Discovery and historical mining of polymetallic Ag-Bi-Pb veins associated with the Pyramid ring structure. The larger historical deposits are the Sunbeam Mine which produced 600,000 ounces of silver with grades of up to 37 kg/tonne, the Carrington Ag Bi and Pyramid Pb-Ag mines. Drilling by Endeavour at Sunbeam returned narrow veins of barite/galena and minor tetrahedrite. The highest grade intersections were 27.2m @ 290.7 ppm Ag; 11.4m @ 5.1 ppm Ag. 1999 drilling by Rhodes Mining returned 13m @ 214 ppm Ag, 7m @ 131 ppm Ag, 21m @ 29.5 ppm Ag (Wolstencroft, 1999).
More recent exploration testing of this style of mineralisation targeted the Birthday Gift and Renegade prospects where Sons of Gwalia returned results such as 3m @ 3.55% Pb, 25 ppm Ag, 12m @ 0.87% Pb, 2.36% Zn, 39 ppm Ag from Birthday Gift and 11m @ 17 ppm Ag from Renegade. Similarly at Origin Hill/Calvary Hill, Sons of Gwalia drill results include 3m @ 0.65 ppm Au, 1.2% Cu, 0.4% Pb, 0.4% Zn and 323 ppm Ag, 4m @ 115 ppm Ag; 0.4% Cu; 22m @ 17.5 ppm Ag; 1m @ 0.48 ppm Au.
At Mt Wyatt a large area of intrusive related veining and base and precious metal mineralisation has received the attention of explorers since its discovery as a large scale stream sediment anomaly by Longreach Metals in 1969. Chalcopyrite, galena and sphalerite and pyrite veinlets were intersected in holes targeting soil anomalies in altered tonalite. Scattered gold results have been returned by various companies working in the area. Best results include 2m @ 3.7 ppm Au, 4m @ 0.8 ppm Au, costeans of 1m @ 2.77 ppm Au. This system has been targeted as the periphery of a major intrusive related mineralised system.
Follow up of BCL stream sediment gold anomalies has lead to the discovery of several gold bearing mineralised systems within the proposed EPM application or just outside.
The most significant systems located to date are:
• Python: silica sericite pyrite altered fragmental volcanics returned 4m @ 2.48 ppm Au and 4m @ 4.42 ppm Au from costeans.
• Polka Dot: thin gossanous zone within volcaniclastics. Drilling of silica sulphide lode returned 8m @ 0.32 ppm, 8m @ 1.9 ppm Au.
• Mt William Philpott: quartz veinlets associated with rhyolite dykes. 6m @ 4.58 ppm Au and 15m @ 1.0 ppm Au from trenching, ditch witch results 24m @ 0.26 ppm Au.