MODELING OF GEOTHERMAL SYSTEM BASED ON GRAVITY DATA OF TALU – TOMBANG, GEOTHERMAL FIELD, WEST SUMATERA, INDONESIA

• Main Author: Oktada Hilman Lafayto, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/53158
• Institution: Institut Teknologi Bandung

West Sumatra which located along the volcanic arc made its region has geothermal potential. Talu – Tombang, West Pasaman, West Sumatra, Indonesia geothermal field is one of the area that has geothermal system also located along the volcanic arc in Sumatera. Therefore, geophysics exploration is needed in order to have a better view about geothermal activity also geological setting in that area. The purpose of this research is to determine the model of geothermal system that develops at the Talu – Tombang geothermal field based on gravity data. In this study used data in the form of a Complete Bouguer Anomaly data of Talu – Tombang geothermal field in 2012. The CBA data was gridded using 250 interval to a Complete Bouguer Anomaly digital map. The separation of regional and residual anomalies was carried out using the moving average method and spectral filter method using 1D & 2D spectral analysis. The 2.5D modeling results show that there is a high anomaly at the center of the Talu – Tombang geothermal field area. The emergence of the high anomaly is interpreted as pliocene granodiorite intrusions which become the heat source of hot water manifestations. The reservoir in Talu – Tombang area is sandstone with averaged thickness of 1,2 km. Cubadak pyroclastic lava become the caprock in Talu – Tombang area.