Feb 10, 2021

Big One boost from ’70s data windfall

Big One boost from ’70s data windfall

A ‘windfall’ discovery of results from a 1970s drilling campaign has shed more light on Castillo Copper’s Big One deposit, backing its credentials as a high-grade copper system.

Geology consultants ROM Resources have uncovered comprehensive historical assays from a drilling campaign undertaken by Forsayth Minerals Exploration.

Castillo says that combining these findings with final assay results from its own 2020 campaign clearly extends known mineralisation at Big One deposit.

“All systems are go as we accelerate developing Big One deposit, especially aiming to extend known mineralisation further and identify new test-drill targets,” managing director Simon Paull said.

“Our two new initiatives are now taking shape, with an upcoming IP survey being planned and JORC modelling now underway.

“Discovering FME’s assays was a windfall, as we can now optimistically assert that Big One deposit is a high-grade copper system.”

ROM Resources have been appointed to model a JORC-compliant inferred resource for Big One, which lies within Castillo’s Mount Oxide project in North-West Queensland.

The Forsayth Minerals Exploration drill-holes are regarded as historical exploration results.

While they can support Castillo’s knowledge of the deposit, they cannot form the basis alone of any resource estimate.

The intercepts in the 22-hole campaign included 34m at 1.51 per cent copper, including 1m grading at 9.4 per cent copper.

A key positive is that the area covered by that work does not overlap with that tested in Castillo’s drill programs.

Castillo said it provided clear evidence the high-grade zone at Big One was constrained within the dyke, dipped more vertically than initial expectations and had the potential to scale.

  • The table below summarises the best comparable economic intercepts from drilling campaigns at Big One. It includes those carried out by Castillo Copper and former tenement holders West Australian Metals and Forsayth Minerals Exploration.

GeoDiscovery Group has been tasked with undertaking an extensive geophysical survey at Big One with two core goals:

* Potentially extend known mineralisation through identifying massive sulphide bedrock conductors along the 1200m strike extent at Big One; and

* Deliver fresh geophysical insights into several known yet under-explored nearby anomalies.