Castillo Copper Ltd (ASX:CCZ) has identified another large mineralised system with iron oxide-copper-gold (IOCG) targets at the Mt Oxide pillar in northwest Queensland, enhancing the project's exploration upside and potential scale.
Detailed work on IOCG target Flapjack has interpreted it to be part of a larger mineralised system that comprises the Crescent (IOCG) and Johnnies (shear-hosted copper/supergene ore) prospects.
A closer review of Flapjack verifies that it is within a zone of structurally controlled east-northeast trending haematitic-quartz veins.
“Surprised” by upside
Managing director Simon Paull said: “As we wind up the current geological review on the eight prospects across the Mt Oxide pillar, we continue to be surprised to the upside by the findings.
“Having a large relatively under-explored mineralised system, comprising three prospects that are known IOCG and shear-hosted copper targets, still leaves plenty of work ahead to extend these areas materially.
“Our teams are now working at a rapid pace to secure the necessary approvals to commence drilling at the Arya prospect and Big One Deposit.”
Shares have been up almost 17% in early trade to 2.1 cents.
Additional work to determine extent
Based on interpretations by the company’s independent geology consultant, through analysing historic geophysics and geochemical data, the Flapjack and Crescent prospects are on the same fault system.
Castillo believes this is a ‘significant’ finding as the Flapjack and Crescent prospects are both IOCG targets.
Further work will be required to determine the extent and scale of prospective IOCG mineralisation, allowing test-drill targets to be formulated.
Further targets provided
There is anecdotal evidence all three prospects are sub-components of a larger mineralised system, especially factoring in that Johnnies proximity to the fault line and it being a shear-hosted copper-supergene ore target.
This enhances Mt Oxide pillar’s exploration and IOCG potential by providing further targets to investigate along the prospective mineralised trend.
High-grade surface assay results
High-grade surface assay results for coincident gold-copper occurrences also highlight key evidence supportive for IOCG mineralisation including:
- Stream sediment: up to 820ppb gold, 50ppm copper, 57ppm lead and 374ppm zinc;
- Soil: up to 81ppb gold, 292ppm copper, 212ppm lead and 803ppm zinc; and
- Rock chip: up to 1.37ppm gold, 606ppm copper, 981ppm lead and 463ppm zinc.
Castillo says a follow-up field trip is necessary to conduct incremental soil sampling above PC13, which is on the southern edge of the trendline that is interpreted to connect the Flapjack and Crescent prospects to reconcile its suitability as a future primary drill target.
Mt Oxide is one of three pillars Castillo is pursuing in its aim to become a mid-tier copper producer with the company also progressing a dual listing on the Standard Board of the London Stock Exchange.