Further investigation of ground that may cover an extension of the geological structure that hosts the world’s largest hard-rock lithium mine is now in prospect for Galan Lithium after the company reported positive indicators from a site visit to its Greenbushes South property in WA’s south-west. The field work followed an earlier favourable review by Galan of historical exploration data.
The company, whose Managing Director JP Vargas de la Vega is about to get on a plane to Argentina to oversee critical work on its world-class Hombre Muerto West project in South America’s Lithium Triangle, has 80 per cent of Greenbushes South in a joint venture with ASX-listed Lithium Australia.
The latter picked up the ground adjoining the major Greenbushes lithium mine to probe the estimated 50km of Donnybrook-Bridgetown Shear in the 353sq.km Greenbushes South tenure.
Lithium Australia says the Donnybrook-Bridgetown Shear Zone, or “DBSZ” controls pegmatite emplacement at Greenbushes.
ASX-listed mid-tier miner IGO stumped up $1.4 billion earlier this year for a 49 per cent stake in Greenbushes operator Tianqi Lithium Energy Australia – giving it 25 per cent of Greenbushes and 49 per cent of Tianqi’s Kwinana lithium processing plant south of Perth.
Greenbushes, about 200km south of the WA capital, accounts for 40 per cent of the world’s current lithium supply. The site where tin and tantalite mining started in the 1890s has been one of Australia’s longest continuously operated mines.
Galan says the huge Greenbushes South project area starts about 3km south of the current Greenbushes open-pit mine, which now produces only lithium.
Its earlier review of historical data sets indicated a “well-defined footprint of anomalous concentrations of pathfinder elements surrounding the Greenbushes mine and along its host structure”, the DBSZ.
Galan’s first field mapping and rock and soil sampling since striking the JV deal with Lithium Australia in January this year was aimed at identifying and mapping the surface expression of the DBSZ.
Management says the north-south trending, steeply-dipping shear zone linked to syntectonic emplacement of Greenbushes’ lithium-bearing pegmatites has been recognised in geophysical data for the Greenbushes South area. The new mapping “helped identify its surface expression through the Greenbushes South project”.
Galan says 25 soil samples and 15 rock chip samples were taken perpendicular to the strike of the DBSZ. Assays for samples taken from near the DBSZ surface expression have shown arsenic concentrations up to 574 parts per million, antimony up to 16ppm antimony and tin up to 12ppm.
Other samples taken from previously mapped pegmatite outcrops were said to have concentrations of up to 27ppm tin.
Galan says the samples offer up a “positive sign for future targeted soil and geophysical surveys along the DBSZ to help identify potential blind pegmatite bodies”.
Planning for further soil and rock chip sampling is under way.
Greenbushes South gives Galan a potential counterweight to its significant emerging brine lithium project on the other side of the world.
The company’s 2020 preliminary economic assessment on Hombre Muerto West in Argentina’s north outlined a long-life, 20,000 tonnes per annum lithium carbonate project with a global first-quartile operating cost profile that could generate huge margins and rapid capital payback at current lithium carbonate prices.
Hombre Muerto West hosts resources of about 2.3 million tonnes of lithium carbonate-equivalent at an average 946 milligrams per litre lithium and a “total inventory” of about 3Mt LCE at 858mg/l Li.
Galan has 15 months and about $10 million of reserve drilling, pilot plant testwork and other feasibility study work ahead of it in Argentina.
As with the Lithium Triangle, Galan could not hope to be in a better lithium neighbourhood in WA than Greenbushes.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
By Matt Birney
