Miramar Resources Ltd (ASX:M2R) says an ongoing review of historical data from the company’s 100%-owned Bangemall Projects, in the Gascoyne region of WA, has helped it pick out several new targets, including a diamondiferous lamproite at the Blue Bar prospect.
The company is also keen to explore a 100-kilometre-long uranium anomaly across multiple Bangemall tenements and outcropping nickel-copper-cobalt mineralisation associated with Mundine Well dolerite.
Miramar executive chairman Allan Kelly said the identification of multiple new targets underscored the highly prospective but underexplored nature of the company’s strategic 2,000-square-kilometre Bangemall landholding.
“Proterozoic mobile belts can host many different deposit types, including diamonds,” he said.
“The Capricorn Orogen is vastly underexplored compared to other mobile belts within Australia and, as a result, we continue to identify numerous highly prospective targets which we look forward to progressing once the relevant tenements are granted.”
Blue Bar diamond potential
The company’s ongoing review of historical data for the Blue Bar prospect has uncovered a report identifying a cluster of lamproites, including one which reportedly contained 27 microdiamonds.
The historical report described the diamondiferous lamproite as 365 metres across, “intruding through dolerite and dolomite” and consisting mostly of “fine-grained olivine lamproite with large xenoliths of mantle-derived material”.
The report indicates that several 40-kilogram samples were processed via wet sieving and concentrated, using both gravity and heavy liquids, before microscopic examination of the heavy mineral concentrate.
The process apparently extracted multiple diamond indicator minerals, including various garnets, picro-ilmenite and chrome diopside, along with the 27 microdiamonds, while gold and platinoid grains were also recovered, from samples related to the adjacent dolerite sill.
Minimal information about the sampling locations was included in the report, but sketch maps showed the locations of the diatremes in relation to topographic features.
Magnetic data appears to highlight the diamondiferous lamproite and, potentially, another unmapped diatreme.
No further work was completed on the tenement, which was subsequently surrendered in 1998.
Miramar is keen to conduct a reconnaissance field trip to confirm the location of the reported diatremes and conduct check sampling of the diamondiferous diatreme and the additional circular magnetic anomaly.
Nickel-copper-cobalt mineralisation
The company has previously reported that historical data had revealed strongly anomalous nickel and copper results from rock chips, stream sediments and soil samples within the Blue Bar prospect, including a cluster of rock chip samples apparently associated with a younger dolerite dyke of the Mundine Well suite.
One rock chip sample, CAPR0428, returned 0.3% nickel, 0.1% copper and 0.8% cobalt, of a similar tenor to outcropping nickel-copper-PGE mineralisation discovered by Dreadnought Resources within the 'Money Intrusion', also interpreted to be part of the Mundine Well suite.
Once the relevant tenements are granted, the company intends to conduct mapping, sampling and/or geophysics over this high-priority nickel-copper-PGE target.
Regional uranium anomalism
A review of regional radiometric data has revealed a very large and high amplitude uranium anomaly that stretches over at least 100 kilometres of strike within several of Miramar’s tenement applications.
The regional-scale uranium anomaly is towards the northern edge of the Edmund Basin, at the contact with the older Ashburton Basin rocks, and apparently associated with the Jillawarra formation sediments where they have been intruded by later dolerite sills of the Kulkatharra suite.