GEOTHERMAL POTENTIAL OF KADIDIA, CENTRAL SULAWESI BASED ON GRAVITY MODELING

• Main Author: Huda Pinandita, Aulia
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68710
• Institution: Institut Teknologi Bandung

Geothermal manifestations such as hot water and alteration rocks are found in South Kadidia, Central Sulawesi. Geothermal fluids in the Kadidia area are affected by magmatic fluids with an estimated percentage of ±10 – 20%. Seismic activity in Lake Lindu and the presence of a segment of the active Palu Koro fault movement, is estimated to be the controller for the formation of the geothermal system in the Kadidia area. Therefore, a study of gravity data was carried out using the observation of gravity values obtained from PSDMBP with distances between points varying from 250 to 1500 m, to be able to describe the geothermal system in the Kadidia and South Kadidia areas. Gravity data processing is carried out by calculating the complete Bouguer anomaly, separating regional and residual anomalies with polynomial trend surfaces, upward continuation, and moving averages, and interpretation through forward modeling and inverse modeling. Based on the processing and modeling of gravity data in the Kadidia and South Kadidia geothermal areas, it is known that the Tineba volcanic rock formation is estimated to be a heat source, indicated by a positive density contrast value, as well as the granite layer above it which is heated by the heat source into a conductive heat zone that shown with a positive density contrast value as well. Meanwhile, fractured granite is indicated by a negative density contrast value, which is expected as a reservoir of geothermal energy in the Kadidia area. With magnetotelluric models and geochemical studies, the Kadidia and South Kadidia geothermal systems are known to have different reservoirs, this is indicated by different density values in the southwest and northeast of the study area as a result of forward modeling and inverse modeling.