Mineralogy of hydrothermal breccia cement of Humpa Leu East porphyry copper-gold prospect, Sumbawa Island, Indonesia

Indonesia is a country that has several world-class copper-gold deposits, particularly in eastern Sunda arc. The Hu’u complex prospects the surface as lithocap of extensive epithermal style alteration, but some were detected associated with porphyry beneath surface. study focuses on hydrothermal breccia cement factor influencing system district. methods used mineralogical analysis petrography and μ-XRF elemental mapping samples. district interpreted paleo-volcano; member Old Volcanics Rocks Formation. Humpa Leu East lithology consists pre-volcanics unit (lava pyroclastics), diorite, andesite-μ-diorite, tonalitic intrusion at depth. Hydrothermal alteration evolved from tonalite body to outward, consist potassic, inner propyllitic overprinted by phyllic advanced argillic. Several phases activities occur this system, including phase fluids. least have three assemblages possibly mineralization. assemblage HLE quartz-feldspar-plagioclase-biotite high-temperature phase; then followed epidote-sericite-chlorites-anhydrite-carbonates medium temperature; there are aluminum-rich clay minerals gibbsite. Mineralization occurs chalcopyrite-magnetite, bornite-chalcopyrite chalcopyrite-sphalerite phases. occurrences chalcopyrite all indicate stability intermediate sulfidation proses possible answer abundant copper fluid