Castillo Copper Limited (ASX: CCZ) has identified a large mineralised system at the company’s Mt Oxide project which covers the Flapjack, Crescent and Johnnies prospects.
Managing Director, Simon Paull, said a new, closer review of the Flapjack prospect has verified it is within a zone of structurally controlled ENE trending haematitic-quartz veins.
More significantly, based on interpretations by CCZ’s independent geology consultant (through analysing historic geophysics and geochemical data), the Flapjack and Crescent prospects, which are circa 6km apart, are on the same fault system.
Mr Paull said this is a significant finding as the Flapjack and Crescent prospects are both prospective IOCG targets.
Further work, specifically targeting the trajectory of this fault, will be required to determine the extent and scale of prospective IOCG mineralisation, allowing test-drill targets to be formulated.
Incrementally, factoring in Johnnies, a shear-hosted copper / supergene ore target, proximity to the fault line, there is anecdotal evidence all three prospects are sub-components of a larger mineralised system.
Mr Paull said that holistically, this significantly enhances Mt Oxide pillar’s exploration upside, especially IOCG potential, through providing further targets to investigate along the prospective mineralised trend.
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,” Mr Paull said.
“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.”
For the Flapjack prospect specifically, historic geology reports confirm the presence of haematitic-quartz veins laced with gold and a distinct chlorite alteration which is an indicator for prospective IOCG mineralisation.
More specifically, high-grade surface assay results for coincident gold-copper occurrences highlight key evidence supportive for IOCG mineralisation including:
Stream sediment: up to 820ppb Au, 50ppm Cu, 57ppm Pb & 374ppm Zn3;
Soil: up to 81ppb Au, 292ppm Cu, 212ppm Pb & 803ppm Zn3; and
Rock chip: up to 1.37ppm Au, 606ppm Cu, 981ppm Pb & 463ppm Zn3.
In 1992, a previous historic tenure holder conducted an aeromagnetic GEOTEM survey which identified a sub-surface magnetic anomaly circa 250m by 150m. Notably, the anomaly – called PC13 – is 600m south- west of the main soil grid within the Flapjack prospect.
Mr Paull said 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.
Castillo’s geology team is now working towards securing necessary approvals to commence drilling operations at targets within the Arya prospect and Big One Deposit.