Azure Minerals discovers new nickel-copper sulphide zone at Andover project

by Leena Thomas
Image: Azure Minerals Limited

Azure Minerals Limited (ASX: AZS) announced that the latest DD hole ANDD0004 intersected a new nickel-copper sulphide zone at the Andover Ni-Cu Project located in the West Pilbara region of Western Australia.

The company reported that ANDD0004 intersected a 38.1m-wide interval containing multiple zones of nickel-copper sulphide mineralisation from a downhole depth of 336.1m, including 6.10m from 347.50m of blebby to matrix Ni-Cu sulphides; 4.05m from 354.80m of massive Ni-Cu sulphides; and 4.10m from 359.20m of heavily disseminated grading to matrix and massive Ni-Cu sulphides.

AZS noted that massive nickel-copper sulphides mineralisation was intersected at the expected depth, confirming the source of the electrical signature of the new EM conductor.

Azure said that the diamond drilling is continuing with ANDD0005 underway to test for potential up-dip extensions with further holes planned to test down-dip and along strike. The company said that the downhole EM (DHTEM) surveying on completed holes is underway to better define the geometry of the large conductor intercepted in ANDD0004 and define off-hole conductors.

Andover nickel-copper project

The Andover nickel-copper project hosts nickel-copper sulphide mineralisation discovered by Creasy Group in 2018. It is located 35km southeast of Karratha and immediately south of Roebourne.

As per Andover Tenement Sale and Exploration Joint Venture Agreement, Azure has a 60% interest in the tenement EL 47/2481 and Exploration Licence Application 47/4314 from Croydon Gold Pty Ltd, a private subsidiary of the Creasy Group. The Creasy Group retains 40%.

FLTEM survey

Azure had completed FLTEM surveying of 12 separate geophysical anomalies located throughout the Andover project area in August 2020. Results and geophysical modelling confirmed the presence of numerous high-quality conductors that are interpreted to represent bodies of bedrock-hosted sulphide mineralisation, potentially containing nickel and copper sulphides.

One of the largest and most electrically conductive of these EM conductors was named VC7.

Diamond Drilling at Andover

The company had recently commenced diamond drilling at the Andover project, with 6 DD holes planned – ANDD0001, ANDD0002, ANDD0003, ANDD0004, ANDD0005, and ANDD0006.

Initial DD drilling comprised of three holes, ANDD0001, ANDD0002, and ANDD0003. It had returned several significant nickel-copper intersections. Highlights included ANDD0001: 39.7m @ 0.95% nickel and 0.52% copper from 81.6m, which included 3.9m @ 2.85% nickel and 0.47% copper from 94.5m; and 11.3m @ 1.21% nickel and 0.66% copper from 110.0m, which included 5.0m @ 2.09% nickel and 1.14% copper from 116.0m.

VC7 was located in the vicinity of the sulphide mineralisation recently drilled by Azure. Modelling of FLTEM data from four 600m x 600m survey loops, indicated that VC7 is a single conductor that strikes to the west-northwest for at least 1,050m and has a top to bottom extent of at least 150m-200m with a steep northerly dip.

Given its strong electrical conductance (5,000-6,000 Siemens) and proximity to the near-surface conductors and drilled sulphide mineralisation, VC7 immediately became a high priority drill target.

Outstanding results from DD hole ANDD0004

The diamond drill hole ANDD0004 was specifically designed to test the upper part of the eastern end of VC7 where FLTEM modelling provided the best definition of the conductor plate. The hole was predicted to intersect the plate between 350m-375m downhole.

Substantial Ni-Cu sulphide mineralisation

AZS reported that the DD hole ANDD0004 entered the sulphide zone at 336m and exited at 374m downhole.

The company said that the DD hole ANDD0004 drilled through a 38m-wide interval (true width not known at this stage) containing significant quantities of nickel and copper sulphide mineralisation in the form of massive, semi-massive, matrix, blebby and disseminated pentlandite (nickel sulphide), chalcopyrite (copper sulphide) and pyrrhotite (iron sulphide).

The summary drill log of mineralised intersections for ANDD0004 is as shown below.

AZS said that visually, the quantity of sulphide mineralisation in ANDD0004 is estimated to be significantly greater than was observed in Azure’s first three drill holes.

What’s next?

Azure reported that further work would include submitting drill core for analysis; additional diamond drilling to follow-up the sulphide intersections; and Downhole EM surveying.

AZS said that due to ANDD0004 intersecting substantial quantities of nickel-copper sulphide mineralisation associated with the VC7 conductor, drilling will continue and is targeting the up-dip and down-dip range. The company said that this will be followed by step-out drilling to the west-northwest to test the along-strike extent of VC7.

Azure said that the DD hole ANDD0005 is underway and will test the up-dip extension with a planned intersection point approximately 50m above the sulphide zone intersected in ANDD0004, and the following DD hole, ANDD0006, will test the down-dip extent approximately 50m below ANDD0004.

The company reported that downhole EM (DHTEM) surveying is being undertaken in each of the drillholes as they are completed, which will provide greater definition on the vertical / down-dip extent of the VC7 conductor plate.

AZS said that based on FLTEM surveying completed to date, 12 separate conductor anomalies were identified within the Andover project area. Drilling to test other high-priority conductors is being planned and, subject to drill rig availability, likely to commence in the first quarter of 2021.

Management statements

AZS’s Managing Director Tony Rovira said: “Given Azure’s recent success in our first three holes drilled at Andover (refer ASX: 9 November 2020) and the distribution of outcropping nickel and copper-rich gossans, we considered that the area to the west of our initial drilling was highly prospective.

This concept was supported when new surface FLTEM surveys identified a highly conductive and laterally very extensive east-west trending conductor that was interpreted to represent a substantial body of sulphide mineralisation. Geophysical modelling indicates this conductor lies beneath and is spatially separate from the anomalies targeted by our first three drill holes.

Diamond drill hole ANDD0004 targeted the eastern end of the new conductor about 150m-200m below the mineralisation intersected in the first three holes. The hole successfully intersected substantial quantities of nickel and copper sulphide mineralisation at almost the exact depth the modelling predicted the EM conductor plate to be located.The key point to take away from our drilling successes to date, is that wherever we have targeted an EM conductor at Andover, we have intersected nickel-copper sulphide mineralisation. The strongly mineralised intersection in ANDD0004 leads us to believe that if the one kilometre-long conductor plate is similarly mineralised throughout, there is excellent potential here for a major new nickel-copper deposit.“