Octava Minerals’ recent geochemical soil-sampling program has identified extensive nickel, copper and cobalt anomalism at the company’s 63-square-kilometre Yallalong project, about 220km north-east of the Western Australian regional city of Geraldton.
With maximum assay values from the program including 187 parts per million nickel, 279ppm copper and 130ppm cobalt, management believes the early signs show it may be a precursor to unearthing another significant nickel-copper-platinum group elements (PGE) discovery in the virgin and mostly unexplored West Yilgarn mineral province
Soil anomalies for the three metals appear to be at least partly coincident, generally elongated north/north-east between 1km and 3km east of and close to parallel with the Darling Fault. They correlate strongly with the trend of project-scale magnetic highs and extend between 6km and 10km. The company reports they may be up to 400m wide.
Nickel and copper anomalisms are both broadly contained within respective 25ppm and 50ppm contours that enclose more strongly-defined signatures in two main northern zones of more than 50ppm nickel and 75ppm copper. Cobalt anomalism is within a regional-scale 10ppm contour envelope, with values exceeding 25ppm confined within two well-defined northern zones that coincide with nickel and copper anomalies.
Each metal is also represented by a separate small, but distinct zone of coincident anomalism about 2km south of the most southern of the two main zones. The target area has only recently become recognised as prospective for nickel-copper-PGE mineralisation associated with mafic and ultramafic intrusions along the Darling Fault, which borders the western margin of the ancient granitic Yilgarn craton.
The West Yilgarn mineralisation is entirely unexplored and is considered one of the world’s most exciting new nickel sulphide provinces. It means Yallalong might be in good company, as it resembles the renowned Julimar project further to the south where Chalice Mining is systematically targeting greenfield high-grade nickel-copper-PGE discoveries.
Chalice’s exploration project is centred on a newly-recognised geological belt more than 30km long and known as the Julimar Complex, where the mafic-ultramafic intrusive belt is prospective for magmatic sulphide mineralisation. It has a rare geometry similar to other major mafic-ultramafic magmatic systems worldwide that host some of the world’s biggest deposits, including Norilsk-Talnakh and Jinchuan.
Octava’s geochemical soil-sampling program is a collaborative effort with the CSIRO through the latter’s “Kick-Start” exploration support scheme. The program is designed to optimise sample collection though statistical and machine learning models, all the way from the pre-survey stage through to the final stage of geochemical interpretation, using a single framework for integrating landscape context throughout the exploration process.
The company’s current phase of soil sampling is now complete and all assay results have been received. The CSIRO is completing interpretation work and management expects to receive the final report soon.
Program of Work (POW) clearances have been received and work is progressing towards gaining the heritage clearance needed to pave the way for drilling.
Octava’s fortunes could be significantly enhanced if it finds itself as an early mover with a fresh geochemical interpretation that points to a significant new nickel-copper-PGE discovery in a virgin province that is just 640km from Perth.
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By Doug Bright
