T The State of Indonesia has a large geothermal potential which is based on thegeographical location and geological conditions of Indonesia, which is crossed byfault zones and there are many volcanoes, as a result of which the State of Indonesiais traversed by the Ring of Fire route. This research is intended to understand thegeochemical characteristics of the research area. The location of the research area isin the Arjosari area and its surroundings, Arjosari District, Pacitan Regency, EastJava Province. Regionally, the research area consists of arjosari formationscomposed of sedimentary rocks in the form of conglomerates, sandstones, siltstones,limestones, sandy marl, pumice sandstones, volcanic breccia inserts, lava and tuff,and the Mandalika Formation composed of alternating volcanic breccias, lava, tuff,inserts tuffaceous sandstone, siltstone, and claystone. Geothermal manifestationswith the type of manifestation in the form of hot springs, warm springs, and coldsprings, with the type of acid sulphate waters, with geoindicators that tend to pointtowards the east, the isotopic meteorik line.