Abstract:We analyze the constant chemical composition and hydrogen, oxygen isotope and tritium activity data of observation well water, atmospheric precipitation, cold spring water, geothermal hot spring water and surface water samples in the Lushan area around Jiujiang. We show that the groundwater in the Lushan area is mainly divided into two hydrogeological units in the northwest and southeast.The hydration type represented by Jiujiangtai No.2 well water and Donglin Temple is HCO3-Ca type on the northwest side, while the hydration type represented by geothermal spring well water and Guanyinqiao spring is HCO3-Na type on the southeast side; the ion component mainly comes from weathering of crust rocks. Hydrogen and oxygen isotopes indicate that the groundwater in the Lushan area of Jiujiang belongs to the cause of precipitation, and some confined fractured well springs have deep circulation characteristics.Estimating the chloride ion indicates that the direct recharge rate of atmospheric precipitation is about 4.5%-33.27%. The formation of fissures and pressured artesian wells by infiltration recharge under atmospheric precipitation is the main cause of groundwater in Lushan area, a part of which is the formation of geothermal hot spring water through long-term and deep circulation of precipitation. The characteristics of Jiujiangtai No.2 well has both shallow surface water and circulation water, suggesting aquifers of two different recharge sources rise to the shallow bottom through different circulation paths, contributing to carrying part of the information of deep tectonic activity, is helpful to obtain seismic precursor anomaly information.
BAO Zhicheng,ZHA Xiaohui,ZHAO Ying et al. Hydrogeochemical Characteristics and Genesis of Groundwater in Lushan Area of Jiujiang[J]. jgg, 2021, 41(5): 471-577.