Best ever intercept of nickel-copper sulphides at investigators
Emerging Western Australian nickel company St George Mining Limited has announced an outstanding intersection of nickel-copper sulphides at the Investigators Prospect within the Mt Alexander Project, near Leonora in the north-eastern Goldfields.
John Prineas, St George Mining’s Executive Chairman, said: “The intersection in MAD126 is shaping up as our best ever at the Investigators Prospect.
“This is a particularly exciting intercept as there are strong conductors located up-dip and down plunge of the massive sulphides identified by MAD126, giving us confidence that drilling will intersect more massive sulphides in what we believe may be a significant channelised flow.
”Our drilling is continuing to scope out the scale of the discovery at Mt Alexander with MAD126 another outstanding result that has extended the footprint of high-grade mineralisation.”
Drill hole MAD126 is positioned on the MAD111 Line being drilled at the Investigators Prospect, located on the Cathedrals Belt where exploration by St George has established a 4.5km strike of high-grade nickel-copper sulphide mineralisation.
MAD126 was completed to a downhole depth of 209.9m to test EM conductor MAD120b: X1, which was modelled with a conductivity of 210,000 Siemens.
Sulphide mineralisation was intersected in MAD126 between 177.5m to 191.87m downhole, including massive sulphides from 185m to 190.25m, in the position modelled by Newexco.
MAD126 is down plunge of the previously intersected mineralised ultramafic on the MAD111 Line and confirms a significant 200m down dip extent to the known mineralisation on this line.
The MAD111 Line is located approx. at 231475E within the Investigators Prospect on the Cathedrals Belt.
Strong off-hole conductors – with conductivity ranging from 188,000 Siemens to 250,000 Siemens – have been identified on the MAD111 Line from downhole EM (DHEM) surveys, as announced in our ASX Release dated 3rd October 2018 Downhole EM Lights Up Strong Conductors at Investigators Prospect.
These conductors have similar geophysical properties to MAD120b: X1. The limits of these strong conductors remain open (in most directions). Modelling of the conductors will be revised with further drill hole data and DHEM survey data being acquired.
The ongoing intersection of high-grade mineralisation on this section together with the presence of strong conductors indicates a down plunge strike of mineralisation of some 200m on the MAD111 Line.
This is interpreted to represent a significant channelised flow with potential for further continuation of massive sulphide mineralisation.
MAD125 was completed to a downhole depth of 210m to test conductor MAD120b: X1. The drill hole deviated from its planned trajectory and is interpreted to have pierced the eastern edge of the target plate.
MAD125 intersected mafic and ultramafic rocks between 182m to 189.47m downhole with minor disseminated and blebby sulphides between 187m to 189.42m.
MAD126 was drilled as a vertical hole into MAD120b: X1 and successfully intersected massive sulphides.
Drilling of MAD127, to test for an extension of the MAD126 massive sulphide mineralisation to the south south-west, is underway. DHEM surveys are scheduled for the abovementioned drill holes once MAD127 is completed.
Based on the intersection angle of the drilling with the modelled ultramafic unit, downhole widths are interpreted to be close to true widths.
Nickel and copper values shown above are based on portable XRF analysis. They are preliminary in nature and a conclusive determination of the nickel, copper, cobalt and PGE values of the sulphide mineralisation will be confirmed when laboratory assays are available.
Average XRF readings in the massive sulphide interval are based on at least four readings per metre and are not length and density weighted. Metal content for intervals of disseminated sulphides are not accurately determined by portable XRF analysis and estimates for this style of mineralisation are based on geological logging.