A review of historical data relating to Castillo Copper’s (ASX: CCZ) Big One deposit and Boomerang mine in Queensland’s Mount Isa copper belt 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.
Also of interest was an 8m intercept at 2.33% copper from 44m, including 6m at 3% from 45m and 5m at 3.28% from 45m.
The intercepts demonstrated the Big One mineralisation to be at shallow depth and along a 600m strike zone.
Additionally, 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.
Castillo’s review has been labelled a “game changing development” for the Mount Oxide pillar, which sits in the heart of the Mount Isa copper belt and contains the Big One and Boomerang discoveries.
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 Mount Oxide pillar and creating incremental value for our shareholders.”
Castillo’s work coincides with a resurgence of interest in the region by blue-chip groups including Rio Tinto (ASX: RIO), Mount Isa Mines and Newmont Goldcorp applying for greater exploration footprints.
At morning trade, Castillo Copper’s shares were up 30.43% to $0.03.