Growth focused Western Australian nickel company St George Mining (ASX: SGQ) today reported ongoing positive exploration results at its flagship Mt Alexander project, located in the north-eastern Goldfields of WA.
30m thick mafic-ultramafic unit from 440.5m downhole intersected by MAD192 at the West End Prospect:
The interval includes a 6m thick ultramafic with disseminated nickel-copper sulphides from 465.5m downhole (<5% sulphides with pentlandite (pn), chalcopyrite (cp) and pyrrhotite (py)).
The mineralised mafic-ultramafic unit intersected by MAD192 has not been structurally modified – it is preserved, which supports the potential for the presence of nickel-copper sulphide deposits that are intact and unaltered.
The thick mafic-ultramafic unit is comprised of the same intrusive-style rocks that are known to host high-grade massive nickel-copper sulphides in other parts of the Cathedrals Belt.
49,000 Siemens electromagnetic (EM) conductor:
MAD192 pierced the target modelled plate for the 49,000 Siemens EM conductor identified from the downhole EM (DHEM) survey in MAD184 but did not intersect any conductive material that could explain the very strong conductor.
The 49,000 Siemens EM conductor remains untested and a significant exploration opportunity.
The intersection in MAD192 of a thick mafic-ultramafic unit with basal nickel-copper sulphides in the vicinity of the modelled plate is highly encouraging.
A DHEM survey is scheduled for completion on MAD192 later this week to acquire additional data and revise the modelling for the target conductor.
Drilling continues 24/7:
Second drill crew has arrived at Mt Alexander enabling drilling in two shifts 24/7.
MAD193 is underway to test the 16,200 Siemens EM conductor identified from the DHEM survey in MAD184.
These powerful EM conductors have an electrical signature consistent with massive sulphides and offer an excellent opportunity to discover new nickel-copper sulphide deposits in the underexplored western extension of the Cathedrals Belt.
Potential for a new discovery:
MAD192 was completed to a downhole depth of 500m to test a plate modelled with conductivity of 49,000 Siemens – being the modelled plate for one of two very strong conductors identified from the DHEM survey in MAD184.
The new conductors are within the West End Prospect, which covers the underexplored western extension of the Cathedrals Belt. They are located more than 800m to the west of previously intersected massive sulphides on the Cathedrals Belt and are the deepest conductors ever identified in the Cathedrals Belt.
The discovery of massive sulphides at this location would represent a new discovery that could extend the strike of mineralisation across the Cathedrals Belt to more than 6.3km.
MAD192 confirms a fertile target horizon:
MAD192 intersected a 30m thick mafic-ultramafic unit from 440.5m downhole. These types of intrusive rocks are known to host massive sulphide deposits in other parts of the Cathedrals Belt. The intrusive unit included a 6m interval of disseminated sulphides, which is a potential indicator of massive sulphides nearby.
MAD192 did not intersect any conductive material that could account for the 49,000 Siemens EM conductor, which is the deepest conductor detected so far along the Cathedrals Belt. A DHEM survey will be completed in MAD192 to provide additional data from which the location and geometry of the powerful conductor can be reviewed, and a further target plate modelled for drill testing.
The data from the DHEM survey in MAD184, which was used to model the new conductors, is considered very good. The two strong EM anomalies recorded in the data are high quality conductors that are interpreted to represent bodies of bedrock-hosted massive sulphide mineralisation.
John Prineas, St George Mining’s Executive Chairman, said:
“Drilling continues to intersect the large intrusive mineral system at the Cathedrals Belt, which we know hosts abundant high-grade nickel-copper sulphides at other points along the strike of the Belt.
“The mineral system remains open to the west where we are currently drilling to test new and very strong conductors. Significantly, the system is also unconstrained at depth towards the north-northwest down-dip of the system.
“The results in MAD192 have not altered the interpretation of the presence in this area of very strong EM conductors with the characteristics of massive sulphides.
“We are confident that ongoing drilling has outstanding potential to deliver another significant discovery of massive nickel-copper sulphides.”