Askari Metals’ soil auger drilling at its Callawa project, about 85km north-east of Marble Bar in Western Australia’s East Pilbara region, has yielded significant nickel-copper-cobalt mineralisation, with a top value of 1808ppm nickel.
The company says the results show significant nickel potential in its target areas. While the average background nickel value from the program is 130 parts per million, it shows the high of 1808ppm nickel, with the next four highest values coming in at 1607ppm, 1513ppm, 1479ppm and 1457ppm.
Most importantly, Askari has noted a strong chromium correlation with the high nickel values, with an average background chromium value of 214ppm. The top five nickel responses correlate with some of the highest respective chromium values of 1100ppm, 2349ppm (the highest of the program), 1339ppm, 1121ppm and 1225ppm.
Askari Metals vice-president of exploration and geology Johan Lambrechts said: "The Company is encouraged by the results of this soil geochemical campaign which has demonstrated the significant potential to explore for a major nickel sulphide deposit. The East Pilbara has become an exploration hotspot for nickel, copper, gold and lithium with several major discoveries made and deposits developed. Nickel demand is on the rise as the critical metal is increasingly needed for the advancement of the global energy transition. Callawa presents an exciting opportunity to supply this demand, through development of a multi-commodity project with a focus on nickel and copper."
The company's 100 per cent-owned 167-square-kilometre Callawa project comprises a single granted exploration licence within the north-eastern margin of the Pilbara Craton. Structurally, it appears to overlie part of a “ring structure” showing characteristics of a porphyry terrane, while previous sampling in the area indicates the potential for significant mineralisation.
Management says an earlier review of historic rock sampling results within its tenement revealed copper values ranging from 2.5 to 19 per cent and up to 1000ppm nickel with associated cobalt, chrome and copper.
The results prompted Askari to embark on an extensive, shallow, soil-auger drilling geochemical sampling campaign, comprising 864 holes regularly arrayed on a rectangular grid pattern that is well-suited to the local north-east/south-west strike of the regional geology as indicated from magnetics.
The company undertook a detailed data review of the full multi-element assay suite, in addition to critical element correlations and statistical analysis. It says studies to date indicate that while the nickeliferous mineralisation appears unlikely to be of the secondary, near-surface style typical of lateritic weathering, the strong geochemical correlations (above 90 per cent) between nickel, cobalt and chrome, and the high correlation (above 80 per cent) between nickel and magnesium, indicate that several characteristics of magmatic nickel sulphide mineralisation exist and warrant immediate follow-up investigation.
Intriguingly, the company says that the magnesium and chromium content and the typical nickel-copper ratio of the sample results indicate a high potential for peridotite-dunite-associated nickel mineralisation.
It adds that the most prospective zone for magmatic nickel sulphide mineralisation it identified from the geochemical analyses correlates closely with areas of anomalism in its previously-acquired high-resolution airborne magnetics data, as the elevated magnetics are consistent with iron-rich mafic and ultramafic associations that are typical of host rocks having potential for nickel sulphide and related mineralisation.
Askari says it plans to have its aeromagnetic data reviewed and interpreted by geophysical consultants to identify primary targets and that it will undertake a second follow-up soil auger program to infill the current drilling grid to better define the potentially mineralised targets. It appears to be a good call by the company before it commits to higher-cost exploration methods.
Its soil auger geochemistry appears to be generating good, coherent targets that are supported by structure as indicated by magnetic data and it is a relatively rapid and low-cost reconnaissance exploration method considering the terrain. It is also a potentially useful cross-check on previous results, so it will be important to ensure compatibility between the two programs by keeping sampling and analytical methods consistent throughout and avoiding any possibility of significant analytical batch differences.
The word “Askari” has historically meant “soldier” or “leader”. Now, it might be worth getting a good grandstand seat to watch from as the company soldiers ahead with its discovery with the possibility of it opening a new nickel-copper-cobalt project in an increasingly busy area.
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By Doug Bright
