Hydrothermal Alteration Associated with the Gosowong Epithermal Au-Ag Deposit, Halmahera, Indonesia: Mineralogy, Geochemistry, and Exploration Implications

摘要

The Gosowong epithermal Au-Ag deposit, located on Halmahera Island, eastern Indonesia, has a resource of 0.99 million metric tons (Mt) at 27 g/t Au and 38 g/t Ag. Host rocks consist of Miocene shallow marine, intermediate-basic volcanic and volcaniclastic rocks. The structural setting consists of an elongate dome with associated tensional fracturing trending parallel to the long axis of the dome. Gold mineralization is hosted within multiphase, epithermal quartz-adularia and quartz-chlorite fissure veins, breccias, and stockwork veining within two gently south plunging ore shoots along a 400-m section of the north-striking, east-dipping Gosowong fault.