Gladstone Hill Epithermal Mineralisation

Abstract

The small Gladstone Hill epithennal vein system is hosted by hydrothermally altered pyroxene andesites of Miocene age. The alteration is characterised by a propylitic assemblage which increases in intensity towards veins which comprise Fluid inclusion data obtained on surface samples shallow indicates depositing fluids were of low apparent equivalent) salinity at temperatures that reached in sections of the area below the top of Gladstone Hill), dropping to below in the shallowest The top of Gladstone Hill was then below the water-table. Late deposited calcite and sulphate produced mineral assemblages occur, the latter being particularly associated with a brecciated zone. Both assemblages probably related to the collapse of the geothermal system responsible for the mineralisation.