Geological characteristic of geothermal manifestation in Lejja Hotspring, Soppeng, South Sulawesi, Indonesia
Adi Maulana
Departement of Geological Engineering
Abstract
Characteristic of geothermal manifestation in Soppeng Regency, South Sulawesi has been reported. The geothermal manifestation occurs as a hotspring found in five stations within volcanic Formation in Lejja area. It was generated by magmatic activity and released to the surface by the mean of geological structure activity. The hotspring water is mainly classified as bicarbonate water, particularly in station I, II and III whereas station IV and V are classified as the no dominant type. The occurrence of bicarbonate water in the research area was resulted by a reaction of mixing between water vapor from heat sources (magmatic water) with surface water (meteoric water) which increasing the bicarbonate ion in hot water. The no dominant type water in station IV and V are caused by the reaction between magmatic water and meteoric water as a heat source and the water source has experienced a large or a lot of mixing / reaction. Estimated subsurface temperature in Lejja Hotspring ranges from 368°C to 429°C and further classified as immature waters. It is shown from the study that the subsurface temperature of the research area is very high and could be the potential source to be used as a geothermal power plant in the future.
Keywords: geothermal; manifestation; Lejja; hotspring; Soppeng; South Sulawesi
Topic: Renewable Energy