Petrogenesis Of Bawean Island In Lake Kastoba Area And Surrounding, Bawean Island, East Java: A Preliminary Study Based On Geochemical Data Muhammad Hafizh (a), Mirzam Abdurrachman (a), Muhammad Bahrun Najah (a)
(a) Geological Engineering, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia
Abstract
Bawean Island is one of the islands with volcanoes in the Java Sea, north of Java Island. It is known that the rocks there has a high alkaline content. If seen from the position of Bawean Island, it is estimated that Bawean Island is still related to the subduction between the Indo-Australian Plate and the Eurasian Plate which occurs in the south of Java Island. To ensure the tectonic setting on Bawean Island, a petrogenesis approach is used using rock geochemical data. Geochemical data were obtained through analysis using XRF (for principal components) and ICP-MS (for trace components). The content of chemical compounds and discriminant diagrams are used to determine the tectonic order with parameters in the form of main components and trace components. Based on the plot results of the discriminant diagram of trace components in the form of TiO2/10-P2O5-MnO, Ti-Zr, and TiO2 content <1.3%, Bawean Island is included in the tectonic setting of a calc-alkaline island arc.
Keywords: Geochemical- Petrogenesis- Bawean Island- High potassium
