Regional geothermal exploration in Dongpu geothermal field of central Taiwan

Abstract

Dongpu geothermal potential field is located in the shale belt of the Hsuehshan Range in Nantou County, central Taiwan. The key exploration area will cover an area of approximately 53 square kilometers, including the Dongpu Hot Spring and the Lele Hot Spring. The major interest of geothermal exploration is to understand the location of heat source and geological information. Geothermal fluids included thermal water and gas, which emitted from geothermal reservoir through faults and/or fissures. In general, geothermal fluids formed hot springs and fumarolic gas (or bubbling gas) at the Earth’s surface, and in which the information of geothermal reservoir was preserved. Therefore, based on chemical and isotopic composition of fluids can provide the information of the origin and evaluation. In this study, we conducted fluid geochemical survey at geothermal fluids outcrops in the region of Dongpu Hot Spring and the Lele Hot Spring. We measured the fluid composition and also helium isotope composition of the sampled hot spring water and bubbling gas. Together with previous studies, we discussed the geochemical characterization, which may provide further insights on geothermal resource assessment.