古交矿区奥灰岩溶发育特征及主控因素研究

Study on Development Features and Major Control Factors of Ordovician Limestone Karst in Gujiao Mining Area

为查明古交矿区奥灰岩溶发育特征及控制因素,通过对野外地质观查、水文地质钻孔资料对比及室内试验分析得出:峰峰组顶底分别发育一段相对隔水层,中间为第1岩溶含水层,上马家沟组底部为相对隔水层,上部分别为第2、3岩溶含水层;奥灰顶部充填型相对隔水层受古构造运动控制,奥灰强弱相间的岩溶现象受其岩性韵律组合的控制,泥灰岩段成为裂隙岩溶含水层段是因为石膏层的盐丘作用产生了似层状的膏溶角砾岩带、压碎岩带和裂隙带。研究认为古交矿区峰峰组顶部近30m厚的充填型隔水层及下段泥灰岩石膏层可作为隔水关键层。

In order to investigate the development features and control factors of the Ordovician limestone karst in Gujiao Mining Area, a comparison on the field geological survey and the hydrological drilling information and the indoor test analysis were conducted.The results showed that a section relative water isolation layer with a first karst aquifer in the middle was individually developed in the roof and floor of the Fengfeng Group.The floor section of Shangmajiagou Group was a relative water isolation layer and above the water isolation layer, there were second and third karst aquifers.The backfill type relative water isolation layer at the top of the Ordovician limestone was controlled by the movement of the paleostrueture.The karst phenomenon between the strong and weak phases of the Ordovician limestone was controlled by the lithology rhythm combination.The marlite section became water bearing layer section of the crack karst, due to the salt dome role of the gypsum formation caused a layer like gypsum karst conglomerate zone, broken rock zone and crack zone.The study held that 30 m thick backfill type water isolation layer at the top of Fengfeng Group and marlite gypsum formation at the bottom of the Fengfeng Group could be the water isolation key layer.