Characteristics of Hydrochemical to Determine Reservoir Temperature Banda Baru Area, Amahai District, Central Maluku Regency, Maluku Province

The research area is located in Banda Baru Village, Amahai District, Central Maluku Regency, Maluku Province. This area has surface geothermal manifestations in the form of hot springs, steaming ground, sintered carbonate deposits (travertine), mud pools, and steam-heated water. The research objective was to determine the type, physical characteristics, and chemical characteristics as well as the estimated geothermal subsurface temperature in the research area. The research method used two methods, namely field observations and data processing including data analysis based on the chemical laboratory results of hot and cold spring samples. Plotting results of the Cl-SO4 -HCO3 ratio from hot springs (MAP BB-1, MAP BB-2, MAP BB-3, MAP BB-4, MAP BB-5) and cold springs (MAD BB-1, MAD BB-2) shows the type of bicarbonate of water in the peripheral water condition. Plotting the Cl-Li-B ratio of hot springs (MAP BB-1, MAP BB-2, MAP BB-3, MAP BB-4, MAP BB-5) and cold springs (MAD BB-1, MAD BB-2) is in the condition of absorption of high B/Cl steam. Plotting the Na-KMg ratio shows MAP BB-1, MAP BB-2, MAD BB-1, and MAD BB-2 as immature waters, while MAP BB-3, MAP BB-4, and MAP BB-5 in partial equilibrium conditions. The results of calculations using the thermal water geothermometer equation, it is estimated that the subsurface temperature of the research area ranges: 96°C124°C (Silica maximum steam loss equation), 95°C127