J. Polii, W. Wantalangi, B. Tambahani, R. Ratumbuysang
The appearance of manifestation characterizes the existence of geothermal potential. This research was conducted in the Kaleosan area of North Minahasa Regency, in North Sulawesi Province, Indonesian, which has a manifestation of hot water with a temperature of 90 C with pH of 6.89, and there are silica deposits around it, all of which are characteristics of a water-dominated geothermal reservoir. This research was carried out by analyzing the characteristics of the surface fluid samples of the Kaleosan hot water manifestations. Analysis of fluid characteristics using the Q-SO4-HCO3and Na-K-Mg. From the Q-SO4-HCO3diagram, it is found that the geothermal fluid in Kaleosan is a type of chloride. The high chloride content is thought to be due to the increase in geothermal fluids containing CO2and condensing in shallow aquifers. From the Na-K-Mg diagram, it is obtained that the Kaleosan hot springs are immature water where this manifestation fluid has undergone dilution and cooling by meteoric water during its trip to the surface. From the quartz silica geothermometer, the reservoir temperature estimate is 236.6 C, which indicates that the geothermal reservoir in the Kaleosan area is a high enthalpy geothermal system. © Published under licence by IOP Publishing Ltd.
Physics Department, Mathematics and Sciences Faculty, Manado State University, Manado, Indonesia