Geology and Geophysics of Talumopatu Geothermal Manifestation Area of Mootilango District, Gorontalo Regency, Indonesia

Abstract

The research aims to assess the geothermal potential and provide a better understanding of the geology and geophysics of the area. The study utilizes various methods, including geological mapping, geochemical analysis, and magnetic and electromagnetic data analysis, to gain insights into the subsurface structures and characteristics of the geothermal system. The study area can be divided into three geomorphological units: Alluvial Plain Unit, Near Plains Unit, and Isolated Hill Unit. The study area exhibits a stratigraphy consisting of three primary units: Talumopatu granite units, Talumopatu sandstone units, and alluvial deposit units. The subsurface lithologies of the Talumopatu manifestation area were analyzed using the Wenner – Alpha configuration ERT method, revealing two distinct lithologies. The first lithology consists of sandstones with a resistivity value ranging from 4.2 to 39.0 Ωm and a thickness of 1.25 to 12.4 m, which act as a permeable layer capable of transmitting water. The second lithology is granite with a resistivity value ranging from 118 to 360 Ωm and a thickness of 3.75 to 15.9 m. This information provides valuable insights into the subsurface characteristics of the area, including the presence of permeable layers and the geological composition of the lithologies