HomeMediaProject UpdatesNWQ COPPERAssays extend mineralisation; Next campaign to target northern conductor

Assays extend mineralisation; Next campaign to target northern conductor

  • Interpreting the full assay results holistically from the second drilling campaign (out of three planned), which was designed to extend known mineralisation and test the halo south of the dacite dyke, highlighted the following:
    • The first four drill-holes extended known mineralisation, as they were proximal to the dacite dyke, with the best intercepts comprising –

9m @ 1.42% Cu fm 88m incl: 4m @ 3.06% Cu fm 92m & 1m @9.19% Cu fm 92m (BO_317RC) (1)

5m @ 1.06% Cu fm 141m (BO_316RC) (1)

16m @ 0.59% Cu fm 166m incl: 3m @ 1.76% Cu fm 176m (BO_318RC)

3m @ 1.22% Cu fm 65m (BO_315RC) (1)

    • These intercepts are in-line with results from the first drilling campaign completed in late 2020 which comprised –

40m @ 1.64% Cu fm surface incl: 11m @ 4.40% Cu fm 24m, 5m @7.34% Cu fm 28m & 1m @ 16.65% Cu fm 29m (BO_303RC) (2)

44m @ 1.19% Cu fm surface incl: 14m @ 3.55% Cu fm 27m, 3m @ 10.88% Cu fm 37m & 1m @ 12.6% Cu fm 37m (BO_301RC) (2)

    • The drill-holes that targeted the halo, south of the dacite dyke, verified the known system runs for only circa 400m along the strike extent then intersects at a sharp angle with a major regional fault
  • The third drilling campaign, comprising at least 22 drill-holes, will target several prime areas including the sizeable bedrock conductor on the north side of the dacite dyke (2):
    • Significantly, the geophysical characteristics of the northern bedrock conductor are identical to the known system prevalent along the line of lode (3)
  • In addition, across the Big One Deposit are 12 separate legacy stockpiles from mid-1990 mining operations, which were assessed to comprise – 7,407t @ 1.17% Cu, while assayed rockchip samples returned up to 3.32% Cu (Appendix A)
  • At the Arya Prospect, the logistics team are on site, preparing the helipad / drill-pads in readiness for the equipment to arrive
  • Further, due diligence is progressing on the Litchfield & Picasso Lithium Projects **

Castillo Copper’s Managing Director Simon Paull commented: “With results in from the second drilling campaign, it’s encouraging that highgrade mineralisation was extended. Moving forward, the third drilling campaign at Big One Deposit will hit priority targets north of the line of lode, which includes a sizeable bedrock conductor. In the interim, however, the Board is looking forward to work finally commencing at the Arya Prospect and results of the due diligence programme which is continuing on the Litchfield & Picasso Lithium Projects.”

Castillo Copper Limited (“CCZ”) is pleased to report that the full assay results for the second campaign at the Big One Deposit have been returned, delivering findings consistent with the geology team’s expectations. The campaign comprised 20 reverse circulation drill-holes for a total of 2,632m and one with a HQ diameter diamond-cored tail for a total of 32m (BO_334DD). Refer to Appendix A for full details of the drilling and sampling programs.

SECOND CAMPAIGN REVIEW

Interpreting the assays results from the second drilling campaign holistically has significantly aided the geology team’s understanding of the underlying system. The first four drill-holes (BO_315-318RC), which were designed to extend known mineralisation, clearly met this objective.

The best intercepts include the following:

9m @ 1.42% Cu fm 88m incl: 4m @ 3.06% Cu fm 92m & 1m @ 9.19% Cu fm 92m (BO_317RC) (1)

5m @ 1.06% Cu fm 141m (BO_316RC) (1)

16m @ 0.59% Cu fm 166m incl: 3m @ 1.76% Cu fm 176m (BO_318RC)

3m @ 1.22% Cu fm 65m (BO_315RC) (1)

These intercepts are broadly in line with results achieved from the inaugural drilling campaign undertaken in late 2020, which comprised:

40m @ Cu 1.64% fm surface incl: 11m @ 4.40% Cu fm 24m, 5m @ 7.34% Cu fm 28m & 1m @ 16.65% Cu fm 29m (BO_303RC) (2)

44m @ 1.19% Cu fm surface incl: 14m @ 3.55% Cu fm 27m, 3m @ 10.88% Cu fm 37m & 1m @ 12.6% Cu fm 37m (BO_301RC) (2)

Moreover, as shown in Figure 1 below, the drill-holes are mostly proximal to the open pits which were mined during the mid-to-late 1990s (2).

FIGURE 1: BIG ONE DEPOSIT – DRILL-HOLES ALONG THE LINE OF LODE

The HQ diamond core hole, BO_334DD, which intersected the dacite dyke, missed its primary target, as the assays returned 1m @ 0.52% Cu from 86.4m (BO_334DD) – refer to Appendix A. During the next drilling campaign, the targeting will be altered to increase the probability of intersecting mineralisation.

Halo zone

The drill-holes which tested the halo to the south of the dacite dyke largely confirmed the system runs for only circa 400m along the line of lode. At a certain juncture toward the eastern end it intersects, at a sharp angle, with a major regional fault. Consequently, the mineralisation in this region extends beyond the confines of the 6m-wide dacite dyke into a mix of fractured quartzites and siltstones.

The best intercepts from the halo zone to the south and west of that intersection are as follows:

4m @ 0.56% Cu fm 100m incl: 1m @ 1.58% Cu fm 100m (BO_326RC)

5m @ 0.77% Cu fm 93m incl: 2m @ 1.57% (BO_327RC)

Third drilling campaign

Reflecting the fact there is still considerable exploration potential apparent at the Big One Deposit, a third drilling campaign, comprising at least 22 drill-holes has been formulated. This will target several areas on the northern side of the dacite dyke, including the sizeable bedrock conductor identified during the induced polarisation campaign (2).

It is important to note, the geophysical characteristics of the northern bedrock conductor are identical to the anomaly along the line of lode where known mineralisation has been discovered.

HIGH GRADE STOCKPILES

As part of the exploration program across the Big One Deposit, sampling occurred at 12 separate legacy stockpiles from mid-1990 mining operations (Figure 2). Accurate volumes were calculated from a drone survey, which assessed the stockpiles to comprise 7,407t @ 1.17% Cu. Based on sample rock-chips taken from the stockpiles, the assays returned up to 3.32% Cu reconfirming the high-grade nature of the underlying system. However, there will need to be further metallurgical testing and a mining lease secured to process the stockpiles.

FIGURE 2: STOCKPILES AT BIG ONE DEPOSIT

TRACK RECORD

Factoring in two historical drilling campaigns, coupled with CCZ’s 2020-21 programs, the table below highlights the best intercepts recorded at the Big One Deposit (2). The major takeaways from the work completed to date highlight an underlying copper system that is relatively shallow. However, the full picture will not be apparent until the northern bedrock conductor is test-drilled, and some deeper drill-holes test the eastern and downdip extents of the deposit.

FIGURE 3A: BEST INTERCEPTS – FINAL ASSAYS FOR 200/300 SERIES (2)

303RC: 40m @ 1.64% Cu fm surface incl: 11m @ 4.40% Cu fm 24m, 5m @ 7.34% Cu fm 28m & 1m @ 16.65% Cu fm 29m

301RC: 44m @ 1.19% Cu fm surface incl: 14m @ 3.55% Cu fm 27m, 3m @ 10.88% Cu fm 37m & 1m @ 12.6% Cu fm 37m

318RC: 16m @ 0.59% Cu fm 166m incl: 3m @ 1.76% Cu fm 176m

213RC: 12m @ 0.79% Cu fm 52m incl: 8m @ 1.06% Cu fm 57m, 3m @ 2.03% Cu fm 58m, 1m @ 4.27% Cu fm 59m & 1m @ 1.46% Cu fm 62m

317RC: 9m @ 1.42% Cu fm 88m incl: 4m @ 3.06% Cu fm 92m & 1m @ 9.19% Cu fm 92m

207RC: 8m @ 0.47% Cu fm 84m incl: 2m @ 1.10% Cu fm 85m & 1m @ 1.49% Cu fm 86m

306RC: 8m @ 0.41% Cu fm 16m and 4m @ 0.97% Cu fm 96m incl: 2m @ 1.30% Cu fm 96m

206RC: 8m @ 0.42% Cu fm 54m incl: 3m @ 1.02% Cu fm 59m & 1m @ 1.75% Cu fm 60m

316RC: 5m @ 1.06% Cu fm 141m

302RC: 5m @ 0.66% Cu fm 35m incl: 1m @ 1.30% Cu fm 37m

305RC: 5m @ 0.53% Cu fm 34m incl: 1m @ 1.19% Cu fm 38m

FIGURE 3B: HIGH-GRADE HISTORIC INTERCEPTS (2)

BO017: 34m @ 1.51% Cu from surface incl: 21m @ 2.25% Cu fm surface, 12m @ 3.44% Cu fm 3m, 6m @ 4.79% Cu fm 3m and 1m @ 9.4% Cu fm 9m

B07: 3m @ 12.25% Cu from 42m incl: 2m @ 17.87% Cu from 43m; and 1m @ 28.4% Cu from 44m

B05: 8m @ 2.33% Cu from 44m incl: 6m @ 3.00% Cu from 45m; and 5m @ 3.28% Cu from 45m

B06: 4m @ 2.20% Cu from 44m incl: 2m @ 3.19% Cu from 46m and 1m @ 3.63% Cu from 47m

B25: 6m @ 1.55% Cu from 66m incl: 5m @ 1.79% Cu from 66m and 2m @ 2.08% Cu from 66m

B02: 4m @ 1.45% Cu from 36m incl: 1m @ 2.48% Cu from 37m

B26: 3m @ 1.36% Cu from 73m incl: 2m @ 2.29% Cu from 73m and 1m @ 1.02% Cu from 74m

BO015: 18m @ 0.86% Cu fm 11m incl: 6m @ 1.85% Cu fm 20m, 3m @ 2.98% Cu fm 20m and 1m @ 8% fm 20m

B07: 9m @ 0.84% Cu from 32m incl: 3m @ 1.69% Cu from 36m; and 1m @ 2.37% Cu from 36m

B08: 3m @ 0.80% Cu from 48m incl: 1m @ 1.18% Cu from 49m

Source: CCZ geology team

Next steps

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

  • Commencement of drilling at the Arya Prospect.

For the lithium projects, the initial focus will be on the following areas:

  • Continuation of due diligence on the Litchfield and Picasso Lithium Projects.

There are several ongoing steps for the Zambia operations, including:

  • Complete the IP survey at the Luanshya & Mkushi Projects then analyse the results for incremental targets for test-drilling; and
  • Commence work on the inaugural drilling campaign for the Luanshya Project.
References
  1. CCZ ASX Release – 26 July 2021
  2. CCZ ASX Release – 14 January 2020, 11 January 2021 & 10 February 2021
  3. CCZ ASX Release – 20 May 2021