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BRIGHTSTAR RESOURCES LIMITED — Capital/Financing Update 2009
Feb 4, 2009
64581_rns_2009-02-04_df3e6849-5ca0-4c84-9ab1-a1203fb01b76.pdf
Capital/Financing Update
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AUSTRALIAN STOCK
EXCHANGE CODE AAM
Current Issued Capital: 108,541,861 Ordinary Fully Paid Shares Market Cap at 10 cents $ 10.1M Cash at Bank: $3.0M
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- 5 February 2009
ASX ANNOUNCEMENT
NEW DELTA GOLD RESOURCE ESTIMATE
Key Points:
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Maiden Resource for the Delta Gold Discovery 725,000oz
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Adding 70% Increase for BrightStar Gold Project
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Consolidated Resources for BrightStar now more than 1.7Moz
A1 Minerals is pleased to announce a 725,000oz gold resource for the new Delta discovery. The Consolidated resources for the BrightStar Gold Project have now increased 70% from 1.01Moz (reported ASX Announcement 6/6/2007 and 2/10/2008) to 1.7Moz.
DELTA 725,000oz
Suite 34, 25 Walters Drive, Osborne Park WA 6017 Telephone (618) 9244 1400 Facsimile (618) 9244 1600 Email [email protected] Website www.a1minerals.com.au
ABN 44 100 727 491
Table 1: Mineral Resource Statement
| CATEGORY | A. 0-100m 0.5g/t lowercut | A. 0-100m 0.5g/t lowercut | A. 0-100m 0.5g/t lowercut | B. >100m 1g/t lowercut | B. >100m 1g/t lowercut | B. >100m 1g/t lowercut | A+B | A+B | A+B |
|---|---|---|---|---|---|---|---|---|---|
| Tonnes (1000) |
Grade g/t |
Ounces | Tonnes (x1000) |
Grade g/t |
Ounces | Tonnes (X1000) |
Grade g/t |
Ounces | |
| Indicated | 2,976.9 | 1.99 | 190,075 |
1,175.2 | 3.19 | 115,320 | 4,152.1 | 2.29 | 305,395 |
| Inferred | 478.9 | 2.85 | 43,915 | 2,925.0 | 4.00 | 376,164 | 3,403.9 | 3.84 | 420,079 |
| TOTAL | 3,455.8 | 2.11 | 233,990 |
4,100.2 | 3.77 | 491,484 | 7,556.0 | 2.99 | 725,474 |
NOTE: Some rounding occurs when estimating tonnes leading to variances which may be observed between the various total figures.
Appendix 1: Notes Relating to JORC Statement
Drill Sampling Techniques:
The JORC Resource estimate has been based on drilling by RC, air core and diamond methods. This includes drilling by A1 Minerals and historic drilling within the acquired database. Practices for sampling of historic drilling by other companies are not specifically documented. However the previous exploration companies involved including Ashton and Austwhim who adopted conventional standards for that time similar to those carried out by A1. Only previous RC and diamond drilling results were used in the resource estimate.
Drill Sample Recovery
Drill core and RC/air core sample recovery was high.
Logging
All holes were logged using the A1 Minerals standard logging codes and legend. Particular notice was taken of wet conditions reflecting shear zones and lithological boundaries and also quartz content. Gold results often correlated with quartz veins and shear zones. Logging included recognition of regolith and weathering boundaries as well as lithological, alteration and structural interpretation.
Sub sampling Techniques
Standard 1-metre interval samples were taken in 99% of the ore zone.
Quality of Assay and Laboratory Tests
Duplicates sampling was conducted in most cases at regular 25m sample intervals.
For drill core fire assaying with a 40gram or 50gram charge was completed initially. Screen fire assaying was conducted on 50% drill core samples at laboratories in Kalgoorlie and independently in Perth for intervals where high grade interpreted nuggetty gold had been reported in fire assay results. Screen fire results were generally similar or higher than the fire assay results. Screen Fire assaying was required because of numerous occurrences of visible gold. For all other samples most assaying was conducted at independent laboratories at Kalgoorlie and Leonora where the whole sample underwent crushing and pulverizing prior to fire assay using a 50gram charge.
Verification of Sampling and Assaying
Duplicate samples were taken a quality check on field sampling. Close spaced drilling was occasionally conducted to confirm gold intervals.
The concentration of high grades within certain areas of the deposit was evident. The high drill density in these areas alleviated any concern of high deposit variance distorting the resource estimate.
Location of Data Points
All holes surveyed by differential GPS as well as historic holes keyed in by modern survey.
Data Spacing and Distribution
Above 100metres depths most drill spacing is on a 20metre to a maximum of 40metre sectional basis and centres average of 15m to a maximum of 40 metres.
Orientation of Data in relation to Geological Structure
Drilling by A1 has utilized and infilled the existing exploration grid established by previous explorers. This orientation is orthogonal to the strike -shear related mineralization. At Delta 2 however the mineralization follows 060 shear trend oblique to the strike trend and this has been taken into account in the interpretation and estimation process.
Drill core orientation was conducted at Delta 2 to check local mineralization direction as was the production of long sections and a transform section.
Suite 34, 25 Walters Drive, Osborne Park WA 6017 Telephone (618) 9244 1400 Facsimile (618) 9244 1600 Email [email protected] Website www.a1minerals.com.au
ABN 44 100 727 491
The overall resource geometry is controlled by a northerly trending shear zone more than 3km long and variably up to 200metres wide wthin a northwest trending stratigraphy dipping 70 degrees to the east.
Hosting the gold within the shear zone are three sub-parallel sub-vertical intense shears accompanied by north easterly crosscutting faults which cause tension gashes and ore terminations. The shear zone also has oblique riedel shear hosted gold deposits
Audits or reviews of Sampling Techniques and data
Reviews conducted by A1 Minerals Ltd geologist.
Limited production records and historic data exists which reconciles with geological interpretation and grade estimations.
Database integrity
Data is stored and checked in Micromine software and related validation software. A1 Minerals Ltd employs a competent database administrator.
Geological interpretation
A1 has used historic exploration and production information, and its own geological data gathering to establish and extend gold resources with high geological confidence and with a view to gold production.
A number gold domains have been identified at Delta:
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The Cork Tree Pit operations mined gold associated with cherts, variably iron rich. There is no gold in the adjacent black shales. Deep drilling under these pits confirms the chert –gold association.
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To the north of the pits gold occurs as steep (70 degrees) easterly dipping mineralized lodes with NNW strike continuity along sheared lithological contacts, particularly metasedimentary, quartz dolerite and ultramafic boundaries. Up to three such sub parallel lodes exist on many sections.
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A second association of gold is in a large flat- lying shallow palaeochannel immediately beneath lateritic clays between the pits and Delta2. This occurrence has a quartz/ iron association.
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Highest grade gold is associated with structural links between sheared horizons. The mineralization is strongest at Delta 2 where the north south trend is intersected by 060 cross structures evident from magnetics and gravity survey analysis. Significant interpretation of mineralization was conducted on hard copy Micromine derived cross sections and long sections. Outlines to 0.2g/ t Au have been digitized into Micromine.
Mineralization varies from flat lying shallow palaeochannel to steep east dipping mineralized lodes, with up to three parallel lodes existing. Cross-cutting and linking structures enhance gold mineralisation. Important mineralization controls were:-
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Quartz veining
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Shearing
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Silica, carbonate and pyrite alteration
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Lithological boundaries
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Chert /BIF and dolerite
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Ferruginous zone(‘palaeochannel’ gold)
Dimensions
The Delta resource extends for almost 3.2kms in strike and comprises several gold domains within a NNW trending shear zone up to 200 metres wide. Depth of high grade gold mineralisation appears beyond 300m depth. However resources are limited to this depth because of sparcity of drill data. More drilling at these depths and beyond should increase and upgrade the resource.
Estimation Method and modelling
A polygonal method of estimation was based on the interpretation of 20 metre spaced geological sections over the entire 3.2km length of the Delta gold mineralized zone.
Bulk density
A bulk density of 2.2 was applied for oxide and 2.4 for transition.
For palaeochannel gold an SG of 1.8 was applied. Deep drilling in fresh rock used 2.6 SG consistent with that for fresh sedimentary rock. These figures are considered realistic possibly conservative for the fresh material and palaeochannel gold.
Oxidation Boundaries
Oxidation boundaries were determined from logging and later digitized into the model. These were also considered in the geological interpretation and manual estimate. Base of completely oxidized rock (BOCO) and base of oxidation (BOX) were interpreted and strings produced in Micromine. Base of laterite and lateritic clay was also logged as well as base of upper saprolite. Nominally lithologies were completely oxidised to between 20m and 40m depths, though up to almost 60m of weathered upper saprolite was noted in the palaeochannel area. Rocks were partially weathered to 60 to 80m, marking the top of fresh rock.
Cut Off grades
Suite 34, 25 Walters Drive, Osborne Park WA 6017 Telephone (618) 9244 1400 Facsimile (618) 9244 1600 Email [email protected] Website www.a1minerals.com.au
ABN 44 100 727 491
Above 100m depth a 0.5g/t lower cut was applied. Of note is this lower cut off provides an average resource grade very similar to the historic mined grade. Beneath 100m depth a lower cut off grade of 1g/t was used. An 80g/t Au top cut was been used.
Classification
Drill spacing and geological confidence was considered sufficiently high that the drilled resource area is all in Indicated category under JORC Code, with the exception of the Central zone which is Inferred.
Mining Factors
The lower cut off of 0.5g/t Au used considered the following: -Lower mining costs due to soft weathered rocks. -Relatively low strip ratio likely to apply to any open pit
-Reduced capital costs due to existing infrastructure. -Current high gold prices
Metallurgical testing
Metallurgical test work and previous production history indicate the ore is free milling and extracted by conventional CIP process. Extraction test work has determined that total gold recoveries are similar across the different deposits for fresh and transitional material and average greater than 95%.
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Figure. 1 Sub-vertical Chert ore averages 4 g/t between the yellow paint marks. The remnant chert ore is in the Saddle Zone between the Cork Tree Well pits.
Suite 34, 25 Walters Drive, Osborne Park WA 6017 Telephone (618) 9244 1400 Facsimile (618) 9244 1600 Email [email protected] Website www.a1minerals.com.au
ABN 44 100 727 491
BACKGROUND INFORMATION
A1 MINERALS LIMITED is developing the BrightStar Gold Project in the prospective Laverton gold district of Western Australia. Planning and development is underway to commence gold production this year.
A1 Minerals has its own CIP treatment plant which is planned to sited at Delta prospect. Delta has existing mining infrastructure and is close (35kms) to the Laverton township with service and accommodation facilities.
A1 Minerals initially expects to start producing gold at a rate of 30,000oz per annum. Cash costs are expected to be US$ 420/oz.
For more information please contact John Williams on 61 8 9244 1400 or visit the Company’s web site at www.a1minerals.com.au
John Williams Managing Director
The information in this report that relates to Exploration Results or Mineral Resources is based on data compiled by Mr Tony Ryall who is a Member of the Australasian Institute of Mining and Metallurgy. Mr Ryall is a independent consulting geologist and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity undertaken to qualify as Competent Persons as defined in the 2004 Edition of the “Australian Code for Reporting of Mineral Resources and Ore Reserves”. Mr Ryall has consented to the inclusion in this report of the matters based on information in the form and context in which it appears.
Suite 34, 25 Walters Drive, Osborne Park WA 6017 Telephone (618) 9244 1400 Facsimile (618) 9244 1600 Email [email protected] Website www.a1minerals.com.au
ABN 44 100 727 491