Special Report: Drilling continues to extend the size of the Brolga zone within De Grey Mining’s exciting Hemi discovery in the Pilbara.

Just days after increasing resources at the broader Mallina gold project by 29 per cent to 2.2 million ounces, ongoing drilling at the ‘game-changing’ Hemi discovery has increased the size of the Brolga zone by a further 220m to +560m long, up to 300m wide and up to 300m deep.

To top it off, De Grey (ASX:DEG) added that new sediment-hosted gold mineralisation has been intersected in the hanging wall and footwall positions, providing additional potential.

Notable results from the latest Brolga drilling included 100.4m grading 2.8 grams per tonne (g/t) gold from a depth of 104m including 16m at 2.6g/t gold from 104m and 51.9m at 3.2g/t gold from 146.4m, 27m at 2.1g/t gold from 71m, 67m at 1.4g/t gold from 129m.

Meanwhile, the drilling of both the footwall and hanging wall sediments returned 20m at 3.4g/t gold from 56m including 4m at 12.5g/t gold and 3.9m at 11.2g/t gold from 221.6m including 0.4m at 97.3g/t gold.

Plan view of drilling at the Brolga zone
Plan view of drilling at the Brolga zone Pic: Supplied

The company said the results enhanced the potential for a large tonnage open pit style bulk mining opportunity.

It is worth noting that no resource has been estimated for Hemi at this stage and the continued drilling success to date bodes well for its future inclusion into the broader Mallina resource.

Hemi will boost the overall ounces hosted at Mallina significantly but the question is by exactly how much.

Argonaut analyst Matthew Keane estimated in late March that just the combined Brolga and Aquila zones at Hemi could already host 2.8 million ounces of gold.

That was not including any of the results that have been announced to the market since then.

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Commenting on the latest results from Brolga, exploration manager Phil Tornatora said: “Mineralisation remains open in most directions at Brolga and now we are seeing gold in the adjacent sediments as well.

“Drilling is providing more detail on the deposits, possibly showing a large-scale SW plunge to mineralisation at Brolga.

“Many holes have encountered broad gold zones that have finished in gold mineralisation and remain open. Drilling will continue to focus on extensions to the SW, NE and at depth.”

Further reverse circulation and diamond drilling is planned for Brolga after De Grey completes priority holes at the Aquila zone and initial testing of the area of aircore drilling north of Aquila.

An update on these initiatives is anticipated after Easter.

Hemi was discovered in mid-December 2019 under a shallow ‘blanket’ of transported cover.

Since then, drilling has provided compelling support for the company’s theory that its rapidly growing — but grossly underexplored —2.2Moz Mallina project hosts numerous large deposits.




This story was developed in collaboration with De Grey Mining, a Stockhead advertiser at the time of publishing.
This story does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.