(s) or quality parameters applied. |
The Mineral Resource has been reported at a 0.4g/t Au cut-off based on assumptions about economic cut-off grades for open pit mining. PRU are currently mining adjacent deposits within the Edikan Project area. |
| Mining factors or assumptions |
Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. |
RPM has assumed that the deposit could potentially be mined using open pit techniques. |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Metallurgical factors or assumptions |
The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. |
Extensive metallurgical testwork was completed on material from a number of deposits within Edikan Project area, by AMMTEC Pty Ltd in Perth for Cluff Plc in the early 1990’s. This focussed on CIL testwork on both oxide and sulphide material and later to heap leach. Preliminary amalgamation and cyanidation results using bottle roll methodology confirmed the free milling nature of both the oxide and granite mineralisation. Metallurgical testwork was undertaken by PRU in 2011 aspart of the DFS. |
| Environmental factors or assumptions |
Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. |
The Project is not subject to any environmental liabilities except for a progressive decommissioning and reclamation plan for the closed Ayanfuri heap leach mine. |
| Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. The bulk density for bulk material must have been measured by methods that adequately account for void spaces (vugs, porosity, etc), moisture and differences between rock and alteration zones within the deposit. Discuss assumptions for bulk density estimates used in the evaluation process of the different materials. |
A total of 956 bulk density determinations have been undertaken at the Edikan Project. 814 samples were from primary rock, 48 were from slightly weathered to strongly weathered material, and 94 were from the transitional zone, which is a fair reflection on the proportion of sulphide Mineral Resources to oxide Mineral Resources. The bulk density of the mineralisation has been determined with a high degree of confidence from extensive sampling and measurements, however additional samples specifically from Dadieso should be taken in future drilling programs. |
| Classification | The basis for the classification of the Mineral Resources into varying confidence categories. |
Mineral Resources were classified in accordance with the Australasian Code for the Reporting of Identified Mineral Resources and Ore Reserves (JORC, 2012). The deposit was classified as Inferred Mineral Resource based on data quality, drill hole spacing, and continuity of mineralisation. Recent infill drilling at the deposit has reduced the predominantly 40m by 40m spaced drill centres to 20m by 20m in some areas, however, the continuity of grade is poor and detailed controls on the mineralisation are poorly understood. The input data is adequate in its coverage of the mineralisation and does not favour or misrepresent in-situ mineralisation. Infill drilling has confirmed the mineralisation continuity for the main lodes and support the interpretation. Validation of the block model shows good correlation of the input data to the estimated grades. The Mineral Resource estimate appropriately |
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| Criteria | JORC Code explanation | Commentary |
|---|---|---|
| Whether appropriate account has been taken of all relevant factors (ie relative confidence in tonnage/grade estimations, reliability of input data, confidence in continuity of geology and metal values, quality, quantity and distribution of the data). Whether the result appropriately reflects the Competent Person’s view of the deposit. |
reflects the view of the Competent Person. | |
| Audits or reviews |
The results of any audits or reviews of Mineral Resource estimates. |
Internal audits have been completed by RPM which verified the technical inputs, methodology, parameters and results of the estimate. |
| Discussion of relative accuracy/ confidence |
Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. The statement should specify whether it relates to global or local estimates, and, if local, state the relevant tonnages, which should be relevant to technical and economic evaluation. Documentation should include assumptions made and the procedures used. These statements of relative accuracy and confidence of the estimate should be compared with production data, where available. |
The relative accuracy of the Mineral Resource estimate is reflected in the reporting of the Mineral Resource as per the guidelines of the 2012 JORC Code. The Mineral Resource statement relates to global estimates of tonnes and grade. The deposit is not currently being mined. |
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