Botswana Uranium Project (Impact 100%)
Impact's Botswana Uranium Project comprises approximately 27,000 sq km of Prospecting Licenses containing significant strike extensions to the host rocks found at the nearby Letlhakane Uranium Project owned by A-Cap Resources Limited (Figure 1). A-Cap have reported an Inferred Resource of 98 million lbs of U3O8 at an average grade of 158 ppm (100 ppm cut-off) hosted within near-surface calcretes of the Kalahari Group and sedimentary rocks of the Karoo Group. A-Cap has recently commenced a feasibility study into open pit mining and heap leach treatment of the resource.
Impact's licences are prospective for three types of uranium deposit:
- deposits hosted by Karoo sedimentary rocks;
- deposits hosted by calcretes within palaeochannels; and,
- deposits hosted within playa lakes.
During the 2009 work has focused on the compilation of previous exploration data including the open file data pertaining to coal drill holes within the Karoo Group. Over 100 wide-spaced drill holes provide valuable stratigraphic information about the sub-surface distribution of potential uranium host rocks surrounding and within the tenement areas.
In April 2009 the Company increased its landholding in Botswana to 27,000km² from an original 21,000km² following the grant of five new prospecting licences. On 19 August 2008 shareholders approved the purchase of the 15% of the original Botswana project it did not own for a consideration of 2 million ordinary shares to be granted to Mr. John Blaine.
Impact's initial interpretation of Government-supplied airborne radiometric data covering 75% of Impact's tenements in northeastern Botswana identified several prospective sites with elevated surface uranium responses. Five of these prospects have been prioritised for immediate follow-up work on the basis of widespread surface uranium anomalism in calcretes and sandstones, backed by regional mapping, ground reconnaissance work and sampling.
The prospects are called Lekobolo, Kodibeleng, Ikongwe, Shoshong and Sua Pan. Soil geochemistry programmes have commenced on these large areas with the aim of identifying specific targets that could be drilled commencing in late 2009, weather permitting.
Lekobolo: Calcrete and Karoo Sandstone target adjacent to the Letlhakane Project
The Lekobolo target lies on Impact's Licences P116/2008 and P117/2008, south of A-Cap Resources Letlhakane Project and their new discoveries at Serule West and Serule East.
Published data indicate that the Karoo-hosted primary uranium mineralisation at Letlhakane occurs close to the Archaean basement in a fault-bounded sedimentary basin fed by Karoo-aged palaeochannels recognisable in the radiometric and magnetic data.
The radiometric data also shows that the western and south western extensions of the uranium mineralisation at Letlhakane disappear under younger cover rocks and surficial sands.
The Lekobolo target area comprises the interpreted south western extension of the Letlhakane Project. The area is underlain by Karoo sandstone and siltstone units together with overlying calcrete and gypsum deposits, largely concealed by unconsolidated sand and soil. This has also diminished or completely blanketed any radiometric response from the underlying rocks.
However an east-west trending area up to 12 km long and 3 km wide contains elevated uranium responses, up to 20 ppm eU, in the airborne radiometric data. (Figure 2).
At the eastern end of this elongate area outcrops of Karoo sandstone contain up to 66 ppm eU (as measured with a handheld scintillometer). These sandstones are interpreted to form part of a west-draining Karoo palaeochannel that drains into a sedimentary basin concealed by the sands and calcrete, analogous to the geological setting at Letlhakane.
Kodibeleng - Ikongwe - Shoshong: 80km of calcrete drainage channels
These three target areas cover 80 km of large Cainozoic palaeo channels containing calcrete that is, in most places, buried by up to 5 metres of recent alluvium and soil. These palaeochannels are prospective for large calcrete-hosted deposits similar to Yeelirrie in Western Australia and Langer Heinrich in Namibia.
The headwaters of all three palaeo channels drain Archaean, Proterozoic and Karoo-aged rocks that contain elevated uranium values of up to 80 ppm eU (as measured with a handheld scintillometer). Such uranium-enriched source rocks have significant potential to generate uranium-enriched groundwater within the channels.
The extent of the calcrete in this part of Impact's Licences has not been recognised by previous explorers because of the sand and soil cover. At one locality in the Kodibeleng channel the hard surface of the calcrete has been eroded to reveal up to 3 metres of consolidated Kalahari sandstones and conglomerates containing up to 35 ppm eU (Figure 3). This is ten times greater than the surface response.
Sua: elevated radiometric uranium responses covering more than 200 sq km
The Sua target area comprises two very large areas of elevated uranium values totalling more than 200 sq kilometres in extent, between 5 and 10 ppm eU in the northern part of the pan and identified in regional airborne radiometric data.
The eastern area is 12 kilometres long and up to 5 kilometres wide, and the western area is at least 20 kilometres long by 15 kilometres wide (extending beyond the limit of the airborne data). Profiles exposed in 2 metre deep trenches have uranium values up to 15 ppm eU (as measured with a handheld scintillometer) at these depths (Figure 4). This indicates that the uranium is not a surficial feature and could represent an anomaly over a larger source at depth.
The Sua target area has strong similarities to the Manyoni Project in Tanzania (owned by Uranex NL) where uranium has been discovered 2 metres below the surface of playa lakes. At the C1 deposit, Uranex have reported an Inferred Resource of 46 Mt at 151 ppm uranium oxide (100 ppm cut-off) for a contained 15 million pounds of uranium oxide, within an area of about 5 sq kilometres.
