The Application of Geochemical Ternary Diagram to Analyze Characteristics of Geothermal Waters in Sumatera Island, Indonesia
CHENCHEN, Yuniar Zhafira ABDILLAH, Muhamad Firdaus AL HAKIM, SURYANTINI, Mochamad NURHADI
[Institut Teknologi Bandung (ITB), Indonesia]
There are a lot of geothermal prospects reported in Sumatera Island, Indonesia. Most of those geothermal prospects are still in an exploration stage to understand their geothermal system with geological, geophysical, and geochemical surveys. Geochemical surveys are usually used to analyze the characteristic of water, gas, or soil manifestations, geothermometers, and type of systems. This study utilizes water geochemistry to calculate geothermometers while considering equilibrium of fluid, analyze characteristic of water manifestations, and its correlation to the Great Sumateran Fault. This study focused on the evaluation of water geochemistry with Cl-SO4-HCO3 ternary diagram, Na-K-Mg ternary diagram, and ratio of another geoindicator to know its association in either deep or shallow levels, compare equilibrium temperature, and water geochemical characteristics between each geothermal prospects in Sumatera Island. The results of this study show that some of the geothermal waters in Sumatera geothermal prospects have fluids which do not directly come from a reservoir, and encounter dilution with meteoric water or mixing process, or come from steam heated from brine. Another geothermal water of the manifestations in Sumatera Island is characterized by a brine that comes from deep liquid geothermal water with not much mixing proccess or dilution with meteoric water. Other analysis from this study that use geoindicator showed the association of some prospect with Great Sumateran Fault with some explanations about each water chemical characteristic.
|        Topic: Geochemistry||Paper Number: 14095|