St George Mining Ltd (ASX:SGQ) survey work has delivered breakthrough results which have identified new exploration targets at its flagship Mt Alexander Nickel-Copper Sulphide Project in WA's north-eastern Goldfields.
A magnetotelluric (MT) and audio-magnetotelluric (AMT) survey, completed last month was designed to map structures and conductive rock types along two key sections of the Cathedrals Belt.
These sections are known to host nickel-copper sulphide mineralisation and the survey was undertaken to identify repetitions of similar structures and stratigraphy in the underexplored tenements adjacent to Cathedrals.
"Game-changer" for exploration
Interim results have confirmed exploration potential with the MT/AMT survey mapping structure and conductive stratigraphy to a depth of more than 3,000 metres from surface.
This potential is described by SGQ as being "very significant" and executive chairman John Prineas said the results were a game-changer for exploration at the project.
The deep faults are textbook conduits for nickel-copper sulphides and typical of large nickel sulphide mineral systems.
North to south cross-section of Cathedrals Belt showing MT/AMT 2D conductivity data
Investors responded positively with shares up as much as 30% to an intra-day high of 8.2 cents.
Prineas said: “We have already discovered high-grade nickel-copper sulphides at shallow depths across more than 5.5 kilometres of the Cathedrals Belt.
“However, intrusive mineral systems like we have at the Cathedrals Belt will typically have significant mineralisation at depth.
“These potential larger deposits are likely to be at deeper levels than explored to date at the Cathedrals Belt and our challenge has been how to best target drilling to discover these deeper, undercover deposits.”
Modelling of survey data continuing
New conductive features have been identified at depth within the Investigators, West End and Fairbridge prospects in areas yet to be tested by drilling.
Conductive structures and stratigraphy parallel to the Cathedrals Belt have been identified on Exploration Licence E39/548, to the north of the Cathedrals Belt.
The survey at the Cathedrals Belt has provided data to depths of more than 5 kilometres from surface, with highest resolution data returned for up to 1.5 kilometres from surface.
Modelling of the MT survey data is continuing with further results due next week and a revised drilling program is being planned to test the new deeper targets.
Drilling program to be revised
Prineas continued: “We will revise the drill program for Mt Alexander in light of this data and are very excited at the opportunity to test drill these new targets.
“The COVID-19 pandemic has created many challenges for our community and for our industry.
“We will carefully navigate this evolving period of uncertainty to protect the health and safety of our team and service providers and to keep St George strong.
“We are undeterred in our commitment to deliver further exploration success at our projects and will be announcing more significant exploration initiatives over the coming weeks, including a revised drill program for Mt Alexander and our first exploration results at the new Paterson project where an airborne magnetic survey was completed last month.
“The appointment of external geological consultants for a maiden resource estimate is another major step in the scoping study for the potential mining of the shallow deposits at the Cathedrals Belt.
“We are aiming to deliver an economically robust start-up mine with very low up-front capital costs and a high-value product with exceptional payabilities for nickel, copper, cobalt and platinum group metals that include palladium, platinum and rhodium.”
Scoping study advancing to a mine
St George has appointed Entech as its external geological consultant to estimate a JORC-compliant mineral resource at Mt Alexander as part of a scoping study.
This study will focus on assessing a potential mining operation that can be developed with very low capital costs and a simple open-pit mining operation.
The resource estimate will initially focus on Stricklands deposit where thick massive nickel-copper sulphide mineralisation starts at 30 metres below surface.
This is also considered to have the simplest potential mining operation among the four shallow deposits discovered so far across the Cathedrals Belt.
Metallurgical test-work with Strategic Metallurgy in Perth is continuing while test-work in Canada has been delayed due to travel and other restrictions.
Six diamond holes are planned for Stricklands to provide further samples for the ongoing test-work.