Calcimicrobialite after end-Permian mass extinction in South China and its palaeoenvironmental significance  

作　　者：WANGYongbiao TONGJinnan WANGJiasheng ZHOUXiugao 

机构地区：[1]FacultyofEarthSciences,ChinaUniversityofGeosciences,Wuhan430074,China

出　　处：《Chinese Science Bulletin》2005年第7期665-671,共7页

基　　金：the National Natural Science Foundation of China(Grant Nos.40232025 and 40325004).

摘　　要：Calcimicrobialites, which could be correlated to the layer 27 in Meishan section according to the Hindeodus parvus, occur abruptly on the end-Permian mass extinction boundary in South China. Microbialites mainly distribute on the top of reef facies or shallow carbonate platforms, thin- ning into deep facies. All the microbialites discovered are composed of micrite and coarse crystal digitate carbonate or patch carbonate. Microfossils usually dominate in the micro- bialites, and small gastropods, bivalves and ostracodes can also be found. This fossil assemblage represents a simple but particular remanent biota after the end-Permian mass ex- tinction on the top of reefs or shallow carbonate platforms. Abrupt occurrence of microbialites above the mass extinction boundary is the ecological response to the end-Permian global event in reef or shallow carbonate facies. Many studies have been done on the Permian-Triassic boundary and event in deep water facies sections or middle to lower shelf facies sections. However, the calcimicrobialites in South China are mainly located above reef facies or shallow carbonate plat- form facies. It will surely be helpful for people to know more about the different responses in different depths of ancient marine environment during the transition between Permian and Triassic by the study of petrology, palaeontology and palaeoecology of the calcimicrobialites.Calcimicrobialites, which could be correlated to the layer 27 in Meishansection according to the Hindeodus parvus, occur abruptly on the end-Permian mass extinctionboundary in South China. Microbialites mainly distribute on the top of reef facies or shallowcarbonate platforms, thinning into deep facies. All the microbialites discovered are composed ofmicrite and coarse crystal digitate carbonate or patch carbonate. Microfossils usually dominate inthe microbialites, and small gastropods, bivalves and ostracodes can also be found. This fossilassemblage represents a simple but particular remanent biota after the end-Permian mass extinctionon the top of reefs or shallow carbonate platforms. Abrupt occurrence of microbialites above themass extinction boundary is the ecological response to the end-Permian global event in reef orshallow carbonate facies. Many studies have been done on the Permian-Triassic boundary and event indeep water fades sections or middle to lower shelf facies sections. However, the calcimicrobialitesin South China are mainly located above reef facies or shallow carbonate platform facies. It willsurely be helpful for people to know more about the different responses in different depths ofancient marine environment during the transition between Permian and Triassic by the study ofpetrology, palaeontology and palaeoecology of the calcimicrobialites.

关 键 词：二叠纪 中国 微晶灰岩 晶体 地质意义 

分 类 号：P58[天文地球—岩石学] P534.46[天文地球—地质学]