华北型煤田奥灰水水化学和同位素特征研究——以兖州煤田为例

为了更好地理解研究区的水循环,并为突水水源判别打下基础,很有必要研究奥陶系地下水水化学和同位素特征。奥陶系灰岩水(简称奥灰水)主要的水化学类型为Ca-MgSO4,主要阳离子为SO2-4和Ca2+。Ca2+和SO2-4与TDS都有很好的线性相关性,R2值分别为0.978和0.996,而且随TDS的增加,Ca2+和SO2-4浓度增长速度也是最快的。奥灰水中方解石和白云石处于过饱和状态,但是石膏和方解石未饱和。Cl-和TDS的分布与地下水流场有较好的一致性。研究区代表性的雨水线为:δD=7.80δ18O+6.28,分析结果认为奥灰水不是当地降水的补给。

Study on the hydrogeochemistry and isotope characteristics of Ordovician groundwater in typical coalfield of North China--taking Yanzhou as an example

In order to get a clear understanding of water circulation and lay the foundation for discriminat - ing the water source of mine water inrush, it＇ s necessary to study the hydrogeochemistry and isotope charac - ter- istics of the Ordovician limestone groundwater in study area. The main water type of Ordovician limestone groundwater is Ca - Mg - SO4. The main ions are SO42- and Ca2＋. There was very good linear correlation be - tween the concentration of Ca2 ＋, SO42- and TDS （ R2 = 0. 978, R2 SO4 = 0. 996）, and the increase velocity of the Ca2＋ and SO24- concentration was the largest. Calcite and dolomite were oversaturated, but gypsum and anhy - drite were unsaturated. The distribution of CI- and TDS was analogous to groundwater flow field. The repre - sentative meteoric water line of the study area isδD = 7.80δ 18 O ＋ 6.28, and Ordovician limestone groundwa -ter was not recharged from local precipitation.