Australia

De Grey Mining confident Hemi gold discovery has tier-1 production potential

De Grey Mining Limited (ASX:DEG) is Australias fastest-growing gold company, with the recent Hemi discovery in Western Australia and strong newsflow reflected by their market cap which is now around A$1 billion.

The Hemi discovery sits within the Mallina Gold Project and is a new style of mineralisation in the Pilbara region – intrusion-hosted, large-scale and close to the surface with grade continuity. It is also is largely underexplored with district-scale upside.

Relatively unexplored


While it has the same geological setting as the Yilgarn Craton, which has a very mature exploration history of more than 120 years, the Pilbara Craton has only been actively explored for the last 20 years.

The company is confident the region could host new shallow discoveries, unlike in the Yilgarn where new discoveries are only expected at depth.

This represents a significant opportunity for De Grey with the immediate growth strategy linked to increasing gold resource, extending deposits, and making more Hemi-like discoveries close to established mining infrastructure in the region.

Hemi gold system


The Hemi system consists of three main deposit areas – Brolga, Aquila and Crow.

Large potential extensions to Aquila and Brolga have been identified from drilling with four rigs currently drilling extensional targets.

At Aquila, results include 33 metres at 1.5 g/t with the potential to extend the strike by 50% to more than 1,200 metres.

At Brolga, new extensions were recently reported with results from aircore drilling of 16 metres at 2.4 g/t with the southern extension currently around 1,000 metres long by about 200 metres wide and open.

Further aircore results are pending while more RC drilling is planned at both deposits.

At Crow deposit, the company is targeting an area up to 400 metres wide and 1,000 metres of strike with RC drilling planned and early-stage step-out drilling underway.

The company believes that further drilling will determine the scale of any future open pit mine which may have significant operating cost benefits.

Further drilling will determine the scale of any future open pit mine which may have significant operating cost benefits.

Brolga recoveries


Initial metallurgical test-work on Brolga mineralisation achieved recoveries of:

  • 96.3% from fresh rock using flotation, oxidation and carbon in leach (CIL); and
  • 93% in oxidised using CIL.

Results from a broader metallurgical test-work program are expected later in the current quarter.

Finding the next Hemi


De Grey has identified four lookalike mineralised intrusions within 10 kilometres of Hemi called Scooby, Antwerp, Shaggy and Alectroenas.

Two rigs are testing targets at Scooby and Antwerp and a detailed aeromagnetic survey has been completed over the prospective 30-kilometre zone.

Modelling, interpretation and a targeting study are well advanced and the company is now in the position to accelerate drill testing.

Regional intrusions


A total of eight known intrusions have been identified throughout the overall project area and seven are mineralised. Four of these are mineralised in the Hemi corridor.

More than 20 new magnetic features have beeRead More – Source