St George Mining Limited (ASX: SGQ) has announced strong preliminary drill results from the Investigators prospect in the Mt Alexander Project, WA.
The company reported that hole MAD172 intersected 17.28m thick nickel-copper sulphides from 242.5m downhole.
SGQ said that the style of mineralisation intersected is consistent with mineralisation remobilised from a larger and proximal source of nickel-copper sulphides.
The company noted that MAD172 intersected nickel-copper sulphides approximately 125m north-west and downdip of previous known mineralisation in MARC109.
SGQ reported that hole MAD172 establishes a substantial down-plunge extension of high-grade mineralisation with thickness and grade increasing at depth. The company said that DHEM survey would be completed in MAD172 to search for additional mineralisation around the hole.
It may be noted that MAD172 was planned to test the deepest conductor drilled to date at the Cathedrals Belt, further supporting the potential for significant mineralisation in the down-dip direction of the highly mineralised Cathedrals Belt.
Mt Alexander project
The Mt Alexander Project is located 120km south-southwest of the Agnew-Wiluna belt which hosts numerous world class nickel deposits.
The project is comprised of five granted Exploration Licences, E29/638, E29/548, E29/954, E29/962, and E29/972. The project contains advanced prospects like Investigators (MAD60), Stricklands (MAD71), and Cathedrals (MAD56), which are located on E29/638.
Mt Alexander has two stand-out EM anomalies named Radar and Bullets prospects. Other unexplored areas in Mt Alexander project includes the West End and Fish Hook prospects.
EM conductors identified
The company had identified seven electromagnetic (EM) conductors by the downhole EM (DHEM) surveys in the recently completed deeper stratigraphic holes along the Cathedrals Belt.
Drill hole MAD172 was completed at Investigators prospect to test the first of the seven electromagnetic (EM) conductors identified so far.
The company noted that the EM plate targeted by MAD172 is modelled with conductivity of 25,000 Siemens and was predicted to be intersected at 260m downhole.
Thick nickel-copper sulphide intersections
St George Mining reported that deeper drilling of areas peripheral to the strong surface EM data, including MAD172, has now confirmed that significant mineralisation continues at depth.
SGQ reported that MAD172 intersected thick nickel-copper sulphides from 242.5m to 259.78m downhole.
For MAD172, the style of mineralisation at interval of 242.5m to 253.5m was found to be ultramafic with disseminated sulphides and blebby sulphides (2mm-3mm) increasing with depth (5-10% sulphides comprising pentlandite (pn), chalcopyrite (cp) and pyrrhotite (po)
For MAD172, the style of mineralisation at interval of 253.5m to 259.78m was found to be ultramafic with heavily disseminated sulphides and larger blebby sulphides (5mm- 65mm) (20-30% sulphides comprising pn, cp, po)
Potential for stronger mineralisation
SGQ said that the disseminated and blebby sulphides intersected by MAD172 are consistent with mineralisation found close to massive sulphide deposits, supporting the potential for more substantial mineralisation nearby.
The company said that the high conductivity of the EM plate is not fully explained by the style of mineralisation intersected by MAD172, further suggesting potential for stronger mineralisation proximal to the hole.
DHEM survey in MAD172
St George Mining said that a DHEM survey will be completed in MAD172 later this week, and follow-up drilling will be prioritised after review of the survey data.
The company reported that the diamond drilling is continuing with MAD173 currently in progress at Investigators. SGQ said that this hole is planned to a depth of 270m and will test a DHEM plate modelled with conductvity of 10,000 Seimens.
The company said that further exploration will be planned based on ongoing drill results, geophysical surveys and geological assessment of prospectivity.
St George Mining’s Executive Chairman John Prineas said: “Deeper drilling has already confirmed significant down-plunge extensions of the mineralised ultramafic and now – with MAD172 – we have seen the deepest intersection of nickel-copper sulphides at the Cathedrals Belt to date.
The thickness of the mineralised intercept and the style of mineralisation support the potential for further high-grade mineralisation to be present in this area.
Under the intrusive geological model for the Cathedrals Belt, the larger deposits of mineralisation are likely to be at deeper levels than explored to date, so it is very exciting to see the thickness of nickel copper sulphides increasing with depth.
We are increasingly confident that ongoing drilling could discover further significant nickel-copper sulphides down-plunge of the shallow high-grade deposits already established at the Cathedrals Belt.”