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Large Copper - Antimony System at Bulla Park
Highlights
- Previous diamond drilling shows broad intervals of disseminated copper - antimony mineralisation
- Previous intercepts have contained significant sulphidic copper and antimony mineralisation, such as:
- 89m at 0.30% Cu and 0.10% Sb, including 33m at 0.47% Cu and 0.15% Sb (19CA002, 176m to 265m)
- Copper grades up to 1.46% Cu (19CA002, 246m to 247m)*
- Antimony grades up to 0.5% Sb (19CA002, 246m to 247m)*
- Copper and antimony grades increase towards a broad zone of faulting targeted by recently drilled diamond hole BPD09 (assays awaited)
Mineralisation is dominantly tetrahedrite (copper - antimony sulphide) and minor chalcopyrite and stibnite (antimony sulphide). Antimony grades in previously assayed drill hole intercepts are approximately 30% to 35% of the copper grade, reflecting the theoretical composition of tetrahedrite (Cu12Sb4S13).
Recently drilled BPD09 (see ASX release of 13 August 2024) was designed to test an interpreted fault zone where higher copper – antimony grades were anticipated. The hole successfully intersected a broad zone from 120m to 338m (218m) of faulting, fracturing, disseminated copper- antimony sulphides, siderite alteration, veining and stockworks, and tectonic and hydrothermal breccias. The core samples from BPD09 are currently in a laboratory undergoing preparation. Assay results are expected to be received during September.
* See Appendix 1 for complete Cu and Sb assays for drill hole 19CA002
Antimony grades at Bulla Park follow the copper distribution. High grades of copper are found with better antimony grades. Apart from the dominant antimony mineral tetrahedrite, stibnite occurs as radiating needles in fractures and makes up about 10% of the antimony content.
Further drilling is planned to extend the major fault zone containing broad intervals of disseminated copper-antimony mineralisation.
Antimony
Antimony (Sb) is a designated critical mineral in many countries and is used in military applications, solar cells, fire retardants and as a strengthening agent in alloy production.
China supplies 56% of the global antimony production and has decided to restrict exports of antimony from 15 September 2024, claiming that its strategic reserves are too low to allow further exports. This has caused the price of antimony to increase significantly to approximately US$23,000/t as USA and European users seek to secure supply. (source: www.reuters.com)
Previous Results at Bulla Park
A characteristic of the Bulla Park deposit is consistency of copper and antimony grades over wide intervals (historical drilling intersected stratabound zones outside of the fault zone, where better grades are anticipated).
Table 1: Summary of historical assay results of copper-antimony mineralisationResults reported using 0.2%Cu cut-off
In previous drilling, both the copper and the antimony grades increase towards the newly intersected fault zone recently targeted by BPD09 (assays awaited). The nearest previously drilled historical hole to the fault zone is 19CA002, which includes 7m of 0.27%Sb and 0.71% Cu from 245m.*
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This article includes content from West Cobar Metals Limited, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
More Sulphides in Step Out Holes at Bald Hill Cobalt-Copper Prospect
Highlights
- The first two holes in the current diamond drilling campaign have intersected multiple broad zones (downhole widths) of sulphide mineralisation 100 – 200m away from previous high-grade cobalt drill intercepts;
- FI2612 intersected disseminated and banded sulphides (pyrite) between 70 and 110m, and semi-massive sulphides (pyrrhotite) between 110 and 129m
- FI2613 intersected disseminated and banded sulphides (pyrite) between 67 and 105m, disseminated and fracture – fill sulphides (pyrite) between 105 and 128.5m and brecciated semi – massive sulphides (pyrrhotite) between 151.9 and 185.1m
- The sulphides intersected in the current drillholes are visually similar to the high-grade mineralised intercepts obtained in Rimfire’s previous drilling at Bald Hill with assay results required for confirmation
- First assay results expected within 6 to 8 weeks as the 6-hole diamond drilling program continues
Commenting on the announcement, Rimfire’s Managing Director Mr David Hutton said: “The Bald Hill prospect continues to grow with broad zones of great - looking sulphides intersected in the latest step out holes.
The diamond drilling is helping our geologists build a detailed model for the prospect and we look forward to seeing what the rest of the program delivers.
Drilling, geological logging, and sampling is continuing, with first assays expected in 6 to 8 weeks’ time and Rimfire looks forward to providing further updates as new information comes to hand.”
Figure 1: FI2612 diamond (NQ) drill core from 112.32 to 119.45 metres showing semi- massive sulphides from 112.32 metres to 117.40 metres. The location of Figure 2 is shown by the red square.
Figure 2: Detail of semi massive sulphides around 114.40 metres in FI2612 with location shown in Figure 1 above. Brown sulphides are pyrrhotite and pale-yellow sulphides are pyrite.
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This article includes content from Rimfire Pacific Mining Limited, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
Fig Tree IP Survey Results
HIGHLIGHTS
- Induced Polarisation (IP) surveys have been completed at Fig Tree targeting hydrothermal manganese mineralisation similar to the high-grade Woodie Woodie manganese mine.
- A Dipole-Dipole IP survey (DDIP) extended over a 1,400m long northwest extension of the HD1 prospect where previous RC drill results included:1
- 7m @ 33.2% Mn from 2m (HADRC017)
- 3m @ 17.0% Mn from surface (HADRC018)
- The DDIP survey detected a number of near surface targets coincident with outcropping manganese mineralisation (34.2% Mn1) and subsurface IP responses interpreted to represent shallow down dip extensions.
- A Gradient Array IP (GAIP) survey, located about 35 km south and along strike of the Woodie Woodie mine was designed to test for mineralisation within an interpreted “Woodie” structural corridor and identified several chargeability anomalies that warrant follow-up
- The Fig Tree IP survey was co-funded to a maximum of $57,875 under the State Government’s 2024-2025 geophysics co-funded Exploration Incentive Scheme (EIS).
Surface mapping, sampling and RC drilling completed by previous explorers identified and returned high-grade manganese results from multiple prospects across the Fig Tree tenement which is located 35km south of the Woodie Woodie operations. The IP results have generated a number of targets that require infill geophysical surveys prior to drill testing.
Black Canyon’s Managing Director Brendan Cummins said:
“After the success of discovering large shale-hosted manganese deposits across the Balfour Manganese Field, the Company is now turning some of its attention to exploring for near-surface high grade mineralisation at its Wandanya and Fig Tree projects. Several prospects along the Fig Tree Manganese Trend have been mapped and drilled in the past, establishing the tenement's potential to host higher-grade, hydrothermal-style mineralisation. Its geological similarities to Woodie-Woodie and previous RC drilling have confirmed the prospectivity of the tenement, which is located only 35km south of Woodie-Woodie. Manganese deposits are often associated with chargeability anomalies which can be detected using IP techniques, so we were keen to deploy IP to the area and now have several new targets that warrant follow-up.”
Black Canyon used the high-quality historic exploration datasets at Fig Tree to evaluate the known manganese prospects, and then used this information to generate new IP survey targets. The DDIP survey has confirmed chargeable responses co-incident with outcropping manganese mineralisation and extending down dip. The GAIP surveys have also yielded several large sub- surface chargeable anomalies. Further IP surveys are planned to better resolve the size and strength of these new chargeable anomalies and establish their significance prior to refining potential drill targets in addition to other prospects across the Fig Tree tenement.
Figure 1. LHS - Fig Tree Project areas tenement showing the location of Woodie Woodie and RHS - completed DDIP, GAIP geophysical surveys and historic exploration data.
HW1 Dipole-Dipole IP Survey Results
The DDIP survey was designed to test a 1,400m long zone of subcropping manganese mineralisation along strike from the historic HD1 prospect where rockchip samples and limited RC drilling encountered medium to high grade manganese. The DDIP lines were spaced between 200 and 600m apart along the target horizon providing a cross-strike coverage between 600m and 950m.
Several near-surface chargeable anomalies, coincident with outcropping manganese mineralisation (Figure 2) and subsurface chargeable anomalies were detected with the DDIP survey. The subsurface responses are interpreted to represent shallow down-dip extensions to the surface mineralisation. are estimated to range between 10 to 25m thick from surface to depths of 50m and persist across 4 sections extending over 1,000m of strike (Figure 3) (Appendix 1).
The underlying geology is dominated by ferruginous chert and Pinjian Chert inferred to overlie close to surface Carawine Dolomite. The area is also bisected by a number of northeast and northwest trending faults and fractures. The manganese lenses form isolated subcrops 50 to 100m long and manganese disperses 20 to 40m from the subcrops.
Infill DDIP lines are required to provide more detailed chargeability mapping to resolve the potential strength and continuity of the anomalies. The HW1 target has never been drill tested and subject to further evaluation a drill program can be planned.
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This article includes content from Black Canyon, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.