Total historic hard rock gold production from Walhalla
of 1,510,309 ounces at a recovered grade of 33.59 g/t Au.
Dozens of high priority exploration targets
including former mines most with no modern drilling or exploration.
Faulted dyke structures
have same age of mineralization as Fosterville and elsewhere in the Melbourne zone.
- The Walhalla license application includes the Cohen’s Reef with a past production of 1,479,851 oz from 1,429,298 tonnes at an average grade of 32.2 g/t Au (GeoVic, 2020).
- The production at Cohen’s Reef came from a single mineralized shoot mined to 1120m depth.
- Mineralization was controlled by the steeply west dipping Cohen’s Shear zone, which was reactivated during gold mineralization in the Middle Devonian Tabberabberan orogeny. This is the same age mineralization as Fostervillle and elsewhere within the central Melbourne zone.
- The known extent of Cohen’s Reef is approximately 1500 metres long and 1134 metres deep, along the valley of the township of Walhalla.
- The extensive and continuous reef is predominantly a laminated quartz-carbonate vein with some associated stockwork veins, and in places incorporates sheared dyke and meta-sedimentary rocks.
- The reverse fault lies along the margin of an extensive but narrow dyke, within a complex fifty-metre-wide shear zone. Gold mineralization is mainly in laminated quartz veins in the reverse faults, associated with pyrite, arsenopyrite, galena and stibnite.
- Pyrite alteration envelopes extend to 10m into the host rocks, while more abundant arsenopyrite extend 2m.
- Historical production along Cohen’s Reef concentrated on visible gold within the laminated reef system.
- Recent assay results have highlighted the increased levels of visible gold, and the presence of disseminated gold, especially along dyke margins.
- The ten highest hold assay results (5-12 g/t) from recent drilling in proximity to Cohen’s Reef are found in laminated veins within or on the margins of dyke; or in laminated or brecciated veins within meta-sedimentary rock, predominantly shale (Goldstar, 2007).
- Historic mine plans indicate mineralization at Cohen’s Reef remains open at depth