歧口凹陷奥陶系潜山加里东中晚期均衡岩溶作用

均衡岩溶是裸露岩溶的一种,发育于加里东中晚期.歧口凹陷位于黄骅坳陷中北部,晚奥陶世华北地台受加里东运动的影响而整体抬升暴露,区域内为准平原化地貌；奥陶系地层展布相对平缓,岩性是以石灰岩和白云岩为主的碳酸盐岩,偶见少量蒸发岩;奥陶纪时期华北地台处在赤道附近位置,气候湿润而温暖,大气中CO2浓度很高,富含CO2的强酸性岩溶水,为均衡岩溶的发育提供条件.

On Balanced Karst of Middle and Late Caledonian Movement in Limestone of Buried Hill of Qikou Sag

Balanced karst,which belongs to bare karst develops during middle and Late Caledonian below the paleo-weathering crust,and this new karstification can be learned through various geologic proof.Qikou sag locates in central and nouthern Huanghua depression.In late Ordovician,North China platform is uplifted to expose as a result of Caledonian movement,and the geomorphy in the area is peneplain.Ordovician stratigraphic distribution is relatively gentle inclined with its lithology carbonate rock consist of limestone,dolomite and rare evaporite.Ordovician North China platform is around the equator,where the climate is moist yet hot,and the concentration of CO2 stays high which results in strong acidity karst water,and these provide the conditions for banalanced karst and influence its development.