Hydrochemical characteristics and genesis of geothermal water in the area of Dong River in Yingshan,eastern Hubei
Dong River in Yingshan County in eastern Hubei Province is rich in geothermal resources,and has good geological heat generation conditions and resource development and utilization prospects.Taking Dong River as the research area,this paper explored the evolution characteristics of geothermal water by the Piper three-line diagram,saturation index calculation,ion ratio,and reaction path simulation method,identified sources of geothermal water using the hydrogen and oxygen isotopes,and established a concep-tual model of geothermal water in the study area based on more comprehensive research,which provides a scientific basis for further exploitation and utilization of geothermal resources in Yingshan Dong River area in eastern Hubei Province.The research shows that the chemical type of groundwater in the study area is mainly SO4-Na type,followed by HCO3·SO4-Na type.The hydrochemical evolution process of thermal fields in various regions is similar,and the main water-rock interactions are the dissolution of gypsum and feldspar minerals and cation exchange.The conceptual model of the origin of groundwater in the study area is as follows:atmospheric precipitation over 800 m in the north and northeast of the study area flows along the NNE or NE faults in the area,and the dissolution of gypsum,feldspar and other minerals and cation ex-change occur under deep cycle heating conditions.As a result,geothermal water rises along faults and fis-sures in the central and southern low places of the study area(Caopandi,Yangliuwan,and surrounding areas of Wenquan Town),forming a series of geothermal systems with similar evolution patterns and rela-tively spatial independence.The research results can provide scientific basis for the further development and utilization of geothermal resources in the study area.