Hydrochemical Characteristics And Water-rock Reaction Of Hot Spring In Metamorphic Rock Area Of Southeast Guizhou

The water rock reaction is the chemical reaction between the fluid and the rock,and the energy,mass and isotopes of the fluid and the surrounding rocks are exchanged.The ions in geothermal water are mainly from the reaction of water rocks.The characteristics of ionic components can reflect the lithological characteristics of aquifers and the degree of water rock reaction to a certain extent.For a long time,people have gone deep into the genesis of hot spring,the source of hot spring water and the temperature of heat storage,and have achieved some corresponding results.However,the research on the water and rock interaction process of hot springs is relatively lacking.Therefore,based on many scholars' research,this paper studies the hydrochemical characteristics and hydrochemical characteristics of hot springs in Metamorphic Rock Area of Southeast Guizhou.This article selects four hot springs and surrounding rocks from Jianhe,Huangping,Leishan and Taijiang in the metamorphic rock areas of southeast Guizhou as the research object,and uses the methods of field observation,rock and mineral appraisal,determination of the contents of various chemical components of water,and geochemical analysis.The research ideas in fields such as mineralogy,petrology,geochemistry,and hydrogeology have been used to explore comprehensively from multiple disciplines and perspectives.Study on Chemical Characteristics of Hot Spring Water and Reaction of Water and Rock in Metamorphic Rock Area in Southeast Guizhou.The studying gets several conclusions as follows:The main exposed stratum in the study area is the Xiajiang Group of the Qingbaikou Formation,a set of shallow metamorphic rock clastic rocks.The hot spring exposed strata mainly consist of the Qingshuijiang Formation,characterized by containing more tuffaceous matter,mainly Surplus sediment tuff,altered sandstone,Palimpsest siltstone and slate,etc.The main rock minerals are quartz,feldspar,rock debris,and a small amount of mica and pyrite.All the hot springs in the study area are fractured?fracture?hot springs,which are mainly controlled by fault structures,and the recharge is mainly atmospheric precipitation.The temperature is 27.5⁴2.8?,and it is a medium-low temperature hot spring;the p H value is 7.8⁸.7,belonging to weak alkalinity;the main ions are Na+ and HCO3-,and the ion concentration range is 58.9³10mg.L-1 and 131⁷03mg.L-1,It's a typical HCO₃^-Na type of water.By analyzing the geochemical characteristics of trace elements and REE in rock samples and hot spring water as well as the sources of main ions in hot springs,it is revealed that the study area has a certain role of water and rock.Most of the ions in the hot spring water of the study area originate from the reaction of water rocks.Trace elements in water basically inherit the Characteristics of trace elements in rocks.The rare earth element in water is the rare earth element in the rock that enters the body of water,but the hot water Eu showed an obvious positive anomaly,The rare-earth element in the water body inherits the rare earth element characteristics of plagioclase during the process of water-rock reaction,which showed Eu positive anomaly.Therefore,the composition of rare earth elements is mainly restricted by the reaction of albite and water in the Qingshuijiang Formation.Na+ is the reaction of sodium feldspar in rock and rich in CO2 water;The SO42-and hydrophilic elements Cu,Pb,Zn,As,Sb and so on are mainly derived from the oxidation and dissolution of pyrite in the rock.Through the water chemical characteristics of hot spring water in the study area,and the correlation between the rock and water composition change of the trace elements analysis,most of the ions in the study area from water-rock reaction,speculated that mainly occurs in the study area of water-rock reaction is: sodium feldspar reaction with rich CO2 water,plagioclase and reaction between water and pyrite under the condition of oxidation reaction with hot water,etc.