Genesis of Sr Isotopes in Groundwater of Hebei Plain

To analyze the genesis of Sr isotopes in groundwater of Hebei plain, time-accumulative effect of 87Sr/86Sr ratio was studied. It is shown that 87Sr/86Sr ratio increases with the increasing age and depth of groundwater and has a positive correlation to 4Heece and a negative correlation to δ18O and δD. The groundwater is divided into three groups to discuss the relation between 87Sr/86Sr ratio and Sr2+ content: moderate Sr2+ content and higher 87Sr/86Sr ratio (water I); lower Sr2+ content and higher 87Sr/86Sr ratio (water II); and higher Sr2+ content and lower 87Sr/86Sr ratio (water III), that is hot water. On the basis of integrated analysis, it was considered that the radiogenic Sr in the Quaternary groundwater (Q4-Q1) originates from weathering of silicate rich in Na and Rb, mainly from plagioclase; the radiogenic Sr of hot water in Huanghua port is attributed to carbonate dissolution, with lower 87Sr/86Sr ratio and higher Sr/Na ratio; the recharge area is laterally recharged by the groundwater flowing through igneous and metamorphic rocks, with moderate 87Sr/86Sr ratio. However, the formation mechanism of Sr isotopes in Tertiary groundwater needs further studies.