Castillo Copper Ltd (ASX:CCZ) (LON:CCZ) (FRA:7OR) is buoyed by preliminary interpretations by a geophysicist consultant that reveal possible extensions to mineralisation at Big One Deposit within the Mt Oxide Project in northwest Queensland’s Mt Isa Copperbelt.

After completing the inaugural induced polarisation (IP) survey, the consultant found compelling evidence that highlights incremental mineralisation within fault structures outside the trachyte dyke.

This finding has the potential to extend known mineralisation as initially it was believed to be constrained within the trachyte dyke.

It also increases the potential structural targets across the Big One Deposit.

“Enhance exploration potential”

Castillo Copper’s managing director Simon Paull said: “Overall, the geophysics campaign has successfully identified a possible extension to known mineralisation beyond the line of lode at the high-grade Big One Deposit.

“More importantly, however, it has delivered several new high priority structural targets for the next phase of drill-testing that enhance the overall exploration potential.”

Shares have jumped 4.65% in early trading to A$0.045.

IP survey of six lines

The IP survey comprised six lines, ranging from 500-700 metres long, and spaced nominally 200 metres apart over the 1,200-metre line of lode which has been subject to three drilling campaigns over the past five decades.

This campaign’s primary objective was to identify massive new sulphide bedrock conductors along the strike extent and extend known mineralisation.

The geology team also wanted geophysical insights into several known yet under-explored nearby anomalies that included previously mapped gossanous outcrops to the northeast of the 2020 drilling campaign and scattered historical surface stream sediment and rock chip sampling.

In reviewing the results from the IP survey, it was found that Line 3 delivered the most compelling new insights.

Target materially larger

A large untested bedrock conductor was identified around 200 metres north of the line of lode where last year’s high-grade discovery was located.

This target is materially larger than the anomaly intersected in 2020 which produced the following nearby intercepts between Lines 2 and 3:

  • 303RC: 40 metres at 1.64% copper from surface including 11 metres at 4.4% from 24 metres, 5 metres at 7.34% from 28 metres and 1-metre at 16.65% from 29 metres; and
  • 301RC: 44 metres at 1.19% copper from surface including 14 metres at 3.55% from 27 metres, 3 metres at 10.88% from 37 metres and 1-metre at 12.6% from 37 metres.

In addition, south of the line of lode along Line 3, are three more untested anomalies that build on the Big One Deposit’s exploration potential.

Enhanced understanding

One of the key value-add insights was reconciling the geophysics findings with all legacy drilling results, as this enhanced the geology team’s understanding of the underlying system.

The next phase of the drilling campaign, which is due to commence shortly, is being realigned to intersect newly identified targets and bolster the chances of achieving optimal results.

Next steps

There are several concurrent next steps CCZ’s teams are working on:

  • The geophysicist consultant will prepare a 3D model of the IP survey findings from the Big One Deposit; and
  • An upcoming drilling campaign will soon be finalised ahead of the team moving to site to commence work.