|St George Mining’s new EM conductor points to growing Mt Alexander nickel-copper sulphide potential |
The growing number of significant mineralised intercepts and downhole EM conductors at West End and Investigators demonstrates a very large and fertile mineral system.
St George Mining Ltd ( ASX:SGQ) has identified a new electromagnetic (EM) target for massive nickel-copper sulphides at its flagship high-grade Mt Alexander Project in the north-eastern Goldfields of Western Australia.
The company has detected a strong off-hole EM conductor identified from the downhole EM (DHEM) survey in drill hole MAD202 at the West End prospect.
Importantly, the new conductor is within a ‘field of EM conductors’ recently identified at the West End and Investigators prospects, indicating a potential for the presence of a significant volume of mineralisation in or near this area.
“Growing number of significant mineralised intercepts”
St George executive chairman John Prineas said: “Our systematic and concurrent use of drilling and downhole EM surveys has delivered another stand-out result with the identification of one of the most exciting EM conductors at Mt Alexander to date.
“We have a 100% success rate in confirming conductors of this kind as nickel-copper sulphides, so we are confident that drilling this target will deliver another discovery of high-grade mineralisation.
“The growing number of significant mineralised intercepts and downhole EM conductors at West End and Investigators demonstrates a very large and fertile mineral system and further supports the potential for a significant deposit in this area.
“With demand for new sources of nickel sulphide booming and investors actively looking for nickel growth stories, we are excited that more opportunities to expand the mineralised footprint at Mt Alexander are continuing to evolve for our shareholders.”
A compelling target for mineralisation
The EM conductor is modelled with a conductivity of 81,000 siemens, one of the highest of any conductor identified at Mt Alexander to date.
The conductor was observed in the mid to late time data of the DHEM survey and recorded a time constant of 100 milliseconds; the combination of conductivity and time decay of this kind are typical of massive sulphides.
Promisingly, the new EM conductor is coincident with a trend of prominent gravity highs that are interpreted to represent dense rocks – further confirming the conductor as a compelling target for mineralisation.
MAD201 was drilled as the first step-out hole from the deep MAD199 discovery at Investigators which intersected:
MAD201 intersected 2.4 metres of nickel-copper sulphides from 434.6 metres downhole – 125 metres down-plunge of MAD199 – with assays now confirming:
- 11.07 metres at 1.58% nickel, 0.71% copper, 1.23g/t total PGEs from 333.5 metres;
- 3.9 metres at 3.98% nickel, 1.8% copper, 3.1g/t total PGEs from 340.67 metres; and
- 1.28 metres at 6.54% nickel, 2.96% copper, 3.88g/t total PGEs from 342.12 metres.
The field of multiple EM conductors identified at West End and Investigators suggests that this area is a very active part of the Cathedrals Belt mineral system, with the potential for the conductors to be associated with a greater volume of mineralisation along strike or down-dip.
- 2.4 metres at 1.66% nickel, 0.55% copper, 0.52g/t total PGEs from 434.6 metres; and
- 0.26 metres at 6.18% nickel, 1.2% copper, 0.79g/t total PGEs from 436.76 metres.
St George has further diamond drilling planned to test the EM conductors at West End and Investigators.
Surface-based EM surveys cannot reliably see to the depths of the new EM conductors, requiring the continued concurrent use of diamond drilling and DHEM surveys to scope out the extent of the deeper mineralisation.
Prior to the commencement of the diamond drilling program, a seismic survey will be completed over parts of West End and Investigators.
The scheduled start of the seismic survey was delayed because of the unavailability of the field crew due to interstate travel restrictions arising from COVID-19 issues in NSW.
The seismic survey is now expected to commence within the next few weeks.