Microfacies and paleoenvironment of microbialites of the Cambrian(Stage 4)Qingxudong Formation in the Huayuan area,northwestern Hunan Province,southern China  

作　　者：Zhong-Tang Su De-Min Zhang Jie Tang Pei-Jie Sun Zhen-Feng Luo Hui Ma 

机构地区：[1]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,Sichuan Province,China [2]Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resource,Chengdu University of Technology,Chengdu 610059,Sichuan Province,China [3]Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,Sichuan Province,China [4]Sinopec Petroleum Exploration and Production Research Instutite,Beijing 100083,China

出　　处：《Journal of Palaeogeography》2023年第4期587-602,共16页古地理学报（英文版）

基　　金：National Natural Science Foundation of China(NSFC,No.41972104)。

摘　　要：After the extinction of Archaeocyatha(sponges),microbial bioherms were well developed in the lower Cambrian of the Yangtze cratonic basin,especially in the Qingxudong Formation(Cambrian(Stage 4))of the Huayuan area,northwestern Hunan Province,southern China.Herein,four sections from this area were chosen for investigating and analyzing their microfacies and depositional environment.Twelve microfacies types were recognized through petrographic analysis of textural attributes and calcimicrobes(including Epiphyton,Renalcis,Girvanella and Kenella),respectively as:laminated calcareous mudstone(MF1),algal wackestone(MF2),intraclastic grainstone(MF3),algal intrasparrudite(MF4),oolitic algal intrasparrudite(MF5),sparry oolitic grainstone(MF6),Epiphyton framestone(MF7),Renalcis bafflestone(MF8),Kenella bafflestone(MF9),Girvanella boundstone(MF10),thrombolitic boundstone(MF11),and dolomite(MF12).These microfacies represent four major depositional environments:carbonate ramp,carbonate platform,slope and tidal flat.Calcimicrobes played an important role in the transition from carbonate ramp to platform,while the evolution from ramp to tidal flat must be ascribed to sea-level fall during the Cambrian Age 4.

关 键 词：MICROFACIES MICROBIALITE Carbonates EPIPHYTON CAMBRIAN Yangtze craton Sea level 

分 类 号：P618.13[天文地球—矿床学]