American West Metals has confirmed the presence of a potentially lucrative new copper system at its Storm project in Canada after sifting through preliminary assay results from a recently plunged diamond hole. The discovery sits beneath the operation’s known near-surface mineralisation and has drawn comparisons to some of the world’s premier sedimentary-style copper deposits.
The Perth-based explorer says the discovery hole is linked to a suite of untested geophysical anomalies that stretch across a 5km-plus parcel of land about 1km west of a highly prospective zone termed “4100N”.
The breakthrough, coupled with the zone’s scale and lack of exploration, suggests the company could have a significant new copper system on its hands.
American West believes the find validates its geological model – a framework that theorises the project’s near-surface mineralisation stems from a deeper lying sedimentary copper source.
The discovery hole was drilled to a downhole depth of about 383m into a previously untested geophysical anomaly and intersected both a shallow and deeper sequence of visual copper and zinc mineralisation. The shallow zone included 34m of chalcocite over several intervals from 17m downhole.
The bore’s deeper counterpart housed a broad package of sulphide mineralisation including 68.8m of chalcopyrite, pyrite and sphalerite mineralisation – strong sources of copper metal – from 277m downhole.
First pass assay analyses have since confirmed the visual occurrences of chalcopyrite and sphalerite.
Management argues the area’s metal associations, zonation and geophysics mean the discovery hole could potentially have been plunged at the edge of a more robust mineral system, setting up a compelling case for subsequent work.
American West Metal’s Managing Director, Dave O’Neill:“These results demonstrate that – in addition to the near-surface high-grade copper deposits – we have a second type of copper deposit at Storm. This sedimentary copper mineralisation style is typically associated with very large deposits, such as the large-scale copper deposits in the Congo and the Kupferschiefer deposits in Central Europe.”
The company is also progressing activity further east at a highly prospective zone dubbed “2750N”.
Recent work at the site has confirmed the continuity of shallow, high-grade copper with several solid strikes, including a 57m interval grading 2.5 per cent copper from 8m with a richer 1m hit at 21.9 per cent copper from 14m downhole.
The company is now looking to develop a definitive flow sheet for a direct shipping ore, or DSO operation using ore from 2750N.
Material flagged as amenable to DSO can be dispatched directly to buyers after minor and economical processing, including a simple blend of crushing, screening, sorting and ore blending.
Previous processing on samples derived from American West’s wider Storm project yielded a DSO product with a grade of over 53 per cent copper using minimal processing methods.
Although it’s still early days, Storm continues to toss up a suite of shallow copper mineralisation across a range of prospects and is now adding a potentially lucrative new source of deeper lying copper into the mix.
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By Matt Birney
