蒙陕接壤区深埋型煤层顶板水文地质及水文地球化学特征

Hydrogeological and Hydrogeochemical Characteristics of Deep Buried Coal Seam Roof in Shaanxi and Inner Mongolia Contiguous Area

为了弄清蒙陕接壤区深埋型煤层顶板水文地质及水文地球化学特征,利用水文地球化学数据开展了综合研究,结果表明:白垩系志丹群与第四系之间水力联系密切,矿化度较低,属于HCO3-Ca型水,与志丹群底板标高没有相关性。安定组可有效地阻隔上部含水层水对直罗组的补给;大部分矿井主采煤层到安定组顶板距离较大(>250 m),导水断裂带不会波及志丹群含水。主采煤层顶板含水层水中矿化度与地层标高呈负相关关系,大部分水样属于深部滞留型的SO_4-Na型水;但榆横北区的几个矿,普遍属于SO_4-Na·Ca型水,Cl/HCO3值也偏小,表明榆横北区上下含水层联系相对较好。

In order to make clear the hydrogeological and hydrogeochemical characteristics of deep buried coal seam roof in Shaanxi and Inner Mongolia contiguous area,hydrogeochemical data are used to carry out a comprehensive research. The results showed that Cretaceous Zhidan group has close hydraulic connection with Quaternary aquifer and the water chemical characteristic is HCO3-Ca type water with low degree of mineralization. The hydrogeochemical characteristics were not related with floor elevation of Zhidan group aquifer. Anding group can effectively cut off the upper aquifer water supply into Zhiluo formation aquifer and Yanan formation aquifer. The distance from main mining coal seam to Anding formation roof was larger（〉 250 m）,and the height of diversion fissure zone could not reach Zhidan group aquifer. There was a negative correlation between total dissolved solids（ TDS） and stratum elevation in the roof aquifer of main mining coal seam. The water chemical characteristic was SO_4-Na type water in most coal mines. But the water chemical characteristic was SO_4-Na·Ca type water in Yubei Mining Area,and the value of Cl/HCO3 was small. There was better hydraulic connection in Yubei Mining Area than other areas.