Special Report: De Grey’s infill gold drilling to enable robust resource estimation at the Brolga zone in Western Australia is off to an encouraging start.

The initial phase of drilling at 80m by 40m spacing has successfully demonstrated remarkable consistency within holes and strong continuity of mineralisation between holes.

Additionally, extension drilling has intersected further gold mineralisation to the northeast while follow-up drilling at the Brolga South intrusion has defined more mineralisation.

De Grey Mining (ASX:DEG) technical director Andy Beckwith said the results provided strong support and confirmed the company’s expectations of consistent and continuous gold mineralisation at the Brolga Zone within the Hemi discovery.

“The infill drilling program will continue over the coming months at all the Hemi zones to enable a robust resource estimate targeting a high level of JORC 2012 Indicated category resources by the middle of 2021,” he added.

“The Brolga South intrusion is becoming a strong target as it narrows and remains open to the south. Overall, the intrusion appears to parallel the new Falcon intrusion making the southern extensions a prime aircore drilling target.”

Indicated resources have sufficient information on geology and grade continuity to support mine planning.

infill gold drilling
Drilling location plan showing the new strike extension to the north east of Brolga and significant aircore and RC drilling results Pic: Supplied

Infill drilling returns consistent gold hits

Notable results from the infill drilling program to provide additional drill density and enable a robust indicated resource estimate include 81m at 1.7 grams per tonne (g/t) from a depth of 37m and 46m at 2.7g/t gold from 43m.

Extension drilling to the northeast returned a 23m hit grading 1.1g/t gold from 50m with mineralisation remaining open while the follow-up drilling at Brolga South hit 7m at 5.4g/t gold from 163m.

Infill drilling is continuing and De Grey notes that Brolga South extensions also remain a high priority due to their resemblance to the parallel Falcon zone just 500m to the west.

Discovered immediately south of the Aquila prospect, Falcon is 1.8km long and features up to 80m thick new altered intrusion 200m below surface that remains open to the south and at depth.

Metallurgical diamond drilling is also underway at Brolga to provide additional infill drilling and core material to determine communition and detailed sulphide flotation test work.


This article was developed in collaboration with De Grey 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.