St George Mining Ltd (ASX:SGQ) has received further strong results from step-out drilling at the Mt Alexander project in WA with one hole intersecting thick nickel-copper sulphides 80 metres down-plunge of known mineralisation.
A large step-out hole at Investigators prospect intersected breccia and stringer sulphides with this style of mineralisation indicative of sulphides remobilised from a larger, proximal source.
High-grade nickel-copper sulphides
The shallow, high-grade nickel-copper sulphides discovered along the Cathedrals Belt are associated with mafic-ultramafic intrusions.
These are interpreted to have passed upwards from the Earth’s mantle through structures in the belt’s northern margin.
Deeper drilling to track the mineralised intrusive units down-plunge of the shallow deposits has intersected these units in their interpreted down-dip extension.
Downhole EM (DHEM) surveys in these deeper holes have identified seven strong off-hole EM conductors, which are excellent targets for discovery of further nickel-copper sulphide mineralisation.
“System is ‘live’ at depth”
St George Mining’s executive chairman John Prineas said: “The new EM targets from the deeper holes indicate that the large, high-grade mineral system at the Cathedrals Belt is ‘live’ at depth.
“With all EM conductors drilled in the Cathedrals Belt confirmed as nickel-copper sulphides, the new EM conductors present a tremendous opportunity to make further discoveries and to confirm the continuation of mineralisation down-plunge.
“We are seeing increasing potential for significant mineralisation at depth and are excited to be escalating our drill program to more intensely test this priority target area.”
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Schematic long section of Investigators showing drill hole traces and location of new EM conductors down-plunge of known mineralisation.
6.5 metres intersected
The latest deep stratigraphic hole to be completed at the Cathedrals Belt is MAD168, which was drilled to a downhole depth of 301 metres and intersected 6.5 metres of nickel-copper sulphides from 227.1 metres downhole.
The sulphides were intersected in the interpreted down-dip continuation of the Investigators ultramafic unit.
MAD168 is a large 95-metre step-out to the north of the previously known mineralisation in MAD123 and confirms a significant extension of the down-plunge strike of high-grade mineralisation at Investigators.
DHEM surveys have yet to be carried out in all recently completed deep drill holes and additional targets may be identified.
Drill results have shown that large volumes of mineralisation, including massive, semi-massive, matrix and disseminated sulphides, can occur around the modelled EM plates but are not detected by EM surveys.
Drilling continues
Diamond drilling is continuing with MAD169 in progress at Investigators.
This is another deeper stratigraphic hole planned to a depth of 300 metres and is designed to test for further mineralisation in the down plunge area.
Map of the Mt Alexander tenements with key prospects on the Cathedrals Belt highlighted.
At the Radar and Bullets prospects, a reverse circulation (RC) drill rig is expected to arrive at site soon to begin follow-up drilling.
Radar is the fourth discovery across 5.5 kilometres of strike of the east-west oriented Cathedrals Belt and is 1.2 kilometres east of the Cathedrals Prospect.
Assays from the MAD152 discovery hole confirmed high-grade mineralisation with 6 metres at 2.14% nickel, 0.74% copper and 1.62 g/t PGEs from 46 metres.
At Fish Hook prospect assays for the recently completed soil survey are pending and following a review of these, an EM survey and/or drilling will be progressed.
The crew for the moving loop EM (MLEM) survey planned for West End prospect is due to return to site shortly.
They will complete the MLEM survey towards the Ida Fault in the western section of the Cathedrals Belt.
Mt Alexander is 120 kilometres south-southwest of the Agnew-Wiluna Belt, which hosts numerous world-class nickel deposits.