SUBSURFACE INTERPRETATION AND STRUCTURE DELINEATION OF THE MUNA-BUTON BASIN BASED ON TOPEX SATELLITE IMAGE GRAVITY ANOMALY DATA

• Main Author: Nur Ahsan Zakir, Muhammad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/78918
• Institution: Institut Teknologi Bandung

Buton Island was formed as a result of intense tectonic processes, resulting in a variety of geological resources, one of which is the natural resources of oil and gas which accumulate in a sedimentary basin. Research has been carried out on gravity field measurements to interpret the subsurface structure in the Muna-Buton Basin. The data used is free air gravity anomaly data, so you only need to carry out Bouguer corrections and terrain corrections to obtain complete Bouguer anomalies. Anomaly separation is carried out using several methods, namely moving average, surface trend analysis, and upward continuation. Next, gradient analysis was carried out on the residual anomalies to delineate the basin structures in the study area using several methods, namely horizontal gradient, total gradient, tilt-angle horizontal gradient, and improved logistic filter. Complete Bouguer anomaly in the Muna-Buton Basin area, ranging between 30 – 160 mGal. In general, the distribution of Bouguer anomaly patterns in the study area has three different trends. The first anomalous trend has a high anomaly pattern in the North to East areas. Furthermore, there is a moderate anomalous trend which is shown to be dominant in the Southwest to Central regions. Meanwhile, the dominant low anomaly pattern is spread from the East and tends to lower towards the West. Qualitatively, there are two sub-basins that can be delineated, namely sub-basin A which is in the East and sub-basin B which is in the West. Sub-basin A, if correlated with Davidson's reconstruction model, is the Bulu sub-basin, while sub-basin B is the Buton Strait sub-basin. There is a basement layer which is indicated to be at the shallowest depth of 2 km in the Buton Strait sub-basin and the shallowest depth of 3 km in the Bulu Basin sub-basin. The depth of the basement layer deepens towards the center of the basin until it reaches more than 4 km.