Askari Metals says a detailed trench sampling campaign at its Uis project in Namibia has revealed a more significant lithium-rich pegmatite system than interpreted during initial mapping, with an average thickness of about 10m.
The company says the main pegmatite body has been mapped along a strike of about 2km and includes a south-west zone with an average thickness of 21m along 350m of strike … and peak thickness reached 26m.
Management put 44 trenches into the OP target at Uis where it has identified a suite of lithium-caesium-tantalite (LCT)-style pegmatites occupying a distinct north/north-west-trending corridor of interest. An initial spacing of 40m was planned for the first phase of trenching.
The OP target was identified through surface mapping and interpretation of remotely-sensed hyperspectral imagery and the company has undertaken initial rock chip sampling and a first phase of reverse-circulation (RC) drilling along a short strike of the system. Drilling results include intercepts of 3m grading 0.35 per cent lithium oxide and 1m going 0.41 per cent, although management says it does not see the results as being representative of the main pegmatite.
A diamond drill rig is expected to be mobilised during the current quarter for the maiden drill-testing of the OP pegmatites.
Askari Metals chief exploration and project manager (Africa) Cliff Fitzhenry said: “Trench mapping of the OP target has yielded significantly better than expected results with a zone of multiple pegmatites in a ~2.0km zone comprising a main pegmatite body with several smaller bodies which are interpreted to be bifurcating offshoots from the main body. Channel sampling across the OP pegmatites is well advanced and assays are being fast tracked through the laboratory and will be released to the market, likely later this month.”
Significantly, the OP target lies in the extreme north-east corner of the relevant exploration permit area, which puts it just 4km west of Andrada Mining’s operational Uis tin project. The Andrada project has a mineral resource estimate of 81 million tonnes at a grade of 0.15 per cent tin, 0.73 per cent lithium oxide and 86ppm tantalum and possesses significant by-product potential for lithium and tantalum.
Andrada’s Uis orebody comprises five major clusters of pegmatites across the length of its mining operation. While the principal axis of mining along the open pit is north/north-east, the same direction as Askari’s pegmatite corridor, the individual pegmatite bodies appear to be oriented in a more east/north-east direction.
And Askari’s OP target area is by no means alone as the company has a string of targets in its licence running off to the south-west along the same strike for about 12km, including the PS, DP K9, C1 and B1 targets – all centred within the same north/north-east trend of its “corridor of interest”.
Importantly, the recent trenching has been pivotal for the project as it confirms the system is not just a single pegmatite body, but shows it consists of a myriad of semi-parallel bodies that split from or converge on a line of bigger bodies that form its main alignment.
That complexity has become more apparent after the trenching program because the shallow surface cover required stripping away before trenching could begin, thereby exposing the extent of pegmatite occurrence.
The resulting distinction between “before” and “after” interpretations of pegmatite distribution is stark and a testimony to the advantages of taking the time to get a better look at the overall structure and distribution. The company is now looking at a real pegmatite swarm within a structural line of weakness exploited by the pegmatite intrusives.
Following encouraging results from a limited first phase of trenching across the OP target, Askari extended the program along the full 2km strike of the target and says mapping of the current trenching has been completed. All of the pegmatites intercepted are being channel sampled at 1m intervals and the work is expected to be completed in a week.
So far, 725 samples have been submitted for analysis, with the first results expected before the end of the month.
Askari says it will now focus on finishing off the mapping of its K9, PS and DP pegmatite targets before the end of the month, fast-tracking sample analyses and getting its hands on a diamond drill rig as soon as possible so it can test its best targets.
The company also plans to kick off further mapping and rock chip sampling of its other exploration permit area and subject to encouraging analytical results from the current batch of samples, it expects to mobilise an excavator for the first phase of trenching in its second licence area.
Management says the company will also continue with regional-scale stream and soil geochemical sampling programs along the corridor of interest to define additional pegmatite targets.
Askari’s trenching program has been a great success and is a model for other companies to emulate in relevant circumstances, especially where surface cover is abundant. With an operational LCT mine just outside and immediately on-strike from its many targets, the company appears well-placed for a meaningful discovery at Uis.
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By Doug Bright
