The Valhalla uranium deposit is located 40km north-west of Mount Isa on Exploration Permit for Minerals (EPM) 9221. Previous drilling by Queensland Mines Ltd in the 1960’s, and SRA in the 1990’s and 2000’s, established a combined Measured, Indicated and Inferred Resource of 56Mlb of U3O8 grading 0.14%. Substantial widths of high grade uranium mineralisation in albite-carbonate-hematite breccias and mylonites as well as altered mafic schists have been intersected in the latest drilling at Valhalla. The deposit is hosted within basalts and basaltic sediments of the Eastern Creek Volcanics, trends north–south and is approximately 1,100m in strike length.
A resource estimate conforming to the JORC guidelines for the Valhalla uranium deposit has now been completed following validation and compilation of data from drilling undertaken earlier in the year. The estimate covers the original Valhalla deposit as well as the south eastern extension, Valhalla South.
The updated Mineral Resource estimate for the Valhalla uranium deposit is quoted using a cut-off grade of 230ppm U3O8.
|
Mt |
Grade ppm U3O8 |
Tonnes U3O8 |
Mlb
U3O8 |
|
| Measured Resources |
12.66 |
833 |
10,549 |
23.2 |
| Indicated Resources |
18.53 |
900 |
16,680 |
36.7 |
| Total Measured + Indicated |
31.20 |
874 |
27,229 |
60.0 |
| Inferred Resources |
5.2 |
859 |
4,494 |
9.9 |
(Figures may not add due to rounding)
Measured and Indicated Mineral Resources increased by 9.9% to 60.0Mlb U3O8 (27,229t U3O8) from previously announced 55.4Mlb U3O8 (25,153t U3O8). Total Resources increased from previous 67.5Mlb U3O8 to 69.9Mlb U3O8.
The main Valhalla deposit now has a strike length in excess of 1,100m with mineralisation extending from surface to a depth of over 650m. It is structurally controlled with a characteristic southerly plunge. Valhalla South is located approximately 600m along strike to the south-east of the main mineralised zone and has a strike length of at least 400m and appears open both along strike and at depth. Summit completed the planned drilling programme of 52 holes for 11,739m at both Valhalla and Valhalla South by the end of June 2009. These holes have been drilled on a nominal 80m x 40m grid pattern to infill the existing drill holes and replace some historic drill holes as well as extend the known mineralisation at Valhalla South along strike and at depth. The majority of these drill holes have been gamma logged down hole and gyroscopically surveyed to obtain an accurate hole orientation using company owned equipment. The resource dataset is a combination of chemical assays and appropriately calibrated down hole gamma logging. Gamma derived grades have been validated against both XRF and chemical assay derived grades.