The second completed exploration hole in the latest program of Cobre Ltd (ASX:CBE) at the Ngami Copper Project (NCP) in Botswana points to more than 4 kilometres of anomalous copper along strike from the Comet target.
Drill hole NCP56 intersected widespread disseminated fracture and cleavage hosted chalcocite mineralisation from 159 to 192 metres downhole varying from an estimated 0.1% chalcocite to 4% chalcocite across the section
This hole is 2 kilometres along strike from NCP55 which last week also provided encouraging signs for Cobre of the potential for expansion at Ngami, which is in the Kalahari Copper Belt (KCB) in Botswana.
READ: Cobre hits new copper mineralisation 7.5 kilometres along strike from Comet Prospect at Ngami in Botswana
New portion of contact
Both these exploration holes were designed to test a new portion of contact more than 7.5 kilometres along strike from the Comet target with this new area now called the Cosmos target.
The sulphide observed in both holes indicates that the anomalous copper intersected in hole NCP42 of 15 metres at 0.5% copper and 13 g/t silver from 142.5 metres in May 2023 may extend for more than 4 kilometres indicating that Cosmos may have the potential to be a sizeable new target.
Another great result
Cobre’s chief executive officer Adam Wooldridge said: “This is another great result, demonstrating anomalous copper mineralisation occurs in a previously untested portion of the prospective contact.
"Importantly, the current hole builds on last week’s announcement demonstrating that we have strike continuity of mineralisation for over 4 kilometres which will add to our significant exploration target.”
While the values in NCP55 and NCP56 are based on visual estimates supported by pXRF measurements, they point to the potential for significant additional NCP mineralisation building on the conceptual exploration target estimated at between 103 and 166 million tonnes at 0.38 to 0.46% copper.
Infill drilling
Sample assays from the holes are expected in February 2025.
The exploration drilling is being carried out before infill drilling designed to upgrade a portion of the exploration target into a JORC category following the completion of a mineral resource estimate.
Approximately 4,500 metres of planned infill drilling is underway at the Comet target.
About hole NCP56
NCP56 intersected about 60 metres of Kalahari Group along with an additional 35 metres of underlying conglomerates and mudstone cover rocks.
The underlying lower D’Kar Formation is characterised by a sequence of steeply dipping folded sandstones and interbedded siltstones which increase in thickness towards the contact with oxidised footwall sandstones of the Ngwako Pan Formation at 192 metres downhole.
Copper mineralisation is dominated by widespread fine-grained cleavage and fracture-hosted chalcocite mineralisation extending from 159 to 192 metres downhole.
A combination of detailed logging supported with regularly spaced pXRF measurements was used to provide an estimate of copper abundance downhole.
Mineralisation style
Drilling to date has returned consistent, wide intersections of anomalous to moderate-grade copper-silver values over extensive strike lengths with smaller structurally controlled higher-grade zones.
This style of mineralisation is dominated by fine-grained chalcocite which occurs along cleavage planes and in fractures rather than the vein-hosted bornite with chalcopyrite more typical of the KCB style.
Importantly, the chalcocite mineralisation is amenable to acid leaching, occurs below the water table and is associated with well-developed fracture zones bounded by more competent hanging and footwall units satisfying key considerations for ISCR.
Target (NYSE:TGT) model
The NCP is near the northern margin of the KCB and includes significant strike of subcropping Ngwako Pan/D’Kar Formation contact on which the majority of the known deposits in the KCB occur.
Cobre is aiming to prove a similar ISCR process to Taseko Mines’ Florence Copper Deposit of 320 million tonnes at 0.36% copper and Copper Fox’s Van Dyke Deposit of 265.6 million tonnes at 0.29% copper in Arizona which both share a similar scale to NCP.