Advancing Geothermal Exploration With 2D Magnetotelluric and 3D Modeling: Case Study From Mount Parakasak, Banten, Indonesia

Mount Parakasak in Banten hosts promising yet underexplored geothermal resources. This study integrates two-dimensional magnetotelluric (MT) and time-domain electromagnetic (TDEM) surveys with three-dimensional inversion modeling to delineate subsurface resistivity structures and characterize the geothermal system. Thirty-six MT soundings, corrected for static shift using TDEM data, were inverted to generate 2D resistivity sections and interpolated into a 3D resistivity volume constrained by geological and geochemical datasets. Results reveal a conductive clay cap (~100 Ω·m) and an upflow zone near the Kaipohan manifestation, associated with reservoir temperatures of 240–260 °C. The Batukuwung hot spring marks an outflow zone at 52–75 °C. Integrated modeling supports the presence of an active geothermal system with drilling targets at ~1500 m depth. These findings provide quantitative guidance for exploration and resource assessment, advancing geothermal development in Banten Province.