Argent Minerals has reported that the Loch Lilly drilling programme will commence during the week of the 17th July, testing two identified targets in the Loch Lilly Kars Belt in western NSW, both having geophysical signatures indicative of large scale porphyry copper deposits.
The Loch Lilly – Kars Belt, located approximately 80 kilometres south of Broken Hill, is considered to be a an extension of the Mount Read Volcanics Belt in western Tasmania, which hosts several world class mineral deposits. These include Mt. Lyell, to date producing more than 62 tonnes of gold, 1.8 million tonnes of copper and 1,300 tonnes of silver, and major VHMS deposits at Rosebery, Que River and Hellyer featuring high grade silver, lead and zinc.
The Mt. Read Volcanics Belt also includes the shear-hosted Henty gold mine, which has produced more than 1.5 million ounces of gold. Poorly exposed in western Victoria, the same broad belt hosts the Stawell gold mine that has produced more than 2.5 million ounces of gold. Two identified targets in the Loch Lilly – Kars Belt, Eaglehawk and Netley, will each be drilled by a 500 metre diamond hole.
ABOUT THE EAGLEHAWK TARGET AND DRILLHOLE ALE001
Eaglehawk is one of four ‘walk-up’ target areas defined in the Loch Lilly – Kars Belt JV area by a collaborative effort between Anglo American Exploration (Australia) Pty Ltd (AngloAmerican) and Dr. Anthony Crawford during 2014/15. AngloAmerican completed a 3D interpretation of the available aeromagnetic data and a 501 station infill ground gravity survey on tenement EL8199, where four historical holes had been drilled.
New lithogeochemical and geochronological data was obtained from these drillholes and analysed by Dr. Crawford. Encouraged by strong fertility signals together with skarnoid and calc-potassic alteration revealed by the drill core analysis, AngloAmerican conducted the first global trial of an in-house magnetic-induced polarisation (MIP) geophysical survey.
The survey, which was conducted over an area in the central section of EL8199 that included the four historical holes, detected several significant resistivity-chargeability anomalies that remain untested to date. These anomalies were to be the focus of future drilling until AngloAmerican cancelled all metals exploration in Australia in August 2015 as part of the company’s global balance sheet restructuring programme.
After entering into the joint venture with Dr. Crawford, Argent is now continuing this work as manager/operator, with the right to earn up to a 90% interest in the project. Argent will earn a 51% interest by completing this drilling programme.
Drilled for 500 metres at a dip of 70° in the 290° azimuth direction, diamond hole ALE001 has been designed primarily to test the most compelling MIP chargeability high anomaly that is also coincident with both a magnetic high ridge and a residual gravity high.
Hole ALE001 will test the interpretation of the denser, more magnetic features of known basalt and andesite units and a possible interaction with a fertile porphyry intrusion which would be responsible for intersected skarn mineralisation in historical drillhole NBH004
ABOUT THE NETLEY TARGET AND DRILLHOLE ALN001
The Netley target was defined through 3D modelling performed by AngloAmerican on a dataset comprising a 400 station ground gravity survey, a magnetic survey, and historical drill core. Inversion modelling was conducted on available geophysical data to improve the resolution and depth expression of the magnetic response.
The modelling revealed near-coincident magnetic high and gravity low anomalies reminiscent of the scale and detail of the Northparkes mineralised finger porphyries rising from a basal monzodiorite pluton, and that the historic drilling failed to intersect the magnetic source body.
The target remains untested to date. At a 70° dip toward the northwest (315° azimuth), drillhole ALN001 has been designed to intersect the discrete magnetic high feature illustrated. This hole design also complements the test of the magnetics feature by drilling across the end of the gravity high ridge in the gravity low area.
ABOUT THE LOCH LILLY – KARS BELT PROSPECTIVITY
The new lithogeochemical and geochronological data obtained during the 2014/2015 analysis of the drill core from the 10 historical drillholes in the Loch Lilly – Kars Belt confirmed the interpreted correlation of this belt with those exposed in western Tasmania and western Victoria.
The impressive mineral endowment of this belt of rocks in western Tasmania and Victoria is the single best justification for exploring poorly known, even more poorly explored sections of the same geological domain further north in the exploration-accessible Loch Lilly – Kars Belt.
An unexpected bonus of the studies was the revelation that high-level monzodiorite-monzonite intrusives and andesite porphyries in a number of these historical drillholes, historically assumed to be of Middle Cambrian age, are in fact Late Silurian – Early Devonian, with ‘fertile’ lithogeochemical signatures for porphyry copper-hosting intrusions.
These later granites are responsible for the Mt Bischoff (10.54 Mt @ 1.1% Sn) and Renison Bell (24.54 Mt @ 1.41% Sn) tin deposits, and the Avebury nickel deposit (29.3 Mt @ 0.9% Ni) in Western Tasmania. A significant outcome of the analysis performed by Dr. Crawford, AngloAmerican, and Argent is that the Loch Lilly – Kars Belt geology is prospective for volcanic-hosted massive sulphide (VHMS) and porphyry copper-gold, with further prospectivity of Sedex silver-lead-zinc, nickel sulphide and sedimentary copper.
ABOUT THE NSW GOVERNMENT 75% CO-FUNDING
The direct per-metre drilling costs of the drilling programme are 75% co-funded by the NSW Government to a maximum of $150,000. The highly sought after Government funding was awarded to the project based on project prospectivity and technical merit as assessed by an independent expert advisory panel.
All three of Argent’s main projects have been awarded NSW Government Cooperative Drilling funding grants, based on project prospectivity and technical merit as assessed by independent expert panels appointed by the NSW Government.
ABOUT THE DRILLING PROGRAMME SCHEDULE
Site preparations are currently underway. The drilling contractor is currently scheduled to mobilise to site for drilling to begin during the week of the 17 July 2017. The drilling programme is scheduled to operate on a 24/7 basis, and is expected to be completed within a 3-4 week period, subject to drilling conditions and weather. Drill core logging and sampling will be conducted at a facility in Broken Hill for maximised efficiency.