Geology

• 500 Million Years Ago- Most of Eastern Australia including the Reserve was deep beneath the ocean some hundreds of kilometers east of an older continent. Sediments were deposited on the ocean floor to form the present day Pinnak Sandstone found around the region.

• 400 Million Years Ago- Compression of the ocean floor resulted in folding and the emergence from the ocean floor of the Pinnak Sandstone. Granite bodies such as Mt Buffalo intruded and metamorphosed the sediments. High pressure brines dissolved tiny amounts of silica and metals including gold, and were forced towards the surface depositing quartz and gold into faults and fractures forming veins and reefs.

• Last 100 Million Years- Uplift and river erosion has worn down several kilometers of Pinnak Sandstone including many gold bearing reefs and veins.

• The Last 1 Million Years- The geology of the region has changed little. Snow melts through various ice ages have produced floods and reworking of the alluvial deposits, rounding boulders and pebbles in the rivers and concentrating gold into deeper channels.

• Today the Reserve is made up of alluvium from the Ovens River as a result of the intensive gold mining of the 19th century. The miners left stacked banks of boulders and pebbles, small shafts, and water races.