渭北煤田主要充水含水层氢氧同位素特征及指示意义

Hydrogen and Oxygen Isotope Characteristics and Indicative Significance of Main Water-filled Aquifers in Weibei Coalfield

为探查矿区含水层补径排特征,开展了含水层氢氧同位素化学研究。以渭北煤田为研究对象,对研究区4个矿区的3个主要充水含水层和采空区,采集并测试了31组稳定氢氧同位素样品和7组放射性氢氧同位素样品。结合矿区水文地质资料与矿井涌水特征,综合分析了研究区充水含水层同位素地球化学特征及其指示意义。研究结果表明:研究区奥陶系灰岩含水层浅埋和深埋范围普遍与大气降水有联系。董家河煤矿相近太原组灰岩含水层和奥陶系灰岩含水层水力联系密切。研究区奥陶系径流方向整体为自西向东流动。研究区太原组灰岩含水层存在氧漂移现象,说明该含水层在煤炭开采扰动下,水岩相互作用密切。

In order to explore the recharge,runoff and discharge characteristics of the aquifer in the mining area,the hydrogen and oxygen isotope chemistry of the aquifer was studied.Taking Weibei coalfield as the research object,31 groups of stable hydrogen and oxygen isotope samples and 7 groups of radioactive hydrogen and oxygen isotope samples were collected and tested in 3 main water-filled aquifers and goafs in 4 mining areas in the study area.Based on the hydrogeological data of the mining area and the characteristics of mine water inflow,the isotopic geochemical characteristics of the waterfilled aquifer in the study area and its indicative significance are comprehensively analyzed.The results show that the shallow and deep burial range of Ordovician limestone aquifer in the study area is generally related to atmospheric precipitation.Dongjiahe coal mine is close to Taiyuan formation limestone aquifer and Ordovician limestone aquifer.The Ordovician runoff in the study area flows from west to east as a whole.There is oxygen drift phenomenon in the limestone aquifer of Taiyuan formation in the study area,which indicates that the water-rock interaction is close under the disturbance of coal mining.