FECT

Abstract: Altimetry gravity interpretation was carried out to delineate sedimentary basin in onshore of Timor-Leste. At least there are three major low anomaly closure have been identified and delineated along the central of country. Most of them are related to the basinal sedimentary rock derived from various sources. Hydrocarbon seepages mostly concentrated in the lowest closure of the gravity anomaly. Increasing gravity values in the north and south of the country are related to volcanic rocks of the Overthrust Terrain Association (OTA) and thrusted onto the sedimentary rocks derived from the Gondwana called the East Gondwana Interior Rift Association (EGIRA). Some anomaly areas are related to volcanic rocks that are formed because of rifting in Gondwana. Based on the two-dimensional modeling, suspected the thickest sedimentary package of EGIRA that govern petroleum system in onshore is about 5000 m. Duplex structures occurred on the EGIRA due to the collision tectonics. The duplex structures could be the main pathway for hydrocarbon migration and may act as hydrocarbon traps.

Keywords: Gravity anomaly, EGIRA, Hydrocarbon seepages, Onshore