Caspin Resources Ltd (ASX:CPN) is preparing to begin a maiden diamond drilling program at the Yarawindah Brook Nickel-Copper-PGE Project north of Perth in Western Australia in mid-April.
The program of around 1,000 metres will target the priority XC-29 anomaly while a recently recognised platinum group elements (PGE) target at Yarabrook Hill prospect will also be drilled to test beneath a 2-kilometre strike of PGE surface mineralisation.
In December 2020, Caspin identified the highly prospective XC-29 anomaly, which consists of three discrete zones over a strike of 1.3 kilometres.
The anomaly is coincident with interpreted mafic and ultramafic rocks which are typical host rocks for orthomagmatic nickel-copper-PGE mineralisation.
Strong bedrock conductors
Since the initial identification by airborne EM, surface geophysical surveying has confirmed the presence of several strong (up to 2,500 siemens) bedrock conductors.
XC-29 anomaly has been modelled as four conductive plates, with likely faulted offsets and potentially folded.
The top of the conductors lies approximately 60-80 metres below surface and below the base of weathering as interpreted from the AEM survey.
This initial drilling program will target each of these plates with further drilling contingent on results.
Caspin’s airborne EM survey indicates that the anomaly extends further north, which will be surveyed during a second phase of FLTEM later in the year and subject to results from the current program.
Successful results from XC-29 would provide further encouragement to explore these anomalies.
New PGE target at Yarabrook Hill
A review of historical exploration has identified an opportunity to discover sulphide PGE (primarily palladium and platinum) mineralisation at Yarabrook Hill, beneath oxide mineralisation striking over 2 kilometres at surface.
Past exploration drill intersections include 29 metres at 1.03 g/t palladium and 0.35 g/t platinum from 5 metres and 7 metres at 1.24 g/t and 0.60 g/t from 10 metres.
Several drill programs have identified supergene mineralisation at shallow depths but rarely explored deeper than the weathered zone, nominally below 50 metres vertical depth.
Review of PGE exploration strategy
Caspin’s exploration focus to date at the Yarawindah project has been to identify high-value nickel, copper and PGE mineralisation hosted by massive sulphide deposits.
In this context, the company has successfully employed electromagnetic techniques and developed several new targets with XC-29 an immediate priority.
Caspin has also recently considered the potential for low-sulphide style, PGE-rich mineralisation, as reported by Chalice Mining at their Julimar Project, 40 kilometres south of Yarawindah Brook.
Importantly, this style of mineralisation typically occurs as minor disseminated sulphide, which is unlikely to be detected with electromagnetic techniques.
A small number of deeper drilling campaigns at Yarabrook Hill were focused on nickel and copper sulphide mineralisation but were rarely assayed for PGEs despite these elements all commonly occurring together.
The company is planning to drill two holes beneath stronger zones of oxide mineralisation that may overlie a higher-grade sulphide source, as palladium is relatively immobile in the weathering zone.
All approvals are in place to drill at Yarabrook Hill and XC-29.