Distribution of Adakite and Adakite-like rocks and geochemical criteria for exploration in epithermal and porphyry deposits, Sunda Islands, Southeast Asia

Adakite and Adakite-like rocks are widespread and well-developed in Sunda Islands, Southeast Asia. These intermediate-acid magmatic rocks widely occur within the Central Range of Guinea Island and Owen Stanley thrust belt, northern New Guinea-Bismarck island arc, Bougainville-Solomon island arc, Sulawesi (Indonesia), Central Kalimantan, Banda island arc, as well as rare in Sumatra and western Java. Based on trace elements feature and REE curve type, the adakites and adakite-like rocks of Sunda Islands can obviously be divided into two types: the First one belongs to tholeiitic/calc-alkaline series with characterized REE curve of oceanic island arcs (O type-adakites); the second one belongs to high potassium calc-alkaline series, which can be concluded into continental type (C type-adakites), these rocks are located at arc-continent collision zone or post- collision orogenic zone. Adakites is considered to closely linked to mineralization of epithermal and porphyry deposits and is the host rocks for world-class epithermal and porphyry deposits.