Delineation of the Subsurface Structures in the Central Sumatra Basin (Indonesia) through Bouguer Gravity Data

This study presents the delineation of the boundaries of the subsurface structures located in the eastern part of the central Sumatra basin using Bouguer gravity data. The existence of the high gravity anomalies in the eastern part displayed in this sedimentary basin takes attention. Therefore, investigation of the reason for these high anomalies is required for the region. To this end, gravity anomalies have been processed by advanced potential field methods such as the power spectrum analysis method and tilt method. The average depths of the deep and shallow causative sources have been calculated as 23.71 km and 1.61 km, respectively. Furthermore, the boundaries of the causative sources have been determined utilizing the tilt method. The tilt map has shown that the reason for these high anomalies could be the bedrock composed of high-density material rising upwards, considering the tectonic background of the region. This study has determined that this high structure is in the form of a triple structure and that its upper depths are approximately 5.8 km, 11.30 km, and 12.8 km from north to south, respectively. As a result, it could be said that such sources with deep roots could be prospective for hydrocarbon maturation.