De Grey Mining Limited (ASX: DEG) announced that the latest drilling at the Hemi Gold Discovery within its Mallina Gold project in Western Australia has resulted in the rapid growth of known mineralisation at Falcon intrusion, which is currently at 80m wide, +800m long, +250m deep and growing.
The company reported that the best intersections from the RC and diamond drilling include 42m @ 5.2g/t Au from 47m incl 31m @ 6.6g/t Au from 50m; and 50m @ 3.3g/t Au from 50m incl 29m @ 4.6g/t Au from 50m.
DEG said that the RC and diamond resource drilling confirm broad gold mineralisation previously identified in aircore drilling. The company said that the initial resource drilling now covers 800m strike and up to 250m depth. De Grey said that a further 2km of strike identified in aircore drilling remains to be tested. Mineralisation remains at depth and along strike.
De Grey reported that the recent aircore drilling extends the Falcon intrusion 500m to the south, providing an overall 3km of strike and remains open. The company said that the intrusion is widening to the south though less mineralisation is noted in logging.
Significant new results from aircore drilling to date include 1m @ 2.6g/t Au from 92m; and 4m @ 1.1g/t Au from 64m.
The company announced that the priority drilling programs going forward are focused on initial testing of the 3km strike potential at Falcon with RC drilling and deeper diamond drilling to define the mineralised footprint prior to infill resource drilling; extensional and infill drilling at Crow and Aquila; and aircore drilling at South Brolga and other regional intrusion targets.
Mallina gold project
De Grey’s Mallina Gold Project is located approx. 60km south of Port Hedland in the Mallina Province of Western Australia.
The project hosts numerous large deposits, of which significant gold deposits include Withnell, Mallina, and Toweranna. Other prospects include Hemi, Antwerp, and Scooby. Hemi is surrounded by world-class infrastructure within a Tier 1 mining jurisdiction.
Hemi is a discovery under 30m of transported cover, with two zones of strong, broad sulphide rich alteration with high-grade gold mineralisation partially defined in the Aquila and Brolga zones. De Grey had recently defined a third gold in bedrock zone called the Crow zone located immediately adjacent and north of the Aquila zone.
DEG’s drilling west of Brolga and south of Aquila delineated a highly brecciated and extensively sulphide altered subvertical intrusion. This new intrusion has been named Falcon and is located approximately 600m west of Brolga and immediately south of Aquila deposit.
Drilling at Hemi
De Grey had recently commenced step out RC drilling, diamond drilling, and aircore drilling at Hemi discovery.
The company said that the step out RC and diamond drilling results show continued robust and broad zones of gold mineralisation up to 80m wide, +250m down dip with over 800m strike, with mineralization remaining open.
DEG said that the early stage aircore drilling has extended the Falcon intrusion 500m to the south, providing an overall 3km of strike which remains open.
High-grade results from RC and diamond drilling
De Grey reported that the RC drilling is currently underway testing along strike to the south on a nominal 80m x 80m step out basis. Over 2km of strike remains to be RC and diamond drill tested.
The company said that the diamond drilling of hole HERC236D on section 7691800N intersected encouraging highly brecciated and sulphide altered intrusion from the bottom of the RC pre-collar at 226.6m to 281m with the hole finishing at 330m.
This hole is targeting mineralisation at depth below the previously reported intersections of 16m @ 3.7g/t Au from 43m in HERC141 which ends in mineralisation and 31m @ 1.3g/t Au from 88m in HERC234. Assays remain pending for this diamond core hole.
Previously reported high-grade results included 7691960N 66m @ 1.1g/t Au from 114m in HERC253; 51m @ 1.5g/t Au from 205m in HERC254D ends in mineralisation; 7691880N 31m @ 1.5g/t Au from 211m in HERC261D (incl 5m @ 4.1g/t Au from 232m); 7691720N 92m @ 1.3g/t Au from 167m in HERC233D; 58m @ 2.1g/t Au from 64m in HERC232; 16m @ 3.7g/t Au from 43m in HERC141 ends in mineralisation; and 7691640N 11m @ 1.2g/t Au from 199m in HERC231
Significant new RC and diamond drilling results to date include 7691560N 25m @ 2.2g/t Au from 124m in HERC256 (incl 5m @ 3.7g/t Au from 142m); 7691480N 2m @ 3.6g/t Au from 58m in HERC258; 3m @ 2.6g/t Au from 147m in HERC271; 7691400N 42m @ 5.2g/t Au from 47m in HERC260 (incl 31m @ 6.6g/t Au from 50m); 62m @ 1.5g/t Au from 143m in HERC262; 7691320N 50m @ 3.3g/t Au from 50m in HERC265 (incl 29m @ 4.6g/t Au from 50m); 17m @ 1.2g/t Au from 119m in HERC265; and 7691240N 12m @ 2.7g/t Au from 52m in HERC267 (incl 3m @ 7.6g/t Au from 52m).
AC drilling extends footprint of the intrusion
The company announced that aircore drilling at Falcon has extended the footprint of the intrusion a further 600m to the south. DEG said that the intrusion appears to be widening, though less potential mineralisation is noted in logging. De Grey said that further assay results are pending.
DEG reported that a further intrusion has been noted to the west of the southern tip of Falcon with assay results pending.
Significant new results from aircore drilling to date include 7690840N 1m @ 2.6g/t Au from 92m in BXAC530; and 7690680N 4m @ 1.1g/t Au from 64m in BXAC548.
Similar dimensions to Aquila
De Grey said that at Falcon intrusion, the bedrock mineralisation is covered by approximately 30m to 40m of transported material, similar to the Aquila, Brolga, and Crow deposits.
The company said that the mineralisation is intimately associated with highly brecciated and extensively sulphide altered portions of the north south orientated subvertical intrusion. DEG said that the style and intensity of alteration and brecciation are similar to the nearby Aquila deposit.
What’s next?
DEG announced that follow up aircore drilling will be undertaken to test for strike extensions to mineralisation. The company said that the programs of follow up RC and diamond drilling aimed at extending resources at depth and laterally are underway.
Management comments
De Grey Technical Director Andy Beckwith said: “The new results combine to define strong and robust gold mineralisation up to 80m wide, over 800m of strike and greater than 250m depth with mineralization remaining open.
Aircore drilling continues to extend the intrusion to the south with step out RC drilling continuing to systematically test along this 3km long target.The known mineralisation at Falcon has grown rapidly to 800m strike length and now has similar dimensions to Aquila.”