Extract Resources - Resource upgrade establishes Rössing South as the 6th
largest global uranium deposit
/NOT FOR DISTRIBUTION TO UNITED STATES NEWSWIRE SERVICES OR FOR DISSEMINATION IN THE UNITED STATES/
Highlights:
- Resource upgrade moves Rössing South into the top 6 global uranium
deposits by contained metal.
- Zones 1 and 2 Indicated Resource increased to more than a quarter of
a billion pounds (257M.lbs) U3O8: a ten-fold increase in
Indicated Resource from the previous resource statement (ASX release
22nd July 2009).
- Inferred Resource of 110M.lbs U3O8, including Maiden Inferred
Resource from Zones 3 and 4.
- 37% increase in Total Resource size from previous resource statement
(ASX release 22nd July 2009).
- Confirmed as the largest in-situ and highest grade granite-hosted
uranium deposit in Namibia.
- Extensive exploration potential within Husab Uranium Project still to
be tested with an extensive drilling program continuing.
- Resource now defined to support completion of Definitive Feasibility
Study (DFS).
SYDNEY NSW, AUSTRALIA, Aug. 11 /CNW/ - Extract Resources Limited (ASX/TSX/NSX: EXT) ("Extract" or "the Company") today announces a new resource estimate, following JORC Code and Canadian NI43-101 guidelines, for the Rössing South Deposit, part of Extract's Husab Uranium Project in Namibia.
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Rössing South Resource Tonnes Grade U3O8
Classification (Mt) (ppm U3O8) (Mlb)
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Zones 1 + 2 Indicated 241.0 480 257.0
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Zones 1 + 2
+ 3 + 4 Inferred 125.5 400 110.3
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Note: Figures have been rounded and are reported above a lower cut of
100ppm U3O8.
The size and grade of the new resource confirms Rössing South as one of the most significant uranium discoveries made in the last decade, and establishes it as the largest in-situ and highest grade, granite-hosted uranium deposit in Namibia. The increased resource underpins the Company's next milestone, which is the completion of the Definitive Feasibility Study ("DFS"), and takes Extract another step forward from a successful explorer to becoming a major uranium producer.
High resource grades at Zones 1 and 2 have been maintained since the previous resource statement (ASX release 22nd July 2009), confirming that the drilling adequately defines the inherent grade distribution and continuity within the deposits.
Figure 1 highlights the rapid progress the Company has made since early 2008 in advancing the resource inventory to underwrite the definition of reserves and, in due course, support the development of a long-life mining operation at the Husab Uranium Project.
Since July 2009, the drilling effort has been successful in both the conversion of resources from Inferred to Indicated status and growing the resources in Zones 1, 2, 3 and 4. Indicated and Inferred Resources (Total Resource) grew by approximately 37% for all four zones. Indicated Resources now account for 70% of the Total Resource.
To view Figure 1 - Rössing South Resource Evolution & Growth please visit: http://files.newswire.ca/814/xtract0811.pdf
Extract's Managing Director, Jonathan Leslie, said: "The resource upgrade at Rössing South is a significant step forward for the Company and for the Husab Uranium Project. We have further defined one of the world's largest uranium resources which supports the scheduled completion of the Definitive Feasibility Study in Q4 2010 and, in time, the development of a world-class mine.
"We also expect that the resource base will continue to increase with on-going drilling. Once in full production, the Husab Uranium Mine is expected to become the second largest producer in the world.
Mr Leslie also added, "The immediate priority remains completing the Definitive Feasibility Study on Zones 1 and 2 to bring these deposits into production within the shortest possible time frame. Seventeen drill rigs remain on site with the current focus on completing the drilling required to define Measured Resources within the Zones 1 and 2 starter pits.
"Once the resource update has been optimised additional drilling will be planned, aimed at converting additional Inferred Resource material to Indicated status and defining additional resources down plunge of high grade domains. An updated resource is expected within Q1 2011.
"Significant exploration potential remains to be tested throughout the Husab Uranium Project, with 7 of the 15 kilometre Rössing South trend yet to be drilled. Although Extract's priority remains resource definition and project development, exploration of this large mineralised system is expected to continue for some time."
The Company looks forward to providing further updates as the full potential of the Husab Uranium Project continues to be realised.
About Extract Resources
Extract Resources Ltd is an international uranium exploration and development company whose primary focus is in Namibia. The company's principal asset is its 100%-owned Husab Uranium Project which contains two known uranium deposit areas, Rössing South and Ida Dome. Extensive exploration potential also exists for new uranium discoveries in the region. Extract Resources is listed on the Australian (ASX), Toronto (TSX) and Namibian (NSX) Stock Exchanges.
RÖSSING SOUTH - RESOURCE UPDATE DETAILS
A summary of the resource estimation methodology follows. All figures are shown relative to a projection of UTM WGS 84 Zone 33 South.
Deposit Geology
The Husab Project is located within the central Damara Orogenic Belt ('DOB') in a zone characterised by basement domes, regional folding, faulting, and late Damaran intrusive rocks.
The Husab Project is dominated by a series of north-northeast to northeast trending regional-scale antiforms and synforms, which make up the main structural architecture of the entire Central Zone of the Damara. These meta-sedimentary folds or dome-like structures of the DOB are cored by gneissic and metasedimentary rocks of the Abbabis Formation. The basement rocks are covered to the northeast and south by stranded cover sequences of flat-lying calcrete and alluvial deposits, which are associated with a broad northeast trending valley marginal to the Khan River.
The Rössing South prospect represents a 15 kilometre target zone, most of which is covered by the Namib Desert (eolian sand and gravels) with the prospective target zone defined by the magnetic trend that can be verified in outcrop and then traced beneath the desert sands. Extract have confirmed the potential of the prospective stratigraphic trend, defined by the magnetic data, to host uraniferous granite (alaskite). Drilling completed to date at Rössing South has followed a zone of uraniferous alaskites that crop out at the northern end of EPL 3138 and trend southwards under cover for a distance of approximately eight kilometres. The mineralised alaskites are associated with calc-silicate, metasediments, gneiss and biotite schist lithologies of the Khan, Rössing and Chuos Formations. The Rössing Formation is the dominant host into which the passive uraniferous granites have intruded.
Resource Database
The drillhole database in the immediate vicinity of the estimation consists of 185 diamond drillholes (74,109m) and 890 RC (263,655m) drillholes which have all been drilled by Extract since 2008. The drillholes were typically drilled towards the west (WGS84/33S grid) with a dip of -60degrees to -70degrees.
The resource database contains a combination of chemical assaying (255,376 samples - 99.7%) and factored downhole gamma radiometric data (654, 1m composites - 0.3%) which were used to define the mineralised zones used for estimation. Approximately 23,100 individual samples were used directly in the resource estimate for Zone 1 and 16,500 for Zones 2 to 4. The Extract QAQC data was reviewed and showed appropriate levels of precision and accuracy.
Bulk density was applied to the Resource model based upon the rock Formation rock type and alaskite lithology. The average bulk density for the mineralised zones in Zone 1 was 2.68t/m(3) and between 2.68t/m(3) and 2.70t/m(3) for Zones 2 to 4. These values were chosen after analysis of the 4,026 selected bulk density samples obtained by Extract using the water immersion method.
The Extract drillhole samples are prepared by Genalysis Laboratory Services in Johannesburg and analysed in Perth by Genalysis Laboratory Services, both reputable laboratories. The samples were analysed for uranium by Inductively Coupled Plasma Mass Spectrometry (ICPMS) after multi-acid digest and by XRF pressed pellet.
The down-hole radiometric data was sourced from a downhole GRS42 spectrometer tool. Based upon a comparison of matching chemical and radiometric data, the original radiometric eU3O8 grades were factored using a linear regression. The resulting factored eU3O8 grades were considered appropriate for the use in the resource estimation.
Geological Modelling
To establish appropriate grade continuity, the mineralisation model for the Rössing South deposits was based upon a nominal 75 ppm U3O8 cut-off. The mineralisation constraints were generated based upon sectional interpretation and three dimensional analyses of the available drilling data. The main lithological and stratigraphic contacts (e.g. alaskite, sediments and other lithotypes) were considered at the time of modelling and used to guide modelling of mineralisation shapes. Unless a strong geological model could be established, mineralised zones which did not have more than two drillhole intersections on two consecutive sections were not included in the estimates.
The Rössing South - Zone 1 region (Figure 2 and 3) was modelled as 42 distinct zones (3m to 145m thickness, averaging 23m) with a NE trend. Individual zones were modelled to extend for up to 1,100 m along strike and between 100m to 450m down-dip. Due to the geometries of the mineralisation, the true thickness of the mineralisation ranges from 80% to 100% of the down hole thickness. Figure 6 shows a typical sectional interpretation with the drillholes coloured by assay grade.
The Rössing South - Zone 2 region (Figure 2 and 4) was modelled as 29 distinct zones (3m to 82m thickness, averaging 19m) with a NE trend. Individual zones were modelled to extend for up to 1,200 m along strike and between 100m to 600m down-dip. Due to the geometries of the mineralisation, the true thickness of the mineralisation ranges from 80% to 100% of the down hole thickness. Figure 7 shows a typical sectional interpretation with the drillholes coloured by assay grade.
The Rössing South - Zones 3 and 4 regions (Figure 2 and 5) were modelled as eight distinct zones (3m to 79m thickness, averaging 16m) with a NE trend. Individual zones were modelled to extend for up to 1,300 m along strike and between 100m to 400m down-dip. Due to the geometries of the mineralisation, the true thickness of the mineralisation ranges from 80% to 100% of the down hole thickness. Figure 8 shows a typical sectional interpretation with the drillholes coloured by assay grade.
To view Figures 1 through 8 please visit: http://files.newswire.ca/814/xtract0811.pdf
Grade Estimation
The data captured within the mineralisation model was composited to a 3m downhole composite length. Based on the 3m composite data, a statistical and geostatistical investigation was completed to derive appropriate estimation parameters such as high-grade cuts, variogram model parameters, and search ranges. High grade cuts were used to limit the undue influence of high-grade outliers. High-grade cuts ranging from of 2,000ppm to 6,000ppm U3O8 were applied to the data with a typical decrease in mean grade of 4%.
Grade estimation was undertaken using two, three dimensional block models (Zone 1 and Zones 2-4). A parent block size of 25m N by 25m E by 15m RL was selected as the appropriate block size for each of the block models based on the current average data spacing and the geostatistical investigations completed. The modelled zones are well defined by the existing drilling. Grade was estimated using both Surpac and Datamine Mining software, with the results combined into a final model using Datamine.
Ordinary Kriging (`OK') was chosen as the appropriate method for estimating grade using the cut 3m composites. An anisotropic variogram model was used as inputs into the estimation based upon analysis of each of the regions being estimated. A three pass estimation regime was used with only data from the respective mineralised zones. Resource Categorisation of the grade estimate was undertaken on the basis of the criteria laid out in the JORC Code (2004) and the Canadian National Instrument 43-101 ("CNI43-101"). Indicated and Inferred Resources were defined using the criteria determined during the validation of the grade estimates, with detailed consideration of the CNI43-101 categorisation guidelines.
Blocks were classified as Indicated based upon regions which had well established geological continuity and a nominal data spacing of 50m by 50m to 50m by 100m. Blocks not classified as Indicated and which had a reasonable geological continuity and a data spacing of 100m by 100m to 100m by 200m were classified as Inferred.
No mining has been undertaken at Rössing South to date.
The competent persons for the resource statement are Messrs Inwood and Le Brun.
The reported resource for the Rössing South deposit, reported above selected cut-offs to a depth of 500m, is summarised below. The preferred cut-off for reporting resources is 100ppm U3O8.
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Table 1:
Rössing South - August 6th 2010 Resource Estimate
Reported at various cut-offs, Preferred cut-off: 100ppm U3O8
Ordinary Kriged Estimate based upon 3m cut U3O8 Composites
Parent Cell Dimensions of 25m NS by 25m EW by 15m RL
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Lower Contained Contained
Cut Off Tonnage Grade U3O8 U3O8
(ppm U3O8) (Mt) (ppm U3O8) (MKg) (MLb)
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Zone 1
Indicated
100 122.2 450 55.0 120.1
200 104.5 490 51.2 113.9
300 78.0 580 45.3 99.3
400 56.2 670 37.6 82.6
Inferred
100 41.3 420 17.4 37.8
200 34.2 470 16.1 35.2
300 24.7 550 13.6 29.9
400 17.0 640 10.9 24.1
Zone 2
Indicated
100 118.8 520 61.8 136.9
200 110.0 550 60.5 133.7
300 87.7 630 55.3 121.2
400 66.3 720 47.8 104.8
Inferred
100 26.8 520 13.9 30.5
200 24.5 550 13.5 29.7
300 19.3 630 12.1 26.8
400 14.1 740 10.4 22.9
Zone 3
Inferred
100 43.0 250 10.7 24.0
200 24.3 330 8.0 17.5
300 11.8 410 4.9 10.7
400 4.3 530 2.3 5.0
Zone 4
Inferred
100 14.4 570 8.2 17.9
200 13.0 610 7.9 17.5
300 11.4 660 7.5 16.6
400 9.0 740 6.7 14.7
All Zones
Indicated
100 241.0 480 117 257.0
200 214.5 520 112 247.6
300 165.7 610 101 220.6
400 122.5 700 85 187.4
Inferred
100 125.5 400 50 110.3
200 96.1 470 45 99.9
300 67.2 570 38 84.0
400 44.4 680 30 66.7
The Company also has an existing resource defined at the Ida Dome deposits (ASX release 7th August 2008), approximately 20 kilometres south of Rössing South. Resource details are shown in the following table.
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Table 2:
Ida Dome - 7th August 2008 Resource Estimate
Reported at a 100 ppm U3O8 cut-off
Figures have been rounded.
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Lower Contained Contained
Cut Off Tonnage Grade U3O8 U3O8
(ppm U3O8) (Mt) (ppm U3O8) (MKg) (MLb)
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Ida Dome Deposits (Garnet Valley, New Camp and Ida Central)
Indicated
100 0.6 246 0.14 0.31
200 0.5 259 0.12 0.26
Inferred
100 52.7 213 11.25 24.80
200 27.0 261 7.08 15.60
The information in this report that relates to Exploration on the Husab Project is based on information compiled or reviewed by Mr Martin Spivey, who is a Member of The Australasian Institute of Mining and Metallurgy and Mr Andrew Penkethman who is a Member of the Australian Institute of Geoscientists. Mr Spivey and Mr Penkethman are both full time employees of the Company. Mr Spivey and Mr Penkethman have sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which they are undertaking to qualify as a Competent Person as defined in the 2004 Edition of the `Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'. Mr Spivey and Mr Penkethman consent to the inclusion in this report of the matters based on their information in the form and context in which it appears.
Information in this report relating to Mineral Resources is based on information compiled or reviewed by Mr Neil Inwood and Mr Steven Le Brun. Mr Inwood is a Principal Resource Consultant and Mr Le Brun a Specialist Resource Consultant with Coffey Mining Pty Ltd, (independent resource consultants engaged by Extract Resources Limited). Mr Inwood and Mr Le Brun are members of The Australasian Institute of Mining and Metallurgy. Both Mr Inwood and Mr Le Brun have sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which they are undertaking to qualify as a Competent Person under the JORC Code. Mr Inwood and Mr Le Brun consent to the inclusion of the data in the form and context in which it appears.
Reference to down hole spectrometer results in this announcement refers to data collected by consulting geophysical contractor Terratec Geophysical Services undertaking down hole logging with a Gamma Ray Spectrometer (GRS42). This unit was calibrated at the Pelindaba facility in South Africa before arriving on site. The uranium values are recorded as parts per million (ppm) eU3O8 which is equivalent to ppm U3O8. Whilst results from this unit provide an indication of uranium mineralisation present they may also be affected by uranium mobility and disequilibrium. These factors should be considered when interpreting eU information while waiting for confirmation chemical assay results.
Reference to hand held spectrometer results refers to use of a Company owned Exploranium, GR-135 Plus or Terraplus RS-125, hand held spectrometer. The uranium values are recorded by placing the unit on the bulk RC sample bags or individual trays of drill core and expressed as parts per million (ppm) eU which is equivalent to ppm U. Results from these units provide an indication of uranium mineralisation; they may also be affected by uranium mobility and disequilibrium. These factors should be considered when interpreting eU information whilst waiting for confirmation chemical assay results.
This press release contains forward-looking statements based on current expectations. These forward-looking statements entail various risks and uncertainties that could cause actual results to differ materially from those reflected.
For further information: please visit www.extractresources.com or contact: Extract Resources: London Office, Jonathan Leslie, Chief Executive Officer/Managing Director, Tel: +44 (0)20 7317 9220, [email protected]; Extract Resources: Perth Office, Andrew Penkethman, Manager Projects, Siobhan Lancaster, Company Secretary, Tel: +61 89 367 2111, [email protected], [email protected]; Brunswick Group (UK), Carole Cable, Pip Green, Tel: +44 (0)20 7404 5959; MAGNUS Investor Relations/Corporate Communication (Australia), John Gardner, Tel: +61 (0)2 9286 0260, Mob: +61 (0)413 355 997
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