Granitoid and associated ore deposit in Sulawesi, Indonesia
Late Tertiary granitoid body extends from the southern part of West Sulawesi Province of Sulawesi Island to the central part of the Northern Sulawesi Province; occupying a length of approximately 1600 km, where they built up an outstanding West to North Sulawesi Granitic Belt. Two groups of granitic rocks can be classified according to their geochemical characteristic.
The granitic rocks in the West Sulawesi Province formed the West Sulawesi Suites (WSS) consists of granite, monzonite, quartz monzonite and granodiorite with dioritic enclave showing metaluminous, I-type and mostly ilmenite-series granitic rocks (reduce I-type) character which represents continental margin, high-K calc-alkaline (CAK) to shoshonitic magmatic arc developed in extensional, post-subduction tectonic setting with asthenospheric upwelling providing perturbation and adiabatic decompression.
The granitioid from the North Sulawesi Province formed the North Sulawesi Suites (NSS), range from tonalite to granite through granodiorite, metaluminous and normal I-type character (magnetite-series), represent subduction of lower crust segment of oceanic origin with less contamination of sediment material. Both granitoid suites are associated with ore deposit. The WSS suites consists of small deposit of epithermal Au-Cu system and base metal mineralization whereas the NSS suites related with porphyry Cu-Au-Mo and epithermal Cu-Au system.
