Castillo Copper announces potential base metal and graphite mineralisation at Arya Prospect

Castillo Copper’s Managing Director, Simon Paull, commented: “The preliminary findings from the drilling campaign are quite remarkable, as over 200 m of carbonaceous siltstone and schist, exhibiting occurrences of base metal sulphides and fine-grained graphite mineralisation, was intersected. This is an exciting development, particularly given strong prevailing demand for battery related minerals such as copper, cobalt, and graphite. The Board looks forward to reviewing the assay results and remains committed to continued drilling at the Arya Prospect.”

Highlights

• So far, three drill-holes have been completed from two drill pads, with standout, AR_002RC, reaching a depth of 238 m:
  • Approximately 200 m of dark grey and black carbonaceous siltstone/schist was intersected, with occurrences of scattered base-metal sulfides and fine-grained graphite mineralisation, remaining open at depth.
  • Encouragingly, visible but scattered chalcopyrite (copper sulfide mineralisation) was observed in drill-hole AR_001RC.
• All samples have been dispatched to the laboratory for comprehensive analysis including base (copper, zinc)/speciality metals (cobalt, REEs) and total graphitic carbon.
• Subject to weather, drilling will continue through to the end of November 2021, resuming in 2022, as there are now new targets to drill-test to determine the full extent of the underlying systems:
  • The next phase of drilling will complete testing the known electromagnetic anomalies EG01, EG02 and EG10.
  • Further, the geology team plan to drill test the significant magnetic anomaly to the south of EG01, EG02 and EG10 as this may be a primary source of base metal mineralisation.
• A comprehensive update will be released once the assays are returned and the geology team interprets all pertinent fundamentals.

Mineralisation intersected

Of the three drill-holes completed from two drill-pads at the Arya Prospect, all intersected thick horizons of black carbonaceous siltstone/schist, between 30 – 40 m from surface. Notably, approximately 200 m of dark-grey/black carbonaceous siltstone/schist was intersected in AR_002RC, with coincident base metal (portable XRF readings) and graphite mineralisation occurrences recorded. Encouragingly, scattered, but visible chalcopyrite (copper sulfide mineralisation) was observed in AR_001RC. Note, the visible sulphides are estimated to range between 1 – 3% by volume, but estimations of graphite content are not possible by portable XRF, and visible estimation was difficult due to the amount of black schist (estimated 1 – 5%).

All samples have been sent to the laboratory for further analysis, with a specific request to test for all base/speciality metals, total carbon, sulfur, and total graphitic carbon.

Drilling campaign

The drilling campaign will run through until the end of November 2021, resuming in 2022.

Once the assays are returned, the geology team will conduct a full review and chart the next targets to focus on, so as to fully understand the underlying systems. Notably, the next phase of drilling will complete testing of the known electromagnetic anomalies: EG01, EG02 and EG10.

In addition, the team intend to drill-test the sizeable magnetic anomaly that is proximal (south) to EG01, EG02 and EG10 as this potentially could be the primary source of base metal mineralisation.

Surface mapping and rockchip sampling

Concurrently, the geology team has undertaken a circa 200 x 200 m mapping/rock chip sampling campaign at the Arya Prospect, which is designed to extend the known surface anomaly to the south.

Further, rock specimens were collected from fourteen locations across the Eldorado Prospect – further to the south-east. The terrain is rougher, steeper, and more timbered than the Arya Prospect. Interestingly, the surface geology is more varied, with signs of copper mineralisation apparent.

Rock specimens collected from the Arya and Eldorado Prospects have been analysed with the portable XRF gun and magnetic susceptibility tool. The samples will be forward to the laboratory for assaying, but the field results from both tools suggest the Eldorado Prospect is prospective for copper mineralisation.

Next steps

In Queensland, the following is set to take place over the coming weeks:

• Assay results and forward drilling plans for the Arya Prospect.

For the lithium projects:

• Ongoing due diligence for the Picasso and Litchfield Lithium Projects, including return of assay results for surface sampling campaigns.
• There are two ongoing steps for the Zambia operations, including:
  • Complete the IP survey at the Mkushi Project.
  • Complete work on the inaugural drilling campaign for the Luanshya Project.