A review of historical data relating to Castillo Copper's Big One deposit and Boomerang mine 200km north of Mount Isa has confirmed the presence of a supergene orebody, with potentially greater upside on definition of the size and scale of any underlying deposits.
Original logs and assay results obtained from a 1993 drilling campaign at Big One by previous owner West Australian Metals showed "excellent economic intercepts" grading up to 28.4% copper.
Among the results was a 3m intercept at 12.25% copper from 42m, including 2m at 17.87% from 43m and 1m at 28.4% from 44m.
The intercepts demonstrated the Big One mineralisation to be at shallow depth and along a 600m strike zone.
Historic production records for Boomerang verified that 4211.2 tonnes of oxide ore was mined from 1944 to 1974, grading approximately 6% copper, with output of 250.9t copper metal.
Castillo said the historic data is an "encouraging start", however fieldwork is imperative to determine the next steps in developing a staged exploration campaign for investigating Boomerang.
Managing director Simon Paull said the historical data results would be a "tremendous windfall" for the company's exploration efforts in the region.
"Our geology team now has ample data points to start formulating a drilling campaign to re-test and potentially expand the known ore body at these targets," he said.
"This would be a great start to developing the high-priority Mt Oxide pillar and creating incremental value for our shareholders."
Castillo aims to develop a copper mining operation at Mt Oxide, which is in an area that hosts a number of historical and operating copper mines.
Glencore, Rio Tinto and Newcrest also have prospects in the area.
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