Study of Water-rock Interaction with Hydrochemical and Isotopic Datum in Laizhou Bay

Water-rock interaction of the groundwater in aquifer system has been analyzed and inferred with hydrochemical and isotopic datum in Laizhou Bay, eastern China. 32 samples of groundwater from three boreholes (96-5#, 96-6#, 112- 1#), couples of seawater, saline water, fresh water, surface water and rainfall are obtained in study area for hydrochemical and isotopic analyses. The origin of groundwater is generally concluded by stable isotope (δ 18 O and δD) and the analytic results of Na + , Ca 2+ , Mg 2+ , Cl - , SO 4 2- , HCO 3 - changing with depth, combined with total dissolved solids (TDS), electrical conductivity (EC), can be apparently proofs for serious water-rock interaction. The conclusion reveals that the origin of 96-5#, 112-1# is most likely saline water different from that the groundwater of 96-6# which is possible originated from fresh water, surface water or mixing of both. Compared the ion content of same borehole at different depth and different boreholes with same depth, the optimal area for building main well and mining area is determined eventually is around 96-5#.