Joint venture partners Coda Minerals (ASX: COD) and Torrens Mining (ASX: TRN) have uncovered intense iron oxide-copper gold (IOCG) alteration with copper-sulphide mineralisation while drilling at the Emmie Bluff Deeps target within the Elizabeth Creek copper project in South Australia.
The first deep diamond hole drilled at the target encountered a sequence of approximately 200m of intensely haematitic and altered sediments and granites, including 50m of moderate-to-intense copper-sulphide mineralisation consisting of chalcocite, chalcopyrite and bornite.
The host-rock alteration assemblage includes chlorite, baryte, sericite and potassium feldspar, which are all typical of world-class IOCG deposits in the region such as BHP Group’s (ASX: BHP) Oak Dam West discovery located 16km to the northeast and Oz Minerals’ (ASX: OZL) Carrapateena project 50km to the east.
Portable XRF (X-ray fluorescent) readings have also indicated the presence of copper and highly-elevated levels of pathfinder elements such as lanthanum, cerium, cobalt and molybdenum.
Coda chairman Keith Jones said the drilling results were to be expected given Emmie Bluff Deep’s location in elephant country.
“We know the enormous potential of our tenure [and] it is tremendously exciting for our first deep exploration hole at Elizabeth Creek to have intersected evidence of a major IOCG system existing on our ground,” he said.
“This is the first drill-backed evidence obtained to support our IOCG exploration model [and] we are looking forward to exploring the significant potential of this mineralised system.”
Emmie Bluff Deeps is a geophysically-targeted IOCG prospect which forms part of the Elizabeth Creek project in the heart of South Australia’s Olympic province.
Coda is the operator and majority owner of Elizabeth Creek with 70% equity, and Torrens retains the remaining 30%.
Elizabeth Creek covers 739 square kilometres and encompasses two priority targets – Emmie Bluff copper-cobalt and Emmie Bluff IOCG Deeps – which are being explored through the current drilling program.
Emmie Bluff copper-cobalt is a laterally-extensive, flat-lying, sediment-hosted deposit at approximately 400m depth, where Coda released an initial exploration target in 2019.
Emmie Bluff IOCG Deeps lies in the basement rocks below Emmie Bluff, at up to 1,000m deep and contains the regionally-prolific IOCG mineralisation.
‘Exciting and significant result’
Coda chief executive officer Chris Stevens said the IOCG discovery was a “very exciting and significant result” for the first deep IOCG exploration hole to be drilled at Elizabeth Creek.
“Regardless of the final assays, it is clear based on geological data alone we have intersected an IOCG alteration system of significant scale,” he said.
“We are encouraged to have encountered chalcocite, chalcopyrite and bornite at the intensity and over the length of core that we did, and we are currently investigating options to follow up these results as soon as possible.”
Coda has approvals in place for multiple additional holes and anticipates mobilising a third diamond rig to Emmie Bluff Deeps in the coming days.
The work will proceed in parallel with ongoing resource infill drilling covering the shallower, Zambian-style copper-cobalt mineralisation at Emmie Bluff, where Coda remains on track to deliver a maiden mineral resource estimate later this year.
“Given the size of the prize, together with the location of Emmie Bluff Deeps in a tier-one mineral province just 16km from one of the world’s most exciting new IOCG discoveries, we feel that we owe it to our shareholders to pursue this game-changing opportunity with vigour,” Mr Stevens said.