The orebody is an epithermal gold-silver bearing quartz-adularia vein deposit. The ore veins have been dated as Pleistocene, closely related to the lower andesites of the sequence and the first overlying dacite. They fall within a 2.4 km long and 800 m wide NE-SW trending altered and mineralised corridor. The individual veins are steeply dipping (70 to 90░ NW) and are 300 to 400 m long, composed of crustiform banded quartz-adularia with subordinate smectite. They are generally 1 to 3 m thick, to a maximum of 8 m.
Hydrothermal alteration within the volcanic hosts can be grouped into four zones, namely a: i) cristobalite-smectite zone (cristobalite and/tridymite with smectite), ii) quartz-smectite zone (quartz with smectite and/or kaolin minerals, with pyrite), iii) a mixed-layer clay zone (chlorite/smectite and/or illite/smectite together with quartz, adularia, calcite, and laumontite) and iv) chlorite-illite (quartz-chlorite-adularia-calcite).