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Projects
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Uranium Resource
On 15 September 2008 Eleckra announced its maiden uranium mineral resource estimate for the Thatcher Soak uranium deposit located within Eleckra’s Yamarna Project. Independent consultants Coffey Mining have estimated an Inferred Mineral Resource at Thatcher Soak of 16.1 million tonnes averaging 174ppm U3O8 for 6.2 million pounds of contained U3O8 (or approximately 2,800 tonnes contained U3O8) using a 100ppm U3O8 cut-off. Eleckra’s Thatcher Soak uranium project is located approximately 150km north-east of Laverton in Western Australia within granted exploration licences E38/1083 and E38/1388 to which Eleckra holds a 100% interest and within the Yamarna pastoral lease owned by Eleckra. The mineralisation extends to the west into Uranex NL’s tenements (Figure 1). The Thatcher Soak uranium mineralisation is principally carnotite with the mineralised zones elongated parallel to the drainage and largely coincident with a playa lake system. The mineralisation is usually shallow and 1m to 2m thick. The resource was estimated using Ordinary Kriging of geochemical and factored radiometric assays within wireframes that formed the constraints for the block model constructed by Coffey Mining. Radiometric density readings were taken by downhole probe on 60 drill-holes from the most recent program. These density values were reduced below the water table to give a figure for the dry density. The density used to report the resource (1.97t/m3) was based upon the mean of the dry factored radiometric density readings.
A total of 814 vertical aircore drill-holes are present in the Eleckra database, of which 810 were used in the resource modelling. The average depth of the holes is 9.6m, with 83.4% of the holes being less than 10m in depth. The holes are drilled on a regular 100m EW by 200m NS grid with some infill drilling at 100m NS. There were two phases of drilling. In the first phase holes were sampled by gamma probe as well as being chemically assayed throughout. The second phase holes were sampled by gamma probe and only partially chemically assayed. The resource estimate is based predominantly on the chemical assays. Where these have not been taken, the gamma value has been used after factoring by 90% (in these cases the downhole position of the gamma intersection has been accepted). The mineralisation zone interpretation was constructed based on a nominal 100ppm U3O8 drill-hole grade. The mineralised zones are relatively flat and less than 5m thick. Up to 3 zones may be present at any one section. Statistical analyses on the 1m U3O8 composites were completed prior to estimation. Variography was conducted as input into grade estimation. Top cuts were selected based on an assessment of distribution statistics, including frequency distribution plots and ranked grade charts. Top cuts resulted in a lowering of the mean grade in Domains 1, 2, and 10 (the largest domains) by 1.9%, 14.7%, and 0.5% respectively. The method used to obtain the U3O8 grade estimates was Ordinary Kriging using the cut 1m U3O8 composites. Parent cell dimensions of 100m NS by 50m EW by 2mRL were used with sub-celling to 25m NS by 12.5m EW by 0.5m RL to enable adequate volume resolution. Resource classification was developed from the confidence levels of key criteria including drilling methods, geological understanding and interpretation, sampling, data density and location, grade estimation and quality.
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