Deep Drill Testing To Expand Mineralised Footprint
St George Mining Limited (ASX: SGQ) has identified what it describes as a “significant” new EM conductors at its flagship Mt Alexander Project, located in the north-eastern Goldfields of Western Australia.
DHEM surveys on the completed drill holes are being used to identify discrete EM conductors for follow-up drilling as part of the current drill programme at Mt Alexander where there is a focus on deeper drilling
The drill tests are being undertaken on conductive features identified by a number of geophysical surveys completed by St George across the Cathedrals Belt. The drill targets are located below and down-dip from the shallow high-grade deposits already discovered in the Belt.
Drill hole MAD184 was completed to a downhole depth of 497.8m to test a broad single component (Z) EM anomaly identified by the surface SQUID MLEM survey carried out earlier this year. The drill hole intersected a 23.2m thick mafic-ultramafic unit from 444.5m downhole. This was highly encouraging because these types of intrusive rocks are known to host massive sulphide deposits in other parts of the Cathedrals Belt.
More significantly, the drill hole intersected 5m of disseminated and blebby nickel-copper sulphides from 462.7m downhole. These disseminated and blebby sulphides can represent the halo around proximal massive sulphide mineralisation and support the potential for the presence of higher-grade mineralisation nearby.
The DHEM survey in MAD184 recorded a very strong off-hole anomalous response to the east and down dip at 475m downhole. The response was seen in the mid to late times with a modelled conductivity of 49,000 Siemens, which is consistent with a massive sulphide source. A second anomaly was detected to the north- west of the drill hole and has a modelled conductivity of 16,200 Siemens.
Importantly, given the large distance of MAD184 from other drill holes, any potential high-grade mineralisation at this location is open in the direction beyond the anomalies.
Executive Chairman, John Prineas, said the new DHEM conductors provide potential to significantly increase the footprint of known high-grade mineralisation in the large mineral system at the Cathedrals Belt,” Mr Prineas said.
“Our deep drill programme is delivering excellent results with thick intrusive-style rocks and nickel-copper sulphide mineralisation intersected at depths not previously explored.
“The downhole EM surveys have delivered the breakthrough moment with two new exceptional conductors identified from MAD184 that are both interpreted to represent massive nickel-copper sulphides.
“The MAD184 conductors are particularly exciting as they are the deepest conductors ever identified in the Cathedrals Belt and located 800m to the west of previously intersected massive sulphides on the Cathedrals Belt.
“The potential discovery of massive sulphides at these new conductors could be our most important discovery to date as it would confirm the continuity of the high-grade mineralisation at depth and upgrade the western extension of the Cathedrals Belt – which covers the 2.5km long West End Prospect that straddles the major Ida Fault – as a fertile and highly prospective area for further mineralisation.
“The Cathedrals Belt is interpreted to dip to the north-west at about 40 degrees so, from a geological perspective, the MAD184 conductors are in an ideal location for the presence of massive sulphide mineralisation down-dip from the high-grade mineralisation already discovered near surface. “With a 100% success rate in testing these kinds of conductors in the Cathedrals Belt, we are confident that our next significant discovery of massive nickel-copper sulphides is imminent.”