太行山隆起中段东麓良河西村大桥北剖面张夏—崮山组碳酸盐岩工厂沉积演化研究OACHSSCD

Taking the Cambrian Zhangxia-Gushan Formations in the section north of Lianghexicun Bridge at the eastern foot of the middle segment of the Taihang Uplift as the research object,this paper combines the regional geological background of the study area,field measured profiles and indoor microscopic identification to conduct an in-depth analysis of the types and evolutionary laws of carbonate factories in this region.Located in the central part of the North China Craton,this area has well-exposed Cambrian-Ordovician carbonate rocks affected by multiple phases of tectonic movements.The Zhangxia Formation is dominated by thick-bedded oolitic limestone and stromatolitic limestone,which were formed in high-energy platform margin shoals and restricted platform environments dominated by organisms and microorganisms.The Gushan Formation is composed of interbedded purplish-red calcirudite,micrite and calcareous shale,corresponding to oxidizing environments and low-energy fore-slope-restricted platform environments.Vertically,the carbonate factories generally exhibit an evolutionary sequence of high-energy shoal factories-storm-disturbed factories-oxidizing-environment calcirudite factories-low-energy fore-slope factories-restricted platform factories.This sequence completely records the late Middle Cambrian regression event of the North China Platform,providing a typical case for the study of carbonate sedimentary models and paleoenvironmental evolution in North China.