WANG Jiangsi, OUYANG Zhengping, XU Zidong, WANG Wenmei, YANG Yongchang

(Hainan Investigation Institute of Hydrogeology and Engineering Geology，Hainan Haikou 571100，China）

Abstract: This paper takes the thermal water well as an object, which is distributes in Fubao geothermal field, Ledong County, Hainan Province, China and uses hydrogeochemical information method and environmental isotope technology to analyze the formation mechanism of geothermal water. Results show that the area is characterized with high metasilicate and low salinity, and type of hydration is HCO3-Ca. With characteristics of hydrogen isotope and oxygen isotope and trilinear charts of Cl-SO4-HCO3 and Na-K-Mg, it is clear that the area’s geothermal water mainly comes from atmospheric precipitation, which is less affected by the earth's crust deep geothermal water. Based on age determination results of 3H isotope and 14C isotope in the geothermal water, it could be concluded that there isn't large scale regional geothermal water runoff model, and there exists normal temperature water in the process of exposure.

Key words: geothermal water；hydrogeochemical information；environmental isotope

EARTH AND ENVIRONMENT Vol.46, No.1, Tot No.321, 2018, Page 7-14