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South Australia – IOCG Project Overview

Petratherm have acquired tenements over South Australia’s Gawler Craton, fertile for Iron-Oxide Copper-Gold (IOCG) style mineralisation.

The Mabel Creek Project tenements (EL 6332 & EL 6333) were granted in March 2019 and comprise a total land package of 1489km2 along the prospective eastern margin of the Gawler Craton, coincident with the Mabel Creek Inlier.

The Mabel Creek Inlier is a large block exhibiting variable magnetic intensity and lies to the north of the Mount Woods Inlier which hosts the Prominent Hill Copper-Gold deposit. Importantly, depth of the overlying cover sediments in this region is minimal, with historical drilling recording the top of the prospective basement between 80 metres and 260 metres.

Multiple semi-coincident, magnetic and gravity anomalies, have been identified over both licence areas. These geophysical features have potential to be due to hydrothermal iron-oxide systems. Mineralised examples of these occur along the eastern margin of the Gawler Craton of South Australia and include Olympic Dam, Carrapateena, Prominent Hill and most recently BHP’s latest discovery at Oak Dam.

South Australia - IOCG Project Overview map

Location map of major mines, the new BHP discovery (Oak Dam) and outline of the new tenement areas overlying a regional reduced to pole aeromagnetic image (compiled from Sth. Aust. Government data).

Only minimal IOCG exploration has been undertaken across the project area, however a single hole drilled by BHP in 1992 (NC9202) testing a magnetic anomaly, 13 km south of ELA2018/198 intersected mineralised magnetite-amphibole-pyroxene rock containing significant concentrations of pyrite and pyrrhotite and disseminated chalcopyrite in massive magnetite (ref SA Govt. Records ENV08647).

The hole contained broad zones (not true widths) of anomalous geochemistry including:

  • 134m @ 626ppm Cu, 256ppm Pb, 593 ppm Zn from 96m.
  • Inc. 28m @ 0.14% Cu, 614ppm Pb, 0.23% Zn, 2 ppm Ag from 168m.

Anomalous rare earth elements were also present with values up to 1% Ce and La reported.

These results are characteristic of magnetite skarn alteration/mineralisation often found in areas around Prominent Hill and other IOCG systems further to the south and provides evidence that IOCG style alteration/mineralisation is likely to continue through the region of Petratherm’s new tenement areas.