Composition and Construction of High-and Low-Energy Ooid Shoals and Their Relationships with Environmental Changes: A Case Study from the Cambrian Zhangxia Formation in the Ordos Basin, North China  

作　　者：Zhen Wang Yiming Gong 

机构地区：[1]State Key Laboratory of Biogeology and Environmental Geology,School of Earth Sciences,China University of Geosciences,Wuhan,430074,China

出　　处：《Journal of Earth Science》2023年第1期156-172,共17页地球科学学刊（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos. 42272014, 41290260 and 41872034)。

摘　　要：On the basis of systematic study of sedimentary facies, microfacies and geochemistry of measured strata sections and wells, the ooid shoals of the Cambrian Miaolingian Zhangxia Formation in the southern Ordos Basin are composed of both high-and low-energy ooid shoals. The characteristics of the high-energy shoals are sparry cementation, with moderate to well sorting, large grain size, high ooid content and low micrite, weak micritization, and well-preserved internal textures of the ooids. Macroscopically, the high-energy ooid shoals display a thick-bedded aggradational stacking pattern in upward coarsening and thickening sequences. The low-energy ooid shoals are mainly made up of micritic cementation, with moderate to poor sorting, relatively small grain size, lower ooid content and higher micrite, strong micritization, and poorly-preserved internal textures of the ooids. Macroscopically, the low-energy ooid shoals show a thin-bedded, interbedded stacking pattern in upward fining and thinning sequences. The sedimentological evidence and carbon isotope data show that the differences of internal fabric and sedimentary evolution of both high-and low-energy ooid shoals are closely related to the sea-level change.

关 键 词：CAMBRIAN sedimentary model North China ooid shoals Ordos Basin Zhangxia Formation 

分 类 号：P53[天文地球—古生物学与地层学]