Cooper’s Attina prospect returns ‘highest gold grade to date’

Recent rock chip sampling at Cooper Metals’ (ASX:CPM) Attina copper-gold prospect has returned the highest gold grade to date of 500-plus rock chips collected over the past three years.

Sample MER386 at the Attina prospect within the Mt Isa East Project assayed 52.8g/t Au with 12.35% Cu, taken from a quartz-rich gossanous float material. Some 23 rock chips have been taken to date at Attina, most of which have more than 1% Cu and three samples more than 1g/t Au, the company says.

Cooper has been focused on the Attina and Solo copper-gold prospects that have been identified through mapping and geochemical sampling of prospective areas in the company’s Ardmore tenement within the Mt Isa East Cu-Au Project.

In 2023 Cooper engaged independent consultants to review the Ardmore tenement copper-gold prospectivity, which has highlighted eleven high priority areas for follow-up exploration.

An independent review of available geophysics and geochemical data highlighted 11 targets primarily of high magnetic response, associated with significant structures and lithological contacts for further exploration.

The company says some of these areas have had initial rock chip and soil sampling, including Attina and Solo Prospects. Continued sampling and mapping at these prospects is in progress to better delineate the copper-gold potential of these targets for drill testing.

Cooper Metals Managing Director Ian Warland says the two new prospects are showing highly encouraging copper-gold anomalism in soils and rock chips located in favourable structural positions.

“The areas were followed up as part of an external prospectivity review of the Ardmore tenement in 2023, which helped identify eleven targets from a desktop review of detailed aeromagnetic data, geological mapping and satellite imagery,” Warland says.

“Attina looks especially interesting, due to the high gold grades and the interpretation of a complex trap site formed potentially in a zone of low pressure, which resulted in increased shearing around the contact between a rigid granite body within the Corella Formation.

“We are continuing to improve the geochemical coverage and mapping to assess these areas for future drill testing and look forward to updating the market with our progress.”

The Attina prospect was identified as a target during an independent desktop prospectivity review over tenement EPM19125 in 2023. Attina is located 5.5km northeast of Carnaby’s (ASX:CNB) Mt Hope deposit and comprises sub crop of a discontinuous line of gossanous quartz veins varying from 1m to 15m wide, which has been traced for up to 700m.

The copper-gold anomalism is hosted in Corella metasediments deforming around the Overlander Granite, with mafic intrusions in the localised arcuate major structure. Cooper interprets this as a possible low lithospheric pressure shadow providing a favourable zone of shearing for mineralising fluids migrating from major structures in the area and forming a potential trap site for copper-gold mineralisation.

The Solo prospect was also identified during the independent desktop prospectivity review, as a discrete magnetic high on a north-south structure, coincident with the contact between the Overlander Granite and Corella Formation.

Initial pXRF soil sampling has delineated two copper anomalies some 300m long each. The stronger of the two is the eastern anomaly coincident with the main granite Corella contact zone and extends for about 300m > 500ppm (pXRF) Cu in soil.

Only one rock chip has been taken from the site with others pending assay. Cooper reports rock chip MER538 returned 0.42% Cu with visible sulphides. Further sampling is required to ascertain the source of the copper anomalism at Solo and extension of the soil grid.

Write to Adam Orlando at Mining.com.au

Images: Cooper Metals
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Written By Adam Orlando
Mining.com.au Editor-in-Chief Adam Orlando has more than 20 years’ experience in the media having held senior roles at various publications, including as Asia-Pacific Sector Head (Mining) at global newswire Acuris (formerly Mergermarket). Orlando has worked in newsrooms around the world including Hong Kong, Singapore, London, and Sydney.