Java volcanic arc: what lies beneath? the overlooked subvolcanic petroleum potential in Java Island.

Java is an active volcanic arc that resides in the southwestern - southern boundary of Sundaland edges. The volcanic arc consists of several volcanism episodes, with a relatively younging trend northward (Late Oligocene to Pleistocene), following the Indo-Australian plates inward migration. In contrast to the prolific neighboring basins in the Northern edges of Java Island; the basin reconstruction and development in Bogor to Kendeng Troughs are overlooked and lays bare the challenge to the seismic imaging due to the immense Quaternary volcanic eruption covers. However, oil and gas seepages around the North-Central part of the Island confirmed the active petroleum generation. Five focused window areas are selected. A total of 1,893 Km sections, 584 rock samples, 1569 gravity, and magnetic data, and 29 geochemical samples (rocks, oil, and gas samples) were acquired during the study. Both Bogor and Kendeng Troughs are active petroleum systems that generate type II /III Kerogen typical to the reduction organic material derived from transition to the shallow marine environment. The result suggests that these basins are secular from the neighboring basins, The Northwest and Northeast Java Basins, characterized by oxidized terrigenous type III Kerogen.