Diamond drilling has confirmed significant mineralised gold system is present at Great Southern’s Southern Star project within Western Australia’s Duketon greenstone belt.

Two diamond holes drilled to increase its geological understanding both intersected the target mineralised quartz dolerite unit and significant gold bearing assemblages were noted as part of a potentially larger system along with a standout intersection of 20m grading 1.7 grams per tonne (g/t) gold from 62m including 1.6m at 13.2g/t gold from 76.6m.

Previous drilling by Great Southern Mining (ASX:GSN) had returned a high-grade intercept of 17m grading 7g/t gold including 1m at 109g/t gold about 200m south of the previously known extent of mineralisation.


First visual

“The structural analysis of the diamond core has given GSN the first visual insight to what the gold mineralisation looked like in core and what structural and alteration assemblages are key for future targeting,” Executive chiarman John Terpu said.

“The results clearly demonstrate the significance and potential of the deposit given the noted similarities of mineralisation to the much larger million-ounce open pit and underground gold mine at Rosemount and to the Ben Hur Deposit, both along strike on the same regional mineralised structure.

“We remain very excited at the potential of Southern Star and the wider Duketon Gold Project for continued exploration success.”


Southern Star burns bright

Gold mineralisation at Southern Star is associated with quartz veining and sulphides and hosted in an east-dipping quartz-dolerite unit that is about 80m

The two diamond holes – drilled 580m apart at opposite ends of the current known mineralisation – targeted the footwall of the quartz dolerite unit as this is where the primary lode is persistent and of high-grade based on assessment to date.

This high-grade mineralisation can be traced for over 700m of strike length and is open in all directions.

Diamond hole 21SSDD001 intersected a wide zone of multi-phased quartz veining from 56.6m to 80m. Logging of the core found that intense albite alteration with hydrothermal veining correlates well with the area of high-grade gold intervals.

Bismuth, a known magmatic pathfinder, appears to correlate well with the zone of logged albite alteration while arsenic appears to correlate well with the sericite/brown mica alteration that was observed deeper downhole and which also correlates to a secondary zone of gold mineralisation.

Great Southern expects the new understanding of alteration assemblages and pathfinder elements will be key in vectoring in on the high-grade mineralisation at Southern Star.

The second diamond hole intersected similar alteration assemblages though these were not as intense while the wide zone of quartz veining was also absent.

Multi-element analysis is being undertaken on both diamond holes.


Next steps

The company notes that the reverse circulation rig will immediately return to Southern Star to test for strike extensions with a focus on the south where no deep drilling has taken place.

Drill targeting will be refined by a four-day litho-structural review by Outcrop Exploration that was carried out alongside the diamond drilling.

This article was developed in collaboration with Great Southern Mining, a Stockhead advertiser at the time of publishing. 

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.