Evolution of Cenozoic arcs in east Java (Sunda arc, Indonesia), high Sr/Y magmatism, and melt controls on metallogeny
A convergent margin between the Indian-Australian oceanic plate and Eurasian continental plate south of Java island, Indonesia produced overlapping products of arc magmatism on the island. During Cenozoic times, the magmatic belts gradually shifted northward (further from the trench), and the main accompanying geochemical evolution is the increase in rock alkalinity through time. Quaternary subduction produces across-arc volcanoes, in which a back-arc magmatism occurs in the western part of east Java and is geochemically characterized by an increase in alkaline contents towards the back-arc side.Considering the old age of subducted slab (80-140Ma) and long duration of subduction (＞ 25 Ma),high Sr/Y adakitic rocks are surprisingly found in both igneous rocks, even in Quaternary lavas.Metallic deposits are hosted by lower and mid Tertiary volcanic rocks, and are spatially scattered within old volcanic centers (calderas) that occupy the Tertiary volcanic fronts formed approximately 200 km above the subducted slab. Igneous rocks spatially associated with most noticeable porphyry gold-copper prospects show high Sr/Y character.
Sunda island arc east Java arc magmatism metallic deposit
L.D.Setijadji S.Kajino A.Imai K.Watanabe
Department of Earth Resources Engineering, Graduate School of Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
国际会议
第八届国际矿床地质会议(Proceedings of the Eighth Biennial SGA Meeting)
北京
英文
40-43
2005-08-18（万方平台首次上网日期，不代表论文的发表时间）