Strontium isotope systematics of groundwater in the Hebei Plain, Northern China

摘要

Groundwater is the most important source of water supply for Hebei Plain, and the groundwater system can be divided into 7 aquifers. In this study, 87 Sr/86Sr ratios and major ion hydrochemistry of groundwater were analyzed to understand strontium isotope systematics of groundwater in Hebei Plain. Based on integrated analysis, we suggest that the radiogenic Sr in groundwater sampled from Quaternary sediments (Q4-Q1) comes from the weathering of silicate minerals rich in Na and Rb. The 87Sr/86Sr ratios show a systematic increase with increasing age and depth of groundwater, reflecting the accumulative effect of water-rock interaction with time. Geothermal waters associated with Ordovician limestones have high Sr content and low 87Sr/86Sr ratios that mirror the values in the host rocks. The Sr isotope systematics of geothermal waters in Tertiary sediments require further study.