Estrella Resources Limited (ASX: ESR) has intersected two broad zones of massive and semi-massive nickel-copper sulphides below the Carr Boyd workings in Western Australia.
The mineralisation was intersected in CBDD064, a diamond drillhole that was targeted across the dip of mineralisation to assist the company and CSIRO in understanding the relationship of the Carr Boyd mineralisation to the T5 Discovery on the Carr Boyd basal contact 1km away to the northwest.
The intersection confirms the continuation of nickel-copper sulphides below the old workings and coincides with a Downhole Electromagnetic (DHEM) response modelled from the top portion of CBDD056A which was drilled by Estrella into the basal contact in October 2021. The DHEM hole is too far from Shoot 4 at depth for any mineralisation to be detected.
The Carr Boyd Mine was worked between 1972 and 1976 by Western Mining Corporation (WMC) before being closed due to lowering nickel prices and WMC’s commitments elsewhere. A large fault had been identified as controlling mineralisation along the eastern edge of the main shoot. This fault was predicted to close off mineralisation at depth however this was a theory not proven before the mine closed. Predictions as to the location of the off-set mineralisation were tested unsuccessfully by drilling in the 1990’s and early 2000’s.
The mine fault has a similar orientation to an off-set in the basal contact identified by Estrella’s drilling last year. None of the historical core from the project was saved which will make identification of the magnitude and direction of the off-set of the fault more difficult. Subsequent drilling and limited DHEM around the workings have also failed to account for additional mineralisation except for an area called Shoot 4 which has received some drilling.
Of more importance to Estrella is to prove or disprove the concept that the Carr Boyd mineralisation was derived from a much larger pool of sulphides located on the T5 basal contact, the area within an intrusion where nickel-copper sulphides will most likely accumulate before later events remobilise those sulphides elsewhere.
Work by Estrella and the CSIRO should be able to resolve this link. If proven, the opportunity then exists that this large pool of sulphides still exists at depth. The company aims to continue to use drilling, DHEM and its seismic interpretation to explore this opportunity fully.
“I am highly encouraged by these latest rounds of results from CBDD064 as it confirms massive sulphide mineralisation continues below the old Carr Boyd workings,” Managing Director Chris Daws said.
“While our focus is very much on drilling, we are also highly focused on determining the Carr Boyd sulphide’s relationship to the T5 mineralisation found on the Basal Contact.
“Through our ongoing work with the CSIRO, which includes logging and geochemical analysis, we are highly confident on determining this link which, if it exists, means a very exciting time ahead for investors as it is proof this large pool of sulphides may still exist at depth.
“I look forward to updating investors as we progress with our findings and as we continue to explore this world-class opportunity.”
For further information please visit: https://www.estrellaresources.com.au/
