逆冲推覆体下煤系砂岩和太灰含水层水化学特征

Water Chemical Characteristics of Coal Bearing Aquifer and the Taiyuan Formation Limestone Aquifer Under Thrust Nappe

为研究阜凤逆冲推覆体下煤系砂岩和太灰含水层水化学特征,对淮南新集矿区(新集一矿、二矿和三矿)进行水样采集、测试及分析,采用Piper三线图、相关性分析及离子比例系数讨论水化学特征及其成因。结果表明:(1)煤系砂岩水和太灰水,阳离子中Na^+占比重最大,来源于岩盐溶解、阳离子交替吸附以及钠长石的溶解,Ca^(2+)次之;阴离子以Cl^-为主,主要来源于岩盐的溶解,HCO_3^-次之,HCO_3^-和Ca^(2+)主要来源于碳酸盐的溶解。煤系砂岩水水化学类型为Cl-Na、Cl·HCO_3-Na型;太灰水的水化学类型为Cl·HCO_3-Na、Cl-Na、Cl·HCO_3-Na·Ca型。(2)受推覆体影响,两个含水层的水动力条件较差;就三个矿井而言,处于推覆体前缘、离推覆体较远的新集三矿水动力条件较一矿和二矿好。

In order to explore the hydro-chemical characteristics of groundwater from the coal bearing aquifer and the Taiyuan formation limestone aquifer under Fufeng Thrust Nappe,water samples were collected, tested and analyzed in Huainan Xinji mining area (Xinji No.1 Mine, Xinji No.2 Mine and Xinji No.3 Mine), using Piper's three-line diagrams, correlation analysis and ionic proportional coefficients discuss water chemistry characteristics and its causes. The results show that:(1) In the groundwater samples from coal bearing aquifer and the Taiyuan formation limestone aquifer, Na +accounts for the largest proportion of cations, which was derived from rock salt dissolution, cation alternating adsorption and dissolution of dissolution of sodium feldspar, followed by Ca ^2+;anions were mainly Cl^-, mainly derived from the dissolution of rock salt. and HCO3^- was in the third place. HCO - 3 and Ca ^2+ were mainly derived from the dissolution of carbonates. The former were Cl-Na and Cl·HCO 3-Na type whereas the latter were Cl-Na、Cl·HCO 3-Na and Cl·HCO 3-Na·Ca type.(2) Under the influence of the nappe, the hydrodynamic conditions of groundwater from these two aquifers were poor. For the three mines, the hydrodynamic conditions of the Xinji No.3 Mine that was at the leading edge of the nappe and farther away from the nappe, was better than that of the Xinji No.1 Mine and Xinji No.2 Mine.