St George Mining’s ongoing exploration at its Mt Alexander project in WA’s north-eastern Goldfields is gradually painting a picture of what could be a significant mineralised system. The company’s latest efforts saw multiple downhole EM, or “DHEM”, conductors light up adjacent to its latest deep diamond drill holes which were positioned along the north-western extension of the Cathedrals Belt prospect.
The company has two diamond rigs drilling simultaneously in its deep exploration drilling campaign to vector in on more massive sulphide mineralisation at Mt Alexander.
As a major part of its ongoing nickel exploration program along the Cathedrals Belt prospect, St George logs downhole EM surveys in its drill holes to assist in targeting the location of the EM conductors, or ‘EM plates’, which it hopes will harbour more nickel-copper sulphide mineralisation at depth.
St George currently has one set of drill rods spinning below 64 metres in its hunt for nickel copper sulphides within a 19,320 Siemens EM conductor modelled from an earlier drill hole to sit at around 350m downhole.
A separate drill hole in the current campaign has tagged 18.7m of intrusive-style volcanic rocks below 493.9m downhole, confirming a further 200m western extension of the Cathedrals Belt’s intrusive rock unit. A downhole EM survey is scheduled for the drill hole next week as the company nails down the strike of the Cathedrals Belt host rocks into its West End prospect area.
The westernmost drill hole in the current program set off fireworks with three DHEM conductors producing conductivity values of 69,926 Siemens, 27,000 Siemens and 32,235 Siemens, respectively.
St George Mining Executive Chairman, John Prineas said: “The science continues to support the potential for further significant mineralisation to be present in the large intrusive mineral system at the Cathedrals Belt.”
“It is very pleasing to therefore see the latest downhole EM survey data at Investigators and West End identify larger and more powerful EM plates than previous analysis had recognised.”
“Some of the new EM plates are located down-dip of known mineralisation at a depth that ground-based EM surveys are unlikely to have screened effectively. With very little drilling in this area, the new EM conductors are excellent targets for the potential discovery of nickel-copper sulphides at depth.”
Whilst the company’s geologists are pouring over the diamond core from its latest round of drill holes, its geophysicists have been playing with some fresh aeromagnetic and radiometric survey data on its 100 per cent-owned ground located some 30km north of Cathedrals Belt.
St George said the new high-resolution airborne magnetic data set confirms the presence of two distinct linear magnetic trends which cut across each other. Interestingly, one of the linear trends has the same strike as the Cathedrals Belt to the south.
Importantly, St George’s geologists swooped on the area and recovered soil samples and rock chips which were identified as mafic rocks with nickel-copper anomalism. The company said it has put boots back on the ground there to expand the soil sampling program along the bulk of the strike length of the linear magnetic feature.
Mr Prineas added: “We are also excited by the results of the new magnetic survey conducted over two of our 100%-owned tenements E29/972 and E29/1041. The strong features identified are similar to the magnetic signature of the highly mineralised Cathedrals Belt, giving encouragement that these new targets have potential to represent intrusive rocks with mineralisation. These targets will be drilled as soon as practicable.
With robust nickel and copper prices predicted well into the future, St George is now moving as quickly as it can to define the extents of what increasingly appears to be considerable nickel-copper sulphide mineralisation at Mt Alexander.
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By Matt Birney
