Great Boulder Resources (ASX: GBR) has intersected “extensive” massive sulphide mineralisation, indicating the presence of nickel and copper, within the Eastern Mafic complex of its Mt Venn project in Western Australia.
To-date, 15 holes have been drilled and have unearthed “significant” sulphide mineralisation at five anomalies.
According to the company, the drilling has established that sulphides are the source of the electromagnetic conductors identified during airborne and ground surveys.
At the ML 12 anomaly, drilling has defined more than 200m of mineralised strike, which remains open in all directions.
Great Boulder anticipates the strike length is greater than 400m and has planned more drilling to target extensions to the identified strike.
The sulphide mineralisation intersected at ML 12 and ML 15 has also firmed up the company’s confidence that it has uncovered more nickel-rich sulphide mineralisation within the Eastern Mafic complex.
In total, Great Boulder has intersected mineralisation across more than 5km of strike, with the company saying it has confirmed a “substantial magmatic sulphide system” at the Eastern Mafic complex.
The mineralisation is predominantly pyrrhotite with pyrite, chalcopyrite (copper sulphide) and pentlandite (nickel sulphide), with Great Boulder saying the existence of pentlandite supports its theory that the Eastern Mafic complex hosts more nickel compared to the larger Mt Venn system.
Earlier drilling across the Mt Venn complex within project returned 44m at 0.5% copper, 0.2% nickel and 0.06% cobalt from 153m downhole, 21m at 0.6% copper, 0.2% nickel and 0.06% cobalt from 30m downhole, and 9.5m at 1% copper, 0.1% nickel and 0.02% cobalt from 178m downhole.
Assays remain pending for these latest drill intersections and will provide an accurate determination of mineralisation and grades.
Great Boulder will follow up discrete anomalies identified from the airborne EM survey with ground EM work to identify conductor plates.
Once this has been completed and the assays received, Great Boulder will begin its next round of drilling at the Eastern Mafic.
Shares in Great Boulder soared on today’s news – rocketing 24% to reach A$0.485 by midday.