Perpustakaan Digital ITB

Sixteen samples of Late Eocene Kiliran and Talawi oil shales from Brown Shale Formation (Kiliran Basin) and Sangkarewang Formation (Ombilin Basin), respectively, Indonesia were collected from two drill cores. Total organic carbon (TOC) and x-ray flourescence (XRF) analysis have been carried out to investigate the correlation between major elements and organic matter contents in the oil shales. Kiliran and Ombilin oil shales have potential to generate shale oil as indicated by TOC of about 12.21% and 4.99%, respectively. TOC values increase with drilling depth increment in both oil shales. This indicates that deposition occurred in the deep depositional environment in early deposition, with Ca and S elements as indicators. Both elements considered as autochtonous input indicators because of their similiarity in tendency with TOC toward drilling depth. On the other hand, Si, Ti, Al and K elements are terrigeneous input indicators that tend to have less concentration with drilling depth increment. This indicates basin shoaling during the oil shales depositions.