Isa Undercover Copper-Gold

Isa Undercover Initiative (SER 100%, Queensland)

The greater Canobie and Isa North projects –  jointly referred to as the ‘Isa Undercover Initiative’, comprises both the Eastern and Western Mt Isa Succession, two major undercover extensions (more than 2,500km2) of the Mt Isa Province, which is one of the most highly mineralised copper-gold provinces in the world.

Above: The location of SER’s “Isa Undercover Initiative” projects within the Mt Isa Region

The Canobie Project now consists of eight exploration licences (1837km2) that encompasses an entire belt of the northern Mt Isa Eastern Succession, home to mines such as Evolution Mining’s giant Ernest Henry Copper-Gold mine. SER is convinced Canobie represents an extension of the Cloncurry Iron Oxide Copper-Gold province. Less than 30 drill holes in the entire district have penetrated Proterozoic basement and these include multiple high-grade gold hits, significant Ni-Cu sulphide intercepts and numerous intersections of copper, zinc and uranium mineralisation within intensely altered rocks that have never been followed up. This extraordinary strike rate from a limited number of holes led SER to secure the entire belt.

The Isa North Project comprises three exploration licences covering an underexplored 976km2 belt located along the projected northern extension of the mineralised Mt Isa – Gunpowder Fault Zone. Several large deposits lie on or adjacent to this fault system, including the Mt Isa, Mt Oxide and Gunpowder copper deposits and the Mt Isa, Hilton and George Fisher lead-zinc-silver deposits. In December 2020 the tenement transfer process was finalised, and SER has already begun a review of the geophysical data covering the project area.

Canobie Project – Kalarka Prospect Drilling Campaign

The Kalarka Prospect, within EPM27378 of the Canobie Project, is a a discrete 750 x 600m, 40nT aeromagnetic response characterised by an elevated Electromagnetic (EM) response and partially coincident anomalously higher density. SER has modelled a steep westerly dipping plate as the source of the EM response.

During October 2021, SER completed two diamond drill holes, which were collared 535m apart and totalled 1574m of drilling, designed to test the Kalarka Prospect. This drill program was awarded a Queensland Government Collaboration Exploration Incentive (CEI) grant worth $100,000 in direct operational funding.

Drill holes CNDD001A and CNDD002 both intersected mafic / ultramafic intrusive units with disseminated and semi-massive magmatic sulphides as shown below. The drill holes contain inherent similarities in host rocks and sulphide mineralisation style to the nearby Tea Tree Nickel-Copper Sulphide Prospect which recorded a 10.4m intersection at 0.25% Nickel and 0.28% Copper in drill hole TT001D, located approximately 2.75km southwest of Kalarka. The best intersections included;

  • CNDD001A:
    • 132m of disseminated Ni-Cu sulphides within ultramafic @ 0.1% Ni from 507m including 2m @ 0.68% Ni, 0.17% Cu (from 635m)
  • CNDD002:
    • 43m of disseminated Ni-Cu sulphides within ultramafic @ 0.1% Ni from 615m and 0.6m @ 0.96% Ni, 0.11% Cu (from 661.6m)
Above: Semi massive sulphide intersected in CNDD001A at 662.1m (part of 0.6m interval containing 0.96% Ni)

SER is highly encouraged by the significant intervals of ultramafic rocks coupled with an increase in nickel grade over a greater length within the sulphide zone which demonstrates, at a local scale, the potential for accumulations of nickel sulphides to occur within a sulphur saturated magmatic system. This advances the potential of the region to host significant Ni + Cu sulphide mineralisation as broad zones of thick nickel and copper-bearing disseminated sulphides can be associated with more massive accumulations, as demonstrated between Western and Eastern Deeps systems at Voisey’s Bay (Labrador, Canada) and within the Nebo-Babel deposit (West Musgraves Ranges, W.A.).

Furthermore, a revised interpretation of the detailed gravity data at Canobie shows that it maps mafic units across the project area and reveals that both the Kalarka and Tea Tree prospect form part of a larger ore junction. Importantly, extending north and south from the main ore junction are elongate gravity features interpreted as ribbon-like “chonolith” intrusions which have the potential to host higher tenor nickel-copper sulphide mineralisation.

Above: Left: Drill holes intersections surrounding the Kalarka Prospect over a Bouguer Gravity Image. Right: Reduction to Pole Magnetic Image. Note the elongate density highs (interpreted chonoliths) extending north and south from the ore junction.

Future Work

A complete review of the project is underway.  This includes re-logging all available drill core, selected additional geochemical analysis, and petrology and petrophysical data collection to map the lithochemical signatures and allow vectoring into more prospective portions of the intrusive system.  An immediate outcome from the review was the reinterpretation of available gravity data across the project area in the search for similar “ore junction” gravity anomalies. Located approximately 50km to the south west of the Tea Tree Prospect an analogous gravity anomaly was identified on the southern margin of the Canobie project which has since been secured (EPM28180).

Deep Learning Based Geological Interpretation of Geophysical Data

As part of an ongoing partnership with award-winning mineral exploration machine learning pioneers Caldera Analytics, a joint 2021 CEI submission to develop a deep learning-based model to interpret basement geology from geophysical data was awarded a $65,000 grant.

Caldera proposes to develop a deep learning model that performs lithology interpretation based on the existing geophysics of the Isa Undercover area, ultimately to further advance the concept of “live geological interpretation”, one that is not static, but rather one that adapts and changes as more data is acquired whilst SER advances exploration of the Isa Undercover Initiative.

SER would like to thank the Queensland Government for their support which validates our targeting methodology.

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