Project Summary

The Moonta project is targeting gold-copper mineralisation in the highly prospective Moonta-Wallaroo district of South Australia’s Yorke Peninsula.

The project is centred on the historic copper mining district of Moonta-Wallaroo, which produced an estimated 355 000 tonnes of copper and around 3.5 tonnes of gold from ores averaging 3 to 4% Cu and less than 1 g/t Au. The copper (gold, uranium) deposits of Moonta-Wallaroo belong to the family of iron oxide-copper-gold or IOCG deposits, and the district is located at the southern end of the Proterozoic IOCG province or corridor along the eastern margin of the Gawler Craton. The world class Olympic Dam deposit serves as the type example, and several others of similar style occur throughout this province, notably the two important recent discoveries at Prominent Hill and Carrapateena. All of these deposits and occurrences are of similar age with key features in common, and deposits of similar style are high priority targets for ongoing exploration in the Gawler Craton.

From the 1960s to the mid 1980s, a Western Mining Corporation - North Broken Hill joint venture explored the Moonta district and numerous targets were drill tested. Their discoveries north of Moonta (Poona and Wheal Hughes) were below the joint venture size criteria, and were subsequently mined by the Amalg syndicate following a buy-out of the joint venture assets. Poona-Wheal Hughes produced 17,500 tonnes of copper and 423 kg of gold between 1988 and 1993. 

Between 1993 and 1997 the district was explored by Mt Isa Mines Ltd, again targeting copper-gold, and they were followed by BHP Minerals who were active in the district until 1999, with copper as their primary target.

Adelaide Resources acquired its initial foothold in the district in late 1993, and extended its holdings in 2003 to achieve its current position. This has given the company an overwhelming strategic advantage in this mineralised district where the geological environment is believed to remain highly prospective for the discovery of new gold and copper deposits.

From 2003 to 2006 IOCG-style copper-gold was the target of a joint venture between Adelaide Resources and the Phelps Dodge/Red Metal Ltd alliance, with the testing of several promising drill targets and over $3 million invested in the property during this period. This included 1550 metres of aircore drilling and 4074 metres of diamond drilling into targets in the Alford area, and into geophysical anomalies in the vicinity of the historic Moonta mines. In the Alford area grades in excess of 1% copper were returned from a shear zone over a strike  of some 400 metres, and a deep follow up hole intersected 0.55% copper over 30 metres.

Subsequent to this joint venture Adelaide Resources conducted several in-house studies into the exploration potential of the district, including its prospectivity for uranium. A review of all previous copper-gold exploration concluded that the potential for gold-rich end member deposits within the IOCG deposit spectrum had not been adequately tested in the field, and substantial potential remained for identifying new targets of this style. This initially involved a re-assessment of the results of previous geochemical exploration work in the district, and flagging of selected target areas for further investigation using the new gold-oriented model.

The Moonta district is a challenging exploration environment, with extensive but relatively shallow cover and minimal outcrop, apart from shoreline exposure of basement granite and gneiss. Calcrete is widely developed, and has been successfully used as a geochemical sampling medium in the past.  A new phase of geochemical exploration using calcrete sampling is underway focusing on gold anomalous areas considered to be inadequately tested by previous work.