De Grey Mining Limited (ASX: DEG) has announced a highly encouraging update from the follow up aircore drilling at the Hemi Prospect within its Mallina Gold Project in WA.
The company reported that substantial thick and high-grade gold mineralisation were intersected on two discovery Sections A and B, 640m apart. DEG said that the mineralisation is open in all directions and at depth.
The company said that at Section A, drilling has defined a zone of 30m width @ 3.7g/t – 7.5g/t, defined to 100m depth. In Section B, DEG said that the drilling has defined a zone of +60m width, with all holes ending in mineralisation.
The company said that 50 holes from current program are awaiting assay results. De Grey reported that the step out aircore drilling is continuing and the RC and DD rigs are being mobilised.
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 1.7 Moz Mallina project hosts numerous large deposits. Significant gold deposits include Withnell, Mallina, and Toweranna. Other prospects include Hemi, Antwerp, and Scooby prospect.
Withnell is the largest gold resource at Mallina, currently hosting a combined open pit and underground resource of 4.65 million tonnes at 2.9g/t for 429,300oz of gold.
Aircore drilling program at Hemi
The company had recently commenced an aircore drilling program at the Hemi Prospect. The program was aimed at better defining the recent high-grade gold mineralisation (43m @ 3.7g/t Au and 25m @ 2.7g/t Au), on the 640m spaced sections as well as infilling lines to establish 320m x 80m spaced drilling.
DEG said that a total of 57 new holes (BWAC309 to BWAC365) completed for a total of 4709m to date.
The company announced that the initial results from the first 7 holes were completed on the two initial discovery Sections A and B of the Hemi prospect.
Further results remain pending for 50 holes including on the original Section A and step out lines along strike.
The company reported high-grade initial results from Section A and Section B of the Hemi prospect.
DEG reported that on Section A, the initial results from the infill aircore drilling was received for priority holes BWAC309, 310, and 315. Results for holes BWAC319-323 on this section are pending.
The company said that additional 1m resampling has also been completed on the original discovery hole BWAC245.
De Grey reported that the results to date define a substantial steeply south dipping zone of high grade gold mineralisation.
Significant intersections include 24m @ 7.5g/t Au from 126m in BWAC315, including 18m @ 8.6g/t (EOH); 49m @ 3.7g/t Au from 65m in BWAC309, including 18m @ 6.6g/t; and 36m @ 4.0g/t from 39m in BWAC245, including 11m @ 8.9g/t.
De Grey reported that on Section B, the initial results were received for priority holes BWAC311 -314. DEG said that additional 1m resampling has been completed on the original discovery hole BWAC258.
The company said that the results to date define a broad zone of gold mineralisation over at least 60m in apparent width in holes BWAC258, 312, and 313 with intercept grades ranging from 2.2g/t to 4.3g/t.
Significant hits include 24m @ 4.2g/t Au from 36m in BWAC312, including 10m @ 7.4g/t (EOH); 15m @ 2.5g/t Au from 33m in BWAC313 (EOH); and 21m @ 2.5g/t from 36m in BWAC258 (EOH).
Updates and next steps
De Grey’s reported that its regional and wide spaced aircore program aims to systematically test the various large prospective corridors throughout the project for new large-scale gold deposits.
The company said that the positive drill results at Hemi now provide a key focus for near term resource definition drilling. De Grey said that an RC and diamond rig are being mobilized to site to commence this deeper and more detailed drilling. The company said that this drilling will look to test deeper on the known sections and then step out on parallel sections 80m part.
De Grey reported that the aircore drilling will continue to test along the Scooby to Antwerp Structural Trend (SAST) during the March quarter to define additional resource drilling targets.
The company said that the Phase 1 of this drilling is nearing completion and will provide 320m x 80m coverage over a 2.5km strike length at Hemi. DEG said that the phase 2 aircore drilling program will then aim to extend this drilling a further 1.5km SW towards the Antwerp Prospect where other encouraging shallow gold mineralisation has been previously intersected.
DeGrey’s Technical Director, Andy Beckwith said: “For an exploration geologist, these results are both satisfying and exciting. Hemi’s shallow high grade gold zones provide an excellent opportunity to increase resources and further derisk our path to production.
The individual assays down hole are very robust creating solid high grade gold zones over considerable thicknesses which we expect to continue at greater depth. On Section A, drilling has defined a subvertical to south dipping 30m wide gold zone hosted in sediments. Section B shows a potential +60m wide gold zone in an intrusive with drilling yet to be completed below the oxide zone.
We currently interpret that the two mineralised zones are structurally related, suggesting we could be drilling a major new gold discovery. Aircore drilling will continue to define the lateral extent, orientation and potential scale of the mineralised system. Follow-up RC and diamond drilling will commence shortly with a view to establishing an initial inferred resource.”