ASX-listed uranium, nickel and gold explorer Impact Minerals asserts that Botswana is fast growing its reputation as one of the best modern-era uranium mining provinces on the African continent, owing to the company’s discovery of three deposits and a new emerging discovery at its Red Hills prospect.
The discovery of the Lekabolo deposit, in 2010, led to the discovery of further deposits, namely Mosolotsane and Morolane, and has delivered substantial explor- ation opportunities in eastern Botswana.
Impact Minerals is the largest ground holder for radio- active mineral rights in Botswana, with a total of 41 100%-owned prospecting licences covering 26 000 km2.
“With sand cover obscuring airborne radiometric responses, Botswana was ‘off the radar’ until the 2006 discovery of explorer A-Cap Resources’ Lethlakane deposits, near Serule, which is now a 261-million-pound uranium oxide resource at a grade of 150 parts per million (ppm),” says Impact Minerals MD Dr Mike Jones.
The Lekabolo deposit, discovered in 2010, is at an advanced exploration stage, although a resource is yet to be defined. Drilling indicates that the deposit has the potential to host about five-million pounds of uranium oxide at a grade of 150 ppm, a similar grade to that of the Letlhakane deposit, only 20 km away, says Jones.
Further small deposits have been found at Mosolotsane and Morolane, each probably hosting about two-million pounds of uranium oxide at a similar grade to that of Lekabolo.
“These are unlikely to be economically viable to mine but they demonstrate that other uranium deposits similar to Lethlakane do exist in Botswana,” states Jones.
He adds that the discovery of the large alteration system at Impact Minerals’ Red Hills prospect is the company’s most exciting development. Although it is not a deposit yet, it indicates that large uranium- bearing mineralised systems occur in rocks much older than the Karoo-aged sandstone and mudstone at Letlhakane.
The large Red Hills alteration system is about 1 km × 1.5 km and about 200 m thick. It contains a significant amount of low-grade rare-earth elements and uranium, as well as base and precious metals, namely lead, zinc and silver.
Impact Minerals has termed this system a ‘halo’ that may be close to a large high-grade uranium deposit. The system may be similar to the high-grade uranium deposits found in similar aged rocks in the Athabasca basin of Canada, which hosts some of the world’s largest and highest-grade uranium mines.
“The alteration system discovered at Red Hills has not been reported in Botswana before and is a major breakthrough in the understanding of the untapped but emerging modern-day uranium potential of Botswana,” says Jones.
Follow-up gravity surveys are currently in progress at the Red Hills prospect, with plans for further drilling in the middle of the year.
Impact Minerals’ aim is to perform follow-up exploration drilling at Red Hills and surrounding areas this year, as the Red Hills prospect lies on a major fault, which extends for about 60 km along strike within its ground.
“There has been no exploration of this fault and the blue-sky potential is enormous,” asserts Jones.
The main challenge posed by Botswana’s environment when undertaking exploration activities is seeing through the sand cover; however, with the development of both geophysical and geochemical techniques, new areas have been opened up for exploration, while allowing previously thought-to-be well- explored areas to be revisited.
Impact Minerals has been successful in its uranium explor- ation, owing to good old- fashioned mapping and rock chip sampling, as well as more modern techniques such as airborne magnetic and radiometric data, as well as Mobile Metal Ion technology, used to conduct soil geochemistry surveys, which have the demonstrated ability to detect mineral deposits under thick cover.
“The use of these techniques by us and others has led to the many discoveries made over the past five years in Botswana,” notes Jones.