Heritage reports and data within Queensland Government mining & resources records verified the existence of the prospects - Big One and Boomerang – within the 737 square kilometre project in the Mt Isa copper belt.
As well as complementing the AEM anomaly at Arya prospect, these prospects look to deliver incremental exploration upside for Mt Oxide, one of three pillars of Castillo’s strategy to become a mid-tier copper miner.
The company’s managing director Simon Paull said, “Our decision to undertake a forensic geological review on the Mt Oxide pillar has delivered an excellent outcome that significantly enhances CCZ’s overall exploration upside.
“Moreover, these left-field prospects potentially speed up our development timeline evolving CCZ into a mid-tier copper group.
“However, the immediate priority is to fast-track sending the geology team to site to assess the potential of these prospects then formulate a drill program to test the priority targets.”
Three Mt Oxide targets
Along with Arya, which is interpreted as a massive sulphide exploration target discovered by an aero-electromagnetic (AEM) survey conducted by Geoscience Australia, the company now has three high-priority targets to explore.
As part of the due process for Castillo’s upcoming dual listing on the London Stock Exchange, the geology team undertook a forensic review of heritage data relevant to the Mt Oxide pillar.
During this process the team uncovered historical reports completed by previous explorers.
Priority exploration targets at Mt Oxide.
Boomerang is in the southern central part of the Mt Oxide project in an area that Dampier Mining explored in 1975, locating sedimentary type copper mineralisation.
At the time, exploration comprised prospecting, geological mapping and rock sampling followed by RAB drilling nine holes to test the mineralisation.
Boomerang prospect consists of copper mineralisation in one horizon, while the surface expression is 800 metres along strike of continuous secondary copper-stained quartz sandstone.
Big One is in the northern central part of Mt Oxide with previous exploration conducted by Carpentaria Exploration (1981), MIM Exploration (1992) and Savannah Resources (2007).
Earlier exploration included stream sediment surveys, soil sampling and a 21-hole reverse circulation drilling campaign in 1993.
In summary, this prospect is potentially a sedimentary copper deposit over a 600-metre strike length.
CCZ’s London-based director Ged Hall said: “Our geology team has delivered an exciting left-field result that has boosted the potential scale of our Mt Oxide pillar.
“This is clearly very encouraging news that our UK investors will welcome wholeheartedly.”
Program to be redesigned
Castillo Copper intends to redesign the current Mt Oxide exploration program to incorporate the new prospects.
The priority now is to expedite sending a geology team to the site to reconcile legacy data with field observations across the three exploration targets.
This work is aimed at facilitating the formulation of an inaugural drill test campaign.
Forensic geological work will also continue to review and evaluate any additional historical reports to broaden understanding of the underlying geology from previous exploration and identify new targets.