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IGO LIMITED Capital/Financing Update 2018

Dec 19, 2018

65111_rns_2018-12-19_7ce2188c-be9f-4a16-b476-f10bacd88252.pdf

Capital/Financing Update

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20 December 2018

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PRE-FEASIBILITY STUDY CONFIRMS POTENTIAL FOR UNDERGROUND MINE AT TROPICANA

Independence Group NL (IGO or the Company) (ASX:IGO) is pleased to announce that a prefeasibility study into the development of an underground mine beneath the Boston Shaker pits at Tropicana (the Pre-Feasibility Study or PFS) has confirmed that underground mining is technically and financially viable. The PFS is based on the scheduling of underground Mineral Resources with robust economics, fully integrated with the open pit mining plan.

The Tropicana joint venture partners, AngloGold Ashanti Australia Ltd (AGAA) and IGO (AGAA 70% and manager, IGO 30%) are now progressing a Feasibility Study (FS). The completion of this FS and a financial commitment to the Boston Shaker underground development is expected in the second half of FY19.

Boston Shaker PFS Highlights

  • The PFS has confirmed that the development of an underground mine at Boston Shaker is technically and financially viable within a nominal PFS level of accuracy (+/- 25%).

  • The study confirmed the technical feasibility and potential viability of an underground mine delivering ~1Mtpa of resources to produce in the order of 100,000 ounces per annum over a life-of-mine of approximately 7 years based on mine scheduling of the Boston Shaker underground Indicated and Inferred Mineral Resource only.

  • The project would require an estimated capital investment of A$95 million.

  • The joint venture partners, IGO and AGAA, are now progressing a FS, which is expected to be completed in the second half of FY19.

  • The underground operation will be aligned with the open pit design and schedule, capitalising on process plant improvements delivered in late November 2018 through the successful commissioning of the second ball mill.

  • The positive PFS results has led to the commitment to additional drilling, as part of the FS, to define Ore Reserves.

IGO’s Managing Director, Peter Bradford, commented: “The Pre-Feasibility Study demonstrates the potential viability of underground mining beneath the Boston Shaker open pits that integrates with the existing open pit life-of-mine. Delivery of Boston Shaker underground will result in an improved grade and gold production profile from Tropicana from FY21.

“The Pre-Feasibility Study is one of a number of work programs implemented at Tropicana to add value. The results are extremely encouraging, and we look forward to completing the feasibility study and potentially starting another exciting chapter at Tropicana.”

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Mineral Resource

The Boston Shaker Underground Mineral Resource is reported within a limiting wireframe defined by a profit algorithm to remove isolated and lower grade material, focused on material above a 1.8g/t cut-off grade, and based on a gold price of A$1,778/oz (US$1,400/oz). The Boston Shaker underground Mineral Resource (at 100%) is shown in the table below:

Table 1: Boston Shaker Underground Mineral Resource

Classification Mt Au g/t Au Moz
Measured 0.0 0.0 0.00
Indicated 3.1 4.0 0.40
Inferred 7.5 4.3 1.05
Total 10.6 4.2 1.45

The current Boston Shaker Underground Mineral Resource has been classified as Indicated and Inferred. Infill drilling to convert Inferred Resources to Indicated Resources is ongoing, with an update to the Mineral Resource estimate and the public reporting of an underground Ore Reserve expected in late 3Q19 as part of the FS. The total drill metres informing the PFS Mineral Resource model is 1,436 holes for 175,000m. The drilling has been completed on both a 100m x 100m and 50m x 25m centres. Further infill drilling was completed during October and November 2018, for a total of 16,098 metres drilled. Recent highlights from this program are illustrated on Figure 1 and include:

  • BSD166 16m at 5.37g/t from 470m

  • BSD170 19m at 4.37g/t from 489m

  • BSD171: 22m @ 4.68g/t from 453m

  • BSD172: 9m @ 7.66g/t from 464m, and 12m at 3.76g/t from 477m

  • BSD173: 15m @ 4.12g/t from 456m

  • BSD174: 12m @ 4.14g/t from 454m

  • BSD178: 19m @ 5.87g/t from 452m

Full details of the drill-hole intercepts are included in Appendix A.

Boston Shaker Underground Mining Strategy

The ground conditions at Boston Shaker are good and conventional ground support systems and practices have been incorporated into the PFS. The Boston Shaker underground mine design is based on conventional Long Hole Open Stoping, using longitudinal retreat and transverse stoping sequences. The underground mine design is schematically represented in Figure 2.

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Figure 1: Boston Shaker Drilling Results for drilling completed in October and November 2018 (Looking north-west)

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Tropicana Pit Boston Shaker Pit
Tropicana access portal
Boston Shaker PFS Underground Layout
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Figure 2: Boston Shaker Open Pit, Underground Development and access link to Tropicana

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The underground mine design targets a production rate of 1Mtpa of material grading 3.7g/t to produce in the order of 100,000oz per annum over a life-of-mine of up to seven years. This mine life is subject to the conversion of the underground Inferred Resources into Indicated Resources which is currently being executed as part of the FS. The initial portal development is anticipated to start from within the completed Tropicana pit in mid-2019. Full production levels should be reached in 2021, with the last stopes currently scheduled to be mined in 2026. Underground material will be blended with open pit ore and processed in the existing mill. Interfaces between the Boston Shaker underground mine and the open pit mining activities have been incorporated into the 2019 business plan.

It should be noted that the resource remains open at depth and will be further explored during the life-of-mine.

Ore Processing

The metallurgical testwork completed as part of the PFS indicates that the current processing circuit is suitable to treat the underground material. The current throughput rate of 8.1Mtpa will be maintained. Metallurgical recovery remains in the 88-90% range with no adverse effect expected on reagent consumption and/or the processing cost.

Infrastructure

All infrastructure requirements to establish an underground mine have been scoped as part of the PFS. This includes an expansion to the mine village, additional Emergency Response facilities, workshops, power transmission lines and additional power generation capacity, as well as ventilation requirements.

Capital Cost

The capital cost is estimated at A$95 million (incl. mining development) in real terms on a 100% basis and at a Pre-Feasibility level of accuracy (+/- 25%).

Table 2: Boston Shaker Underground Project – Capital Cost

Major Area 2019 2020
A$M
Total
A$M
A$M
Feasibility 4 - 4
Mining development 22 29 51
Infrastructure - Surface 17 6 23
Infrastructure - Mining 2 6 8
Indirects 5 2 6
Contingency 3 1 4
Total Capex 52 43 95

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Operating Costs

The Boston Shaker operating costs estimated for the PFS (+/- 25%) are shown in the table below:

Table 3: Boston Shaker Underground Project – Operating Cost

Major Area Costs
A$/t
Mining 80
Processing 19
G&A 3
Total Operating Costs 102

Second Ball Mill

The second 6MW ball mill was successfully commissioned in late November 2018. The second ball mill will increase the total throughput rate by about 5% and gold recovery will be improved by up to 3% to approximately 92% at a grind of 65 microns. The operation now has the flexibility to vary the grind size to manage the trade-off between throughput and recovery. The project has been executed on time for a total expected cost of A$36 million (100% basis).

Continued Value Enhancement

The Boston Shaker underground mine is an exciting opportunity for Tropicana and is aligned to the continuous improvement culture of the mine. The FS is in progress and the outcome is expected towards the end of 3Q19.

COMPETENT PERSON STATEMENT

The information that relates to Exploration Results and Mineral Resources was based on information compiled by Mr. Damon Elder, a full-time employee and security holder of AngloGold Ashanti Australia Limited, who is a member of The Australasian Institute of Mining and Metallurgy. Mr. Elder has sufficient experience relevant to the type and style of mineral deposits under consideration, and to the activity which has been undertaken, to qualify as a Competent Person as defined in the 2012 edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’ (the JORC Code). Mr. Elder consented to the release of the Mineral Resource estimate, based on the information in the form and context in which it appears.

FORWARD LOOKING STATEMENTS

This announcement contains forward-looking statements regarding future events, conditions and circumstances including but not limited to statements regarding plans, strategies and objectives of management, anticipated timelines and expected costs and levels of production. Often, but not always, forward-looking statements can be identified by the use of forward-looking words such as

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"may", "will", "expect", "intend", "plan", "estimate", "anticipate", "continue" and "guidance", or other similar words.

These forward-looking statements are not a guarantee of future performance and involve unknown risks and uncertainties, many of which are beyond IGO’s control, which may cause actual results and developments to differ materially from those expressed or implied. These risks include but are not limited to economic conditions, stock market fluctuations, commodity demand and price movements, access to infrastructure, timing of approvals, regulatory risks, operational risks, reliance on key personnel, reserve and resource estimations, native title and title risks, foreign currency fluctuations, exploration risk and mining development, construction and commissioning risk.

A portion of the production target referred to in this announcement is based on Inferred Mineral Resources. There is a low level of geological confidence associated with Inferred Mineral Resources and there is no certainty that further exploration work will result in the determination of Indicated Mineral Resources or that the production target itself will be realised.

Forward-looking statements in this announcement apply only at the date of issue. Subject to any continuing obligations under applicable law or regulations, IGO does not undertake to publicly update or revise any of the forward-looking statements in this announcement or to advise of any change in events, conditions or circumstances on which any such statement is based. Readers are cautioned not to place undue reliance on any forward-looking statements contained in this announcement.

Peter Bradford Managing Director & CEO Independence Group NL +61 8 9238 8300 [email protected]

Jill Thomas Communications Manager Independence Group NL +61 8 9238 8300

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APPENDIX A – DRILL-HOLE INTERCEPT DETAILS

Table 4: Boston Shaker Underground Project – Drill Hole Intercept Details

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APPENDIX B – JORC CODE TABLE 1 – TROPICANA GOLD MINE

Section 1: Sampling Techniques and Data – Boston Shaker PFS

Criteria Commentary
Sampling techniques
 AngloGold Ashanti Australia Ltd. (AGAA) has used drilling and subsampling of the cuttings or cores
as the data basis for the Mineral Resource estimates of the Boston Shaker underground deposit.
Details are given in the following subsection.
 Drill hole spacings range from 12mNx12mE (grade control) in the depleted Boston Shaker (BS01)
open pit to 100m×100m grids at depth.
 All holes are drilled plunging towards the west to intersect the east dipping mineralised zones.
Drilling techniques
 Reverse circulation (RC) percussion drilling using face-sampling bits (5¼ inch or 133mm diameter)
has been used to collect samples from the shallower (up-dip) part of the deposits with a nominal
maximum RC depth of 150m.
 Diamond core drilling has been used for deeper holes, with diamond tails drilled from RC pre-collars.
To control the deviation of deep DD holes drilled since 2011, many of these holes were drilled from
short60m RC pre-collars or using 63.5mm (HQ) diameter core from surface.
 Diamond core drilling for Mineral Resource definition is predominantly 47.6mm (NQ) diameter core,
with a lesser number of holes drilled for collection of metallurgical and/or geotechnical data using
63.5mm (HQ2, HQ3) ore 85mm (PQ) core diameters.
 In fresh rock, cores are oriented wherever possible for collection of structural data. Prior to 2009,
core orientations are made using the EzyMark tool with the Reflex Ace Tool replacing the system in
later drilling programmes.
Drill sample recovery
 RC recovery:
oPrior to 2008 semi-quantitative assessment was made regarding RC sample recovery with
recovery visually estimated as 25%, 50%, 75% or 100% of the expected mass volume of a 1m
drilling interval.
oSince 2008, AGAA has implemented quantitative measure on every 25th interval where the
masses of the sample splits are recorded and compared to the theoretical mass of the sampling
interval for the rock type being drilled.
oAGAA found that overall recovery in the regolith was >80% and total recovery in fresh rock.
 DD Recovery:
oDD recovery has been measured as percentage of the total length of core recovered compared
to the drill interval.
oCore recovery is consistently high in fresh rock with minor losses occurring in heavily fractured
ground or for DD drilling in the regolith.
 The main methods to maximise recovery have been recovery monitoring as described above and
diamond core drilling below150m depth.
 No relationships have been noted between sample recovery and grade and sample biases that may
have occurred due to the preferential loss or gain of fine or course material are considered unlikely.
Logging
 RC cuttings and DD cores have been logged geologically and geotechnically with reference to
AGAA’s logging standard library, to levels of detail that support Mineral Resource estimation,
Underground Ore Reserve estimation and metallurgical studies.
 Qualitative logging includes codes for lithology, regolith, and mineralisation for both RC and DD, with
sample quality data recorded for RC such as moisture, recovery, and sub-sampling methods.
 DD cores are photographed, qualitatively structurally logged with reference to orientation
measurements where available.
 Geotechnical quantitative logging includes QSI, RQD, matrix and fracture characterisation.
 The total lengths of all drill holes have been logged.
Sub-sampling techniques
and sample preparation
 RC – Primary splitting
oPrior to 2007 RC samples were collected from the cyclone stream using a tiered riffle splitter.
From 2007 a static cone splitter was introduced and replaced riffles splitters on all rigs.
  • The RC sampling interval is generally 1m but from 2016, 2m intervals were introduced for RC pre-collars.

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Section 1: Sampling Techniques and Data – Boston Shaker PFS

Criteria Commentary
oThe splitters collected a12% split from the primary lot with two 12% splits collected – the first for
laboratory submission and second as a reference or replicate. Most samples were collected dry
with <2% of samples recorded as being split in moist or wet state.
oThe main protocol to ensure the RC samples were representative of the material being collected
was monitoring of sample recovery and collection and assay of replicate samples.
 DD – Primary sample
oDD cores are collected of intervals determined by geological boundaries but generally targeting a
1m length.
oAll NQ cores have been half-core sampled with the core cut longitudinally with a wet diamond
blade.
oA few of the DD whole cores have been sampled from HQ3 cores drilled to twin RC holes in the
regolith or for geotechnical or metallurgical testing.
oIn 2005, some 1,150m of cores drilled in the oxide zone were chisel split rather than wet cut but
this poorer sub-sampling represents <0.01% of the core drilled.
 Laboratory preparation
oSample preparation has taken place at three laboratories since commencement of Mineral
Resource definition drilling including SGS Perth (pre- 2006), Genalysis Perth (2006 to April 2016)
and Tropicana site laboratory (2015 Boston Shaker samples and post-April 2016 samples).
oRC samples were over dried then pulped in a mixer mill to a PSD of 90% passing 75 microns
before subsampling for fire assay.
oSGS prepared DD half-core samples by jaw-crushing then pulverisation of the whole crushed lot
to a particle size distribution (PSD) of 90% passing 75 microns. A 50g subsample of the pulp was
then collected for fire assay.
oGenalysis prepared the samples in a Boyd crusher rotary splitter combo with nominally 2.5kg
half-core lots crushed to <3mm then rotary split to1 kg before pulverisation and sub-sampling
for fire assay.
oSamples less with mass <800g submitted to Tropicana laboratory are pulped in a LM2 mill to a
PSD of 75 microns before sub-sampling for fire assay. Samples with larger masses are crushed
in a Boyd crusher to a PSD of 90% passing 2mm then subsampled using a linear sample divider.
oFrom May 2016, a jaw crusher has been used to crush half-core samples to a PSD of 100%
passing 6mm.
 Quality controls for representativity
oSGS inserted blanks and standards at a 1:20 frequency in every batch with a duplicate pulp
collected for assay every 20th sample. Further repeats were also completed at a 1:20 frequency
in a random manner.
oSieve checks were completed on 5% of samples to monitor PSD compliance.
oGenalysis inserted blanks and standards in every batch and a duplicate pulp was collected for
assay on every 25th sample and 6% of each batch was randomly selected for replicate analysis.
Sieve checks were completed on 5% of samples to monitor PSD compliance.
oTropicana laboratory used barren basalt and quartz to clean equipment between routine
samples.
 Sample size versus grain size
oNo specific heterogeneity tests have been carried out but the sample sizes collected are
consistent with industry standards for the style of mineralisation under consideration.
oA 2008 sampling variability study found that 72% of the gold in the samples tested was in size
fraction <300 microns, and that repeated sampling of the same lot have very low variance
between replicates.
Quality of assay data and
laboratory tests
 No geophysical tools were used to determine any element concentrations material to the Mineral
Resource estimate.
 All Mineral Resource prepared pulps have undergone 50g fire assay which is considered a total
assay for gold.
 As discussed above all laboratories have used industry standard quality control procedures with
standards used to monitor accuracy, replicate assay to monitor precision, blanks to monitor potential
cross contamination and sieve tests to monitor PSD compliance.
 AGAA has also used other ‘umpire’ laboratories to monitor accuracy including Genalysis Perth (prior
to November 2006), SGS (from November 2006 to August 2007) and ALS Perth (since August 2007),
with these check assaying campaigns coinciding with each Mineral Resource update.
 AGAA has reviewed the quality sample results on a batch by batch and monthly basis and has found
that the overall performance of the laboratories used for Mineral Resource estimation samples is
satisfactory.

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Section 1: Sampling Techniques and Data – Boston Shaker PFS

Criteria Commentary
Verification of sampling
and assaying
 Significant intersections of mineralisation are routinely verified by AGAA senior geological staff and
have also been inspected by several independent auditors as describe further below.
 Twin holes have been drilled to compare results from RC and DD drilling with the DD results
confirming that there is no material down-hole smearing of grades in the nearby RC drilling and
sampling.
 All logging and sample number data is captured digitally in the field using Field Marshall Software
(upgrade to Micromine Geobank in 2016). Data is downloaded daily to the Tropicana exploration
server and checked for accuracy, completeness and structure by the field personnel.
 Assay data is merged electronically from the laboratories into a central Datashed database, with
information verified spatially in Vulcan software. AGAA maintains standard work procedures for all
data management steps.
 An assay importing protocol has been set up to ensure quality samples are checked and accepted
before data can be loaded into the assay database.
 All electronic data is routine backed up to AGAA’s server in Perth and provided to IGO via FTP
transfer.
 There have been no adjustments or scaling of assay data other than setting below detection limit
values to half detection for Mineral Resource estimation work.
Location of data points
 All completed drill-hole collar locations of surface holes have been using RTK GPS equipment, which
was connected to the state survey mark (SSM) network.
 The grid system is GDA94 Zone 51 using AHD elevation datum.
 Prior to 2007, drill hole path surveys have been completed on all holes using Eastman single shot
camera tools, with down-hole gyro tools used for all drilling post 2007.
 A digital terrain model was prepared by Whelan’s Surveyors from aerial photography flown in 2007,
which has been supplemented with collar data surveyed using RTK GPS. This model is considered
to have centimetre-scale accuracy.
Data spacing and
distribution
 Drill hole spacings range from 12mNx12mE (grade control) in the depleted Boston Shaker (BS01)
open pit to 100m×100m grids at depth.
 Down-hole sample intervals are typically 1m with 2m compositing applied for Mineral Resource
estimation work.
 The Competent Person considers that these data spacings are sufficient to establish the degree of
geological and grade continuity appropriate for the Mineral Resource and Underground Ore Reserve
estimation procedures applied, and the JORC Code classification applied.
Orientation of data in
relation to geological
structure
 Most drill hole are oriented to intersect the shallowly east dipping mineralisation at a high angle and
as such, a grade bias introduced by the orientation of data in relation to geological structure is highly
unlikely.
Sample security
 The chain-of-sample custody is managed by AGAA.
 Samples were collected in pre-numbered calico bags, which are then accumulated into polyweave
bags for transport from the collection site. The accumulated samples are then loaded into wooden
crates and road hauled to the respective laboratories (Perth or Tropicana).
 Sample dispatches are prepared by the field personnel using a database system linked to the drill-
hole data.
 Sample dispatch sheet are verified against samples received at the laboratory and any missing
issued such as missing samples and so on are resolved before sample preparation commences.
 The Competent Person considers that the likelihood of deliberate or accidental loss, mix-up or
contamination of samples is considered very low.
Audits or reviews
 Field quality control data and assurance procedures are review on a daily, monthly and quarterly
basis by AGAA field personnel and senior geological staff.
 The field quality control and assurance of the sampling was audited by consultant QG in 2007 and
2009. The conclusion of the audit was that the data was suitable for Mineral Resource estimation
work.

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Section 2: Reporting of Exploration Results – Boston Shaker PFS

Criteria Explanation
Mineral tenement and land
tenure status
 The Tropical Gold Mine Mineral Resources are located wholly within WA mining lease M39/1096, which
commenced on 11 Mar 2015 and has a term of 21 years (expiry 10 Mar 2036).
 Tropicana Gold Mine in a joint venture between AGAA (70%) and IGO (30%) with AGAA as manager.
 Gold production is subject to WA State royalties of 2.5% of the value of gold value.
 There are no material issues relating to native title or heritage, historical sites, wilderness or national parks, or
environmental settings.
 The tenure is secure at the time of reporting and there are no known impediments to exploitation of the Mineral
Resource and Underground Ore Reserve and on-going exploration of the mining lease.
Exploration done by other
parties
 AGAA entered in to a JV with IGO in early 2002 with the main target of interest being a WMC gold soil
anomaly of 31ppb, which was reporting in a WA government open file report. Prior to the JV, the WMC soil
sampling program was the only known exploration activity and the only dataset available were WA government
regional magnetic and gravity data.
Geology
 The Tropicana Gold Mine is on the western margin of a 700km long magnetic feature that is interpreted to the
collision suture zone between the Archean age Yilgarn Craton to the west and the Proterozoic age Albany-
Fraser Origan to the east of this feature. The gold deposits are hosted by a package of Archean age high
metamorphic grade gneissic rocks.
 Four distinct structural domains have been identified – Boston Shaker, Tropicana, Havana and Havana South,
which represent the same mineral deposit offset by NE striking faults that post-date the mineralisation.
 The gold mineralisation is hosted by a shallowly SW dipping sequence of quartz-feldspar gneisses,
amphibolites, granulites, meta-sedimentary cherts.
 The gold mineralisation is concentrated in a ‘favourable horizon’ of quartz-feldspar gneisses, with a footwall of
garnet gneiss, amphibolite or granulite.
 Mineralisation is characterised by pyrite disseminations, bands and crackle veins within altered quartz-feldspar
gneiss. Higher grades are associated with close-spaced veins and sericite alteration.
 Mineralisation presents as stacked higher grade lenses within a low-grade alteration envelope. Geological
studies suggest the mineralisation is related to shear planes that post-date the development of the main
gneissic fabric and metamorphic thermal maximum.
Drill hole Information
 A summary of the many hole used to prepare the Mineral Resource estimate is not practical for this public
report. The Mineral Resource estimate give the best-balanced view of all the drill-hole information.
Data aggregation methods
 No metal equivalent values are considered in the Mineral Resource estimate.
Relationship between
mineralisation widths and
intercept lengths
 All Mineral Resource drilling interests the mineralisation at a high angle and as such approximate true
thicknesses in most cases.
Diagrams
 IGO has included representative diagrams have been included in prior ASX public reports.
Balanced reporting
 The Mineral Resource is based on all available data and as such provides the best-balanced view of the
Boston Shaker underground Mineral Resource.
Other substantive
exploration data
 Information relating to other exploration data, such as density, metallurgical assumptions are detailed in
Section 3 further below.
Further work
 Exploration drilling is continuing the within tenement with a minor Mineral Resource update planned for early
2019.

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Section 3: Estimation and Reporting of Mineral Resources – Boston Shaker PFS

Criteria Commentary
Database integrity  AGAA captures field data and drill hole logging directly in to handheld devices or laptop computers using
Field Marshall and Geobank software.
 The drill-hole data is managed in DataShed software, which is an industry recognised system for
management of geoscientific drill hole information. Logging, assays and survey information is loaded directly
into Datashed using data import routines, with loading procedures incorporating quality control checking.
 Data is validated following loading through visual inspection of results on-screen both spatially and using
database queries and cross section plots. Typical checks carried out against original records to ensure data
accuracy include items such as overlapping records, duplicate records, missing intervals, end-of-hole checks
and so on.
Site visits  The Competent Person is site based and is actively involved in the management and supervision of the
Mineral Resource estimation.
Geological interpretation  To control the Mineral Resource estimation process, three dimensional digital solids were prepared in
LeapFrog software for the mineralised zones, dykes, shears and garnet (mostly hanging-wall) gneiss.
 Mineralised solids were prepared using a nominal 0.3g/t Au drill hole cut-off grade to encompass the gold
mineralisation targeted for Mineral Resource estimation. The dykes, shears and garnet gneiss solids were
prepared from geological logging codes. Regolith units were prepared as digital surfaces below topography
based on the geological logging.
 The resulting models encompass the mineralisation, the post-mineralisation barren dykes, the shears
controlling higher grade mineralisation and the main waste rock units that are the footwall and hangingwall to
the mineralisation.
Dimensions  The Boston Shaker underground Mineral Resource extends approximately 700m below surface and 400m
below the base of the Boston Shaker Open Pits.
Estimation and modelling  The total drill metres informing the PFS Mineral Resource model is 1,436 holes for 175,000 metres.
techniques  The estimate has been prepared using Ordinary Block Kriging in Isatis software into block dimensions
10mX×10mY×2mZ in the rotated coordinates.
 Drill hole data were composited to 2m prior to estimation with no-top cuts applied.
 There has been no mining of the Underground Resource to compare to the estimate.
 Sulphur is modelled as a secondary (independent) variable.
Moisture  The tonnages are estimated on a dry basis.
Cut-off parameters  The Underground estimate cut-off grade is based on assumptions of a pre-feasibility study completed in
2013 which used a gold price of $US1,400/tr.oz ($A1,778/tr.oz) and underground mining and process cost
assumptions for fresh Mineral Resource.
 The cut-off grade for reporting the Underground Mineral Resource on this basis is1.8 g/t Au.
Mining factors or  The assumption for the Underground Mineral Resource is long-hole open stoping between 20m levels.
assumptions  No Mineral Resource margin (extremal) dilution has been modelled in either estimate.
 The Mineral Resource is reported.
Metallurgical factors or  The ore processing method at Tropicana is well-established with conventional, crushing, grinding then
assumptions carbon-in-leach extraction of gold followed by electrowinning to produce gold bars.
 Gold recovery factors are based on extensive metallurgical testing and range from 92.5% recovery in
mineralised transported material down to 89.9% recovery in fresh rock.
Environmental factors or  Tropicana Gold mine operates under an environmental management plan that meets or exceeds all statutory
assumptions and legislative requirements.
 Mined waste rock is disposed in waste dumps which are progressively rehabilitated as mining progresses
with any potentially acid generating waste encapsulated in non-acid generating material.

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Section 3: Estimation and Reporting of Mineral Resources – Boston Shaker PFS

Criteria Commentary
 A tailing storage facility is used to contain and capture process residues.
 The mine produces rehabilitation plans for ongoing rehabilitation and mine closure plans, and the costs are
included in the financial model.
Bulk density  AGAA routinely collects in situ bulk density measurements on10cm long core segments using the
Archimedes principle method of dry weight versus weight in water. There are200,000 density
measurements in the estimation database with the vast majority (~98%) of measurements from fresh rock
and the remainder in the regolith or cover.
 Measurements are collected over 1m to 5m intervals targeting intervals that are deemed representative of
key lithologies in fresh rock. Density has been collected on core within the regolith from ‘core-from-surface’
drill holes, with the measurement method accounting for voids.
 Depending on rock type density ranges of 1.89 t/m3 to 2.18 t/m3 in the saprolite and ranges from 2.56t/m3 to
2.96 t/m3 in the transitional and fresh rock domains.
 Density is estimated by ordinary block kriging in the Mineral Resource estimates apart from a few minor
domains with sparse data (such as the regolith), where density is assigned as a mean of the data.
Classification  The basis of classification of the Boston Shaker underground estimates into different JORC Code confidence
categories is drill hole spacing as follows:
oMeasured Mineral Resources: average 12.5mE×12.5mN collar spacing
oIndicated Mineral Resources: average 25mE×50mN collar spacing
oInferred Mineral Resources: average 100mE×100mN collar spacing (or less) when evidence of
geological or grade continuity is sufficient to support grade estimation
 AGAA considers that the Measured Resource support mine planning with a 90% confidence interval of ±15%
on tonnage or grade on a quarterly production basis, with Indicated Resources have the same confidence
but applicable on an annual production basis.
 The Competent Person considers this classification takes in to account all relevant factors such as data
reliability, confidence in the continuity of geology and grades, and the quality, quantity and distribution of the
data.
Audits or reviews  The Open Pit estimate methodology was audited by consultant QG in 2007, 2009 and 2011.
 Consultants Golder Associates audited the 2015 estimate in 2015.
 Consultants Optiro reviewed and endorsed the Mineral Resource Estimate in November 2017.
 AGAA also conducts internal peer reviews on the completion of estimate updates.
Relative  AGAA has carried out some conditional simulation studies to confirm the relationship between drill spacing
Accuracy/Confidence and 90% confidence interval assumptions and found the study results in agreement with the drill spacing
classification criteria described above.
 Mine reconciliation for the life-of-mine to date is satisfactory.

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