St George Mining uncovers more EM conductor targets at Mt Alexander

St George Mining Limited (ASX: SGQ) has announced further outstanding exploration results from its flagship Mt Alexander Project in WA.

The company reported that multiple EM anomalies were identified at West End Prospect by high temperature SQUID MLEM survey.

SGQ said that the Downhole electromagnetic (DHEM) surveys at Investigators prospect recorded multiple new EM anomalies.

The company announced that Magnetotelluric (MT) survey will commence shortly at Mt Alexander. The data from the MT survey is anticipated to assist in planning deeper drilling at the Cathedrals Belt to further investigate the down-plunge extensions of the shallow nickel-copper sulphide deposits in the Belt.

SGQ also announced multi-rig drill programme to test large number of EM targets. The company said that the metallurgical testwork is in progress.

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 include the West End and Fish Hook prospects.

SQUID MLEM survey identifies many EM anomalies

The company announced that it has completed the SQUID MLEM survey over key target areas of the Cathedrals Belt.

SGQ said that the survey successfully identified multiple new EM anomalies in a number of areas that are prospective for nickelcopper sulphides.

West End Prospect

The company said that the recently completed SQUID MLEM survey over the West End Prospect has recorded a number of anomalous EM responses that are co-incident with the interpreted ultramafic trend.

The EM anomalies are situated to the north-northwest of the high-grade discoveries at Investigators where similar EM anomalies were recorded.

The company said that new West End EM targets may represent the downplunge continuation of the Investigators nickel-copper sulphide deposits.

Importantly, one of the off-hole EM anomalies detected in the DHEM surveys is broadly co-incident with a large EM anomaly identified in the surface MLEM data. This adds weight to the potential of the new EM anomalies to represent the down-plunge continuation of the Investigators nickel-copper sulphide deposits.

Fish Hook prospect

The company reported that SQUID MLEM EM anomalies were identified at Fish Hook prospect. SGQ said that the new EM anomalies are also proximal to the large nickel and copper soil anomaly identified at Fish Hook.

The soil anomaly strongly supports the presence of nickel-copper sulphides at Fish Hook.

Investigators prospect

The company said that at Investigators prospect, many EM anomalies are situated between 50m to 100m from known occurrences of nickel-copper sulphides, and represent an excellent opportunity to add significant volumes of sulphides to the known mineralisation at Investigators.

DHEM survey completed

St George Mining reported that DHEM surveys have also been completed in the deeper holes drilled at Investigators prospect in late 2019.

SGQ said that the DHEM surveys in two of the holes – MAD170 and MAD172 – have identified off-hole EM anomalies down plunge of the known mineralisation. One of the DHEM anomalies is also broadly coincident with an EM anomaly identified from the surface SQUID MLEM survey.

The company said that several off-hole EM anomalies were recorded, giving confidence for further down-plunge extensions of the shallow deposits at Investigators.

Drilling in March 2020

SGQ reported that the modelling of the new EM targets is being finalised, with drilling scheduled to commence in early March 2020.

MT survey

St George Mining announced that an MT survey is scheduled to be completed prior to the start of drilling in early March 2020. The survey measures the electrical and magnetic fields in the Earth’s sub-surface from which geological structures and rock types can be mapped.

The company said that the MT survey will encompass approximately 15km of the east-west strike of the Cathedrals Belt and will also cover the entire area of the Exploration Licences adjacent to the Cathedrals Belt. The MT survey will be designed to see upto 5km below the Earth’s surface.

SGQ said that the data acquired by the MT survey at Mt Alexander is expected to show the orientation of the intrusive stratigraphy and host structures at depth, and whether these continue uniformly at depth or are folded, stacked or otherwise disrupted.

This will assist in designing drill holes to investigate the potential for deeper nickel-copper sulphide deposits.

Updates and next steps

The company reported that it would be continuing the metallurgical testwork on the Mt Alexander mineralisation. It may be noted that the preliminary testwork from 2016 had identified high values of Palladium and Rhodium within the PGEs reporting to the nickel concentrate.

The preliminary test work produced a nickel concentrate that included 13.5g/t PGEs, including 9g/t Palladium and 1.2g/t Rhodium

SGQ expressed confidence that the testwork will further investigate the potential to commercialise these highly valuable metals within the company’s mineralisation.

2020 drilling programmes

St George Mining reported that it would be commencing its 2020 drill programmes shortly.

The initial drilling is envisaged to encompass: drilling of EM anomalies and geological/geochemical targets (Fish Hook prospect); drilling of EM anomalies and geological targets (West End prospect);  deep drilling underneath the numerous surface gossans (Fairbridge prospect); drilling of EM anomalies and geological targets (Radar prospect); drilling of EM anomalies and deeper geological targets (Investigators prospect); and resource definition drilling as well as metallurgical and geotechnical holes (Stricklands prospect)

RC rig and diamond rig

SGQ said that a combined reverse circulation (RC) and diamond drill programme will commence shortly.

The company said that a reverse circulation (RC) rig is scheduled to arrive at site in early March 2020. The rig will initially complete pre-collars for the deep diamond drill holes, and will then focus on drilling shallow EM targets and the resource definition drill-out of Stricklands.

The company reported that the diamond rig is scheduled to also arrive at site in March 2020 to commence drilling of deeper EM and geological targets. SGQ said that diamond drilling of deeper targets is preferred at the Cathedrals Belt as the hard, granite terrain is challenging for the percussion-drilling of the RC rig.

The company said that in addition to the new West End EM anomalies and deep DHEM anomalies at Investigators, drilling will test new EM anomalies at the Fish Hook Prospect and over 30 EM anomalies at the Investigators Prospect that were identified in 2019 and remain untested by drilling

St George Mining announced that further exploration will be planned based on ongoing drill results, geophysical surveys, and geological assessment of prospectivity.

Management statements

St George Mining’s Executive Chairman, John Prineas said: “EM surveys are the ‘go to’ targeting tool for nickel sulphide exploration – and these surveys have worked brilliantly at the Cathedrals Belt with all conductors drilled to date confirmed as nickel-copper sulphides.

Our 2020 exploration programme commenced with further EM surveys at Mt Alexander. We have methodically completed a new surface-based SQUID MLEM survey as well as DHEM surveys in recently drilled deeper holes.

The results are highly encouraging with new EM anomalies identified at the unexplored Fish Hook and West End Prospects, and new DHEM anomalies identified from the deeper holes at the highly mineralised Investigators Prospect.

The quantity of EM targets and their position in prospective geological locations provides confidence that ongoing drilling will deliver more discoveries of nickel-copper sulphides in the Cathedrals Belt.

We are also continuing the scoping study for a potential mining operation at Mt Alexander and are very pleased to be commencing resource definition drilling at Stricklands.

Metallurgical test work with industry leading metallurgical advisers is also progressing and we are keenly awaiting results on how to optimise the commercialisation of our high grades of nickel, copper, cobalt and platinum group metals – mineralisation which we believe is unparalleled amongst nickel developers.

Our 2020 work programmes for Mt Alexander are gaining momentum and we look forward to a very exciting year for St George shareholders.”

Written By Jonathan Norris
Jonathan is a founder of and has been covering the resources industry since 2018. With over 17 years experience in print, broadcast and online media, Jonathan has seen first hand the transformative effect of online niche media.