The Carinya-Koppio-Tumby Bay project has been previously explored for uranium, base metals and iron ore on a reconnaissance basis and contains sporadic outcrops of Hutchison Group quartzite, marble, calcsilicate gneiss, BIF, garnet gneiss and amphibolite. Outcrop is more extensive in the east but much of the region is capped by intense Tertiary weathering and ferricrete that mask basement lithologies.
Hutchison Group outcrop extends from Port Lincoln on the western side of the Kalinjala Mylonite Zone to north of Lipson and Koppio. To the east of the mylonite is undifferentiated Lincoln Complex granite gneiss (Donnington Granitoid Suite) and amphibolite. A 1400m x 600m gabbro (Coonta Gabbro) intrudes the Lincoln Complex just west of Tumby Bay.
There are several historic mines in the Koppio-Lipson area along with high-grade iron ore, anomalous uranium, gold and base metals. The Tumby Bay, Flinders and Port Lincoln mines are located mainly within outcropping marble and BIF of the lower Hutchison Group (Katunga Dolomite and Lower Middleback Jaspilite equivalents) immediately adjacent to and just within the Kalinjala Mylonite Zone. Each of these mines produced a few tonnes of mainly high-grade copper carbonate ore but copper sulphides have been recorded from deeper levels.
The uranium potential of the region is still largely untested. Several radiometric anomalies have been identified near Carinya, Koppio West, Pillaworta, Koppio East, White Flat and an area 5km northwest of Louth Bay. Widespread uranium anomalism has also been recorded in the lateritic regolith.
The area northwest of Louth Bay includes a spot sample with 0.15% U at 15.3m depth in drillhole TBD4. This area is along strike from Hospital, Frasers and other prospects in the Port Lincoln area and is in retrograde altered granite gneiss immediately adjacent to the Kalinjala Mylonite Zone. This 40km-long alteration zone is a high priority uranium target.
A detailed radiometric survey at Carinya defined a large (ca. 800m long) uranium-only anomaly that has been largely untested. A strong uranium radiometric anomaly also occurs at Koppio where drilling has identified trace gold up to 50ppb Au and anomalous uranium up to 0.026% U.
The Coonta Gabbro (or Tumby Bay Nickel Prospect) has been the target of nickel-chrome exploration based on elevated rock chip and stream sediment samples. Basic to ultrabasic diorites to peridotites crop out over an area of 0.7 km 2 with up to 0.2% Cr and 0.15% Ni.
