St George Mining is exploring for nickel-copper depth extensions at its Mt Alexander project in Western Australia, with a diamond hole currently around 795m below the surface. The hole is planned to target an exciting conductive feature below the Investigators prospect. Encouraging geology in the new hole points to the potential for another nickel belt, parallel to the prolific Cathedrals Belt, according to St George.
The company has embarked on an ambitious fact-finding program to drill into a deep conductive feature lying directly underneath and to the north of its Investigators nickel deposit. The feature was identified from a magnetotelluric or “MT” geophysical survey, recently completed across the Cathedrals Belt.
Higher conductivities are sometimes associated with massive sulphide minerals, which can harbour base metals such as nickel and copper.
“Hole 180” is the first deep hole designed to test this geophysical feature and was collared, or started, about 500m north of the existing shallow nickel-copper mineralisation at Investigators.
St George previously said the down plunge extension of the Investigators mineralisation could lie about 500m below surface and on the way down to its intended target, hole 180 intersected about 6m of ultramafic rocks from 22.5m that contained a narrow band of weathered sulphide mineralisation.
Management said the ultramafic unit may represent a new greenstone belt that lies parallel and to the north of the known Cathedrals Belt.
St George said that hole 180 contains a thick granite sequence and elsewhere in the Cathedrals Belt, these granites are associated with ultramafic and mafic hosted nickel-copper mineralisation.
Encouraged by the geological similarities in hole 180 and known mineralisation elsewhere in the prospective belt, St George will persevere and keep on drilling.
At its present depth of 795m, hole 180 has intersected some troublesome ground conditions and cannot progress any further. To deviate around this zone, St George’s drilling contractor will insert an angled diamond drill wedge at about 524m down the current hole in order to continue to its intended target.
A second diamond drill rig has also kicked off at the Cathedrals prospect this week.
St George said that “hole 182” is planned to a depth of 700m and will also test a large conductive feature identified by the MT survey, interpreted as the down plunge extension of the nickel-copper mineralisation at Cathedrals.
St George Mining’s Executive Chairman, John Prineas, said: “Notwithstanding our inability to complete the drilling of MAD180 as planned, the rocks intersected in the hole so far show positive signs for the potential in deeper areas of Investigators.”
“This remains a compelling target and we look forward to getting MAD180 back on track to test the large conductive anomaly at Investigators.”
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