Tertiary Minerals Plc has started drilling at its Target A1 silver oxide discovery within the Mushima North project in northwest Zambia.
The 4,000-metre reverse circulation programme is the largest the company has undertaken in Zambia to date.
Work is intended to support a maiden mineral resource estimate at Target A1, where Tertiary has already reported an exploration target of between 15 and 30 million tonnes at a grade of 40 to 60 grams per tonne of silver equivalent.
That equates to a target of up to 58 million ounces of silver equivalent, measured against the JORC code, the Australasian standard for reporting mineral resources.
The effort will also test extensions to the known mineralisation and provide initial drilling at two further prospects, Target A1 west and Target A2.
Target A1 is a near-surface, tabular body roughly 500 metres long, 300 metres wide and up to 75 metres thick, and remains open to the northwest, southwest and at depth.
The mineralisation is also associated with elevated levels of bismuth, antimony and gallium, though these have yet to be fully investigated.
Holes will be drilled to a vertical depth of up to about 125 metres, with the programme expected to take six to 12 weeks to complete.
Samples will first be analysed on site using a portable X-ray fluorescence analyser, with selected intervals sent to a certified external laboratory, and the first assay results are expected six to eight weeks after the initial batch is submitted.
Richard Belcher, managing director, said the programme aimed both to define a resource and to test possible extensions of the mineralisation.
The project sits 28 kilometres east of the historic Kalengwa copper mine, one of the highest-grade copper deposits ever mined in Zambia, which is currently under redevelopment.
