The Bowdens Silver Deposit is a low sulfidation epithermal silver-base metal deposit that has formed on the northern margin of a hydrothermal system within air-fall breccias, ignimbrites and crystal tuffs of rhyolitic composition. The deposit lies near the north-eastern margin of the Lachlan Fold Belt and the rhyolitic host rocks are of Early Permian age. The silver mineralisation occurs as flat-lying zones of disseminations and silicic fracture-filling within the Rylstone Volcanics and is closely associated with sulfides of iron, arsenic, lead and zinc. High-grade silver mineralisation is also found in steeply-dipping fracture zones which host banded sulfide veins. Studies of the alteration products indicate that high temperature fluids, flowing from south of the current project area, resulted in quartz (adularia) - illite/sericite alteration. Cool, low pH steam-heated waters on the northern and eastern margins of the prospect area resulted in siderite - smectite-illite clay - Fe-carbonate - marcasite - kaolinite alteration. Mixing of the two fluid types resulted in the deposition of iron and base metal sulfides, a decrease in both sulfur activity and pH of the mineralising fluid, and subsequent silver mineralisation.