Broken Hill Prospecting Ltd (ASX:BPL) has confirmed copper-cobalt mineralisation on a new tenement along strike from the Broken Hill silver-lead-zinc ore body that has been worked continuously for more than 130 years.
Re-assaying of core taken from drilling of Burtt & Catterson’s Prospect in 1957 resulted in copper-cobalt results of up to 4.7 metres at 690ppm cobalt and 0.18% copper from 121.3 metres.
Another strong copper result of 5.5 metres at 0.34% from 234.2 metres was returned and BPL now plans detailed logging and further sampling of the historical core this month.
Investors have responded positively with shares up 30% to 6 cents early afternoon.
“Highlights mineral potential”
BPL managing director and CEO Trangie Johnston said: “The copper-cobalt results from re-sampling of historical core at the Burtt and Catterson prospect highlights the mineral potential of this world-class region.
“BPL’s expanded portfolio around Broken Hill has identified numerous targets within the Thackaringa Group of rocks emerging as a new style of mineralisation and exploration focus.”
In August BPL secured three new exploration licences covering 209 square kilometres of prospective terrain in the Broken Hill district, adding to existing tenement holdings in the Thackaringa area.
These tenements cover under-explored Broken Hill and Thackaringa Group rocks, with numerous base and precious metals, and industrial mineral prospects.
They significantly increase BPL’s holdings in a world-class mineral province.
Work on the Main Line tenement, which includes the historical Burtt & Catterson’s workings, has started with an examination of historical drill core and assay results.
Burtt & Catterson’s Prospect, about 8.5 kilometres southwest of Broken Hill, includes several historical bulldozer costeans, shallow pits and two shafts, 35 metres and 21 metres deep.
BPL’s extensive tenement holding in the world-class Broken Hill region.
Three diamond holes were drilled at the prospect in the 1950s but only cursory surface exploration has since been undertaken.
Review of data
In a review of data, assay intervals published in old Zinc Corporation and CRA exploration reports were of interest as they show thin bands with up to 4% copper in thicker silica and iron-rich lode rock intercepts.
In addition, a 5.5-metre interval historically assayed at 0.16% or 1600ppm cobalt.
The diamond core holes drilled by Zinc Corporation in 1957 were the only deep drill holes at the prospect and core is stored at the Geological Survey of NSW EC Andrews core facility in Broken Hill.
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Apart from rare cases such as the Thackaringa pyrite-cobalt deposits of BPL and Cobalt Blue Holdings Ltd (ASX:COB) and Copper Blow of Silver City Minerals Ltd (ASX:SCI), exploration for deposits hosted by the Thackaringa Group rocks were for many years discounted in favour of Broken Hill-type prospects.
Strong cobalt demand
Surging demand for cobalt has sparked a revival of exploration for economic copper and strategic metals in the iron-rich horizons that occur throughout the Thackaringa Group.
Rock chip sampling by BPL, Silver City Minerals and others around Broken Hill, has demonstrated that widespread copper-cobalt geochemical anomalism at surface is associated with Thackaringa Group rocks.
Current work is aimed at defining these anomalies through more comprehensive sampling and ground-based geophysical techniques such as induced polarisation.
BPL will geologically log the three 1957 holes in detail aimed at recognising indicator lithologies, including ironstone, garnet-rich lithologies and quartz–gahnite rocks.
Any further mineralisation identified will be assayed for a full economic metal suite including gold.
It is expected that follow-on work will involve compiling the original company mapping after establishing GPS ground control points, including accurate location of the original drill collars.
Following the site reconnaissance, geological traversing; 3D interpretation and modelling; near-surface sampling programs; and exploration drilling will follow if warranted.