Project Summary

Adelaide Resources has been exploring its Eyre Peninsula tenements since soon after its listing in 1996, and has been a major player in the emergence and recognition of a new gold-bearing province, referred to as the Central Gawler Gold Province, in the Proterozoic basement rocks on Eyre Peninsula. The result for the company was the discovery of two new and significant occurrences of gold mineralisation, at Barns and Baggy Green, and a new appreciation of the prospectivity of this basement terrain.

The Barns discovery was made public in March 2000, and was the outcome of test drilling of a coherent soil calcrete anomaly with a peak value of 49ppb gold. Follow up drilling defined a mineralised corridor around 100 metres wide containing brecciated, veined and altered granitic bedrock occupying a mineralised zone with a moderate to shallow westerly dip. This zone returned wide intersections with anomalous gold, (eg 21 metres at 0.75g/t Au from RCBN-66), and higher grades associated with narrow quartz-pyrite-sericite veins, (eg 1 metre at 12.5 g/t Au from RCBN-52). Copper, lead, bismuth and silver are also locally anomalous. The body is best described as a mineralised sheeted vein system in the hanging wall of a major west-dipping shear or thrust zone.

The Baggy Green discovery is located around 5 km east of Barns, in a similar geological environment, and was made public in April 2004. It was also initially defined as a robust soil calcrete anomaly with follow up drilling intersecting significant gold mineralisation in weathered gneissic bedrock.  The subsequent drill-out defined a zone of elevated gold values over a strike of some 2.6 km with primary gold mineralisation in gneissic bedrock of similar character to Barns.  The mineralised vein system is again underlain by a footwall shear or thrust zone with a shallow dip (20° to 30°) to the west.

A well-defined mineralised zone some 30 metres thick and with a strike of around 200 metres was outlined in the centre of the deposit, by intersections such as BGRC 865 that returned 24 metres at 2.33 g/t Au, including 5 metres at 9.01 g/t Au from 66 metres. This higher grade interval also contained 1 metre at 35.1 g/t Au, reflecting intersection of high grade mineralised veinlets occupying a fracture zone. 

Preliminary scoping studies of Baggy Green have shown that it is sub-economic as currently defined, but potential exists for nearby extension and repetition. Evaluation of this possibility is part of the ongoing work program for the Project.

The region is characterised by very poor bedrock exposure with extensive sand and calcrete cover, as well as sediments contained in an extensive Tertiary palaeochannel system, (prospective for uranium).  Systematic sampling of soil calcrete for gold and other elements outlined numerous discrete gold and copper anomalies throughout the tenements, many of which have undergone at least a preliminary drill test. The Barns and Baggy Green discoveries have now provided a model of gold occurrence for this terrain that can be more widely applied to guide a more intensive follow up exploration phase over the previously defined anomalies. 

There have been major advances in the understanding of Gawler Craton geology and the overlying regolith and Tertiary cover since the company started its Eyre Peninsula gold exploration in 1997. A new generation of geophysical data sets are also available, most notably a detailed high resolution aeromagnetic survey flown over the company’s tenements in late 2004 by a joint venture partner just prior to withdrawal. The company’s tenements are also included in the area covered by new and more detailed gravity surveys conducted by PIRSA in 2005.

A consequent review by the company of its previous exploration has generated new and more refined interpretations of previously targeted anomalies, and new target possibilities. Effectiveness of calcrete sampling has also been shown to be variable throughout the terrain, and this data set is also being re-assessed to extract and re-interpret the lower level anomalies, or ‘weaker signals’ in the data.
The Eyre Peninsula Gold Project is therefore entering a new exploration phase, building on the results and lessons from two significant discoveries (Barns and Baggy Green), and directed at a new generation of targets. The company believes that the tenements continue to be highly prospective, and that the pathway to further success is a combination of innovative geology with leading edge exploration technology.