Wide-spaced resource drilling at the Carriere de l’Este pegmatite deposit within AVZ Minerals’ (ASX: AVZ) Manono lithium-tin project in the Democratic Republic of Congo has confirmed high-grade mineralisation directly beneath thin soil and laterite cover.
Assay results from four new “step-out” holes located on section lines along strike from initial drilling in 2017 have identified additional high-grade spodumene-rich zones for future infill resource estimation programs.
Best intersections included 12.05 metres at 2.41% lithium oxide and 735 parts per million tin; 21.09m at 2.1% lithium oxide and 943ppm tin; and 16m at 2.49% lithium oxide and 571ppm tin.
All holes were collared in slightly weathered pegmatite from top of hole and returned significant intersections of more than 2% lithium oxide.
The Carriere de l’Este pegmatite deposit is now confirmed at 1.2 kilometres in length and remains open at both ends and down dip.
Higher-grade areas
AVZ managing director Nigel Ferguson said the results will assist in targeting areas of higher grade material (greater than 2% lithium oxide) at shallow depths as potential spodumene concentrate feed material to Manono’s new processing plant.
“The assays from these four new holes show highly-encouraging mineralisation 400m closer to the historical [Carriere de l’Este] open pit, as well as a more complex geology with intrusions of aplitic pegmatite and dolerite possibly along late-stage faults,” he said.
“The holes were deliberately spaced widely to help track the location of high-grade zones mapped further to the southwest along this massive deposit and to that extent, [our] drilling has been successful.”
Infill work
The information will now be used to plan focused infill work along the high-grade zones including a closer drilling pattern to generate near-surface indicated or measured resources for conversion to reserves prior to commissioning of the plant.
“The possible delineation of high-grade future reserves has the potential to initially feed higher-grade ore to the plant, providing increased spodumene concentrate production volumes from the start of operations,” Mr Ferguson said.
“[Additionally] despite future tin production accounting for only a small percentage of Manono’s overall revenue, a strengthening tin and tantalum price continues to justify some exploration expenditure to gain information on the potential scale of these deposits which may sustain a separate tin mining business,” he added.
