Pustaka Ilmiah Universitas Padjadjaran

Abstrak

Metamorphic Rocks in Bayah Complex, Banten Province: A Study in Tectonic Environment

Based on earlier research, metamorphic rocks in Bayah Complex and in its surrounding area are comprised of various types of rocks with different degrees of metamorphism (low to high grade metamorphism) and protolith. The focus of this research is to determine the tectonic environment for these rocks by petrographic and geochemical analysis. The petrographic analysis showed that the metamorphic rocks are comprised of muscovite biotiteschist, biotite schist, garnet muscovite biotite schist, actinolite schist, epidote amphibolite schist and hornblende schist. Most of them showed foliation, with poor foliation in some area. Based on mineral assemblages, they are dominated by greenschistfacies to greenschist at the upper part, with some epidote amphibolite facies. The geochemical analysis showed that metamorphic rocks in the research area is associated withcalc – alkaline magma series, calc – alkali basalt and oceanic island alkali basalt, the magma type which characterized a subduction related magmatic origin. Based on these results, the metamorphic rocks in Bayah Complex is interpreted to have an association with subduction zone.