HIGHLIGHTS
This programme will be followed by a diamond drilling programme scheduled for later this month. The drilling programme is planned to confirm the results from previous exploration by drilling several twin holes, to test a revised model for the control of the uranium mineralisation and explore for extensions to the mineralisation identified between 1973 and 1984.
The drilling is planned at, and along strike of the Angelo A and Angelo B prospects. No exploration activities have been carried out on these prospects in the last 40 years. Piche holds three tenements totalling about 122km2 in its Ashburton Project (Figure 2).
Geology of Ashburton Project
Previous explorers focused their efforts on the unconformity between the mid Proterozoic sandstones and the early Proterozoic basement complexes.
Unconformity-related deposits constitute approximately 20% of Australia’s total uranium resources and about one-third of the western world’s uranium resources and include some of the largest and richest uranium deposits2. Minerals are uraninite and pitchblende. The main deposits occur in Canada (the Athabasca Basin, Saskatchewan and Thelon Basin, Northwest Territories); and Australia (the Alligator Rivers region in the Pine Creek Geosyncline, NT and Rudall Rivers area, WA2). In both Canada and Australia mineralisation is often found at the unconformity and in the basement complex well below the unconformity.
Uranium Mineralisation at Angelo River Prospect
Uranium mineralisation at Angelo River occurs along the Wyloo Group/Bresnahan Group contact. Two main zones of mineralisation have previously been identified: the A and B zones (Figure 3). The Lower Proterozoic Wyloo Group is represented by the Mt McGrath Formation (greywacke, shale, carbonaceous shale, sandstone, dolomite, dolomitic shale, sedimentary breccia), the Duck Creek Dolomite (dolomite, chert breccia, minor carbonaceous shale) and the Ashburton Formation (interbedded shale, mudstone, siltstone and greywacke). The Mid Proterozoic Bresnahan Group consists of medium to coarse sandstone, feldspathic sandstone and arkose.
Figure 3 shows the geology of the Angelo River Prospect. Angelo A zone mineralisation is hosted by a sequence of hematitic and/or carbonaceous shale and their brecciated equivalents, or mixed breccias containing chert, shale, sandstone and silicified dolomite fragments in a silty matrix. Most of the mineralisation at the Angelo B zone is hosted by a clay zone and is associated with iron oxide veining, although there is minor breccia-hosted mineralisation.
Piche’s Managing Director, Stephen Mann, commented:
“This project area is one of the most exciting unconformity uranium targets outside the Pine Creek Geosyncline in the Northern Territory and the Athabasca Basin in Saskatchewan Basin in Canada, two of the truly great uranium provinces in the world. Previous exploration has demonstrated that this area has all the most favourable attributes of both provinces. Additionally, historical results have highlighted the presence of high-grade uranium mineralisation in several areas within the project.
A regional review of the uranium mineralisation previously identified in the area, including geophysics (radiometrics, magnetics, electromagnetics), mapping and geochemistry suggest that the controls of the mineralisation may have been misinterpreted by previous explorers, and there remains considerable potential for the area to host very large, high-grade zones of uranium mineralisation. Piche’s focus on this upcoming drill programme will be to confirm historical drill results, and to test the revised structural model for the controls of uranium mineralisation. We currently have a programme of 2000m of reverse circulation and 1500m of diamond drilling planned, and follow-up drill programmes are already envisioned.
As each drill hole is completed it will be surveyed using a downhole gamma probe which will calculate an equivalent U3O8 concentration (eU3O8) based on the downhole gamma response. This technique is commonly used in uranium exploration and allows an early news flow of drill hole results. Drill core and drill chips with be assayed as checks, but the downhole gamma logging generally provides accurate eU3O8 grades and thicknesses. Consequently, Piche expects the first drill hole results will be available approximately two weeks after the drilling commences.
We are also pleased to have successfully recently completed a Heritage Survey with the registered Native Title party”.
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