CAJ | 학술논문

二叠纪末生物大灭绝后,在华南地区碳酸盐岩台地上普遍形成一套微生物岩.微生物岩所代表的是一种以蓝细菌和其他底栖生物为主体的独特的生态系.蓝细菌作为生产者是该生态系的基础,种类单调的小型腹足类和介形虫等广盐性多细胞生物和灾后残存的有孔虫则是该生态系中的主要消费者.根据所处的古地理位置不同,华南微生物岩的分布可分为3个主要地区,即上扬子地区、中下扬子地区及南盘江地区.上述3个地区微生物岩分别产出在生物礁顶、一般碳酸盐岩台地边缘和孤立碳酸盐岩台地环境,且不同地区微生物岩所在剖面的沉积序列也存在差异.根据不同地区微生物岩在宏观沉积构造和碳酸盐岩微相组合上的差异,可进一步划分为层纹状微生物岩、叠层石微生物岩、花斑状微生物岩、树枝状微生物岩及穹窿状微生物岩.不同微相类型的微生物岩在沉积水深、蓝细菌化石、底栖群落组合上仍存在差异,其中树枝状和穹窿状微生物岩沉积时所处水深最小,花斑状微生物岩和层纹状微生物岩沉积时所处水深可能相对较大.对不同地区微生物岩的研究为认识二叠纪末全球事件期间海洋环境的多样性和演化过程提供了重要的信息.
이첩기말생물대멸절후,재화남지구탄산염암태지상보편형성일투미생물암.미생물암소대표적시일충이람세균화기타저서생물위주체적독특적생태계.람세균작위생산자시해생태계적기출,충류단조적소형복족류화개형충등엄염성다세포생물화재후잔존적유공충칙시해생태계중적주요소비자.근거소처적고지리위치불동,화남미생물암적분포가분위3개주요지구,즉상양자지구、중하양자지구급남반강지구.상술3개지구미생물암분별산출재생물초정、일반탄산염암태지변연화고립탄산염암태지배경,차불동지구미생물암소재부면적침적서렬야존재차이.근거불동지구미생물암재굉관침적구조화탄산염암미상조합상적차이,가진일보화분위층문상미생물암、첩층석미생물암、화반상미생물암、수지상미생물암급궁륭상미생물암.불동미상류형적미생물암재침적수심、람세균화석、저서군락조합상잉존재차이,기중수지상화궁륭상미생물암침적시소처수심최소,화반상미생물암화층문상미생물암침적시소처수심가능상대교대.대불동지구미생물암적연구위인식이첩기말전구사건기간해양배경적다양성화연화과정제공료중요적신식.
Microbialites were widely distributed on the carbonate platform in South China after the end-Permian mass extinction. Microbialites represent a particular ecosystem, composing of cyanobacteria and other benthonic organisms. Cyanobacteria played an important role as the producers in the ecosystem,while the euryhalinous and benthic faunas were the main customers, including low-diversity microgastropods, ostracods, and disaster foraminifers. Based on the different palaeogeographic location, microbialites in South China can be divided into three districts: the Upper Yangtze platform, the Middle and Lower Yangtze platform and the Nanpanjiang Basin. Microbialites in the above areas were produced on the top of reef facies, carbonate platform and isolated carbonate platforms respectively. Section sequences where microbialites were developed are different from place to place. Microbialites can be subdivided into different types based on macro sedimentary fabrics and carbonate microfacies, including the laminated microbialite, stromatolite, clotted microbialite, digitate and domed microbialites. Different type8 of microbialites were formed in different water depths, containing different assemblages of cyanobacteria and benthic animal fauna. Our research indicates that the digitate or domed microbialites should have been deposited in the most shallow water environment and the laminated or clotted microbialite probably in relatively deep water conditions. Study of the sedimentary structures and carbonate microfacies of microbialites in different areas in South China will provide important information about the diversity and evolution of the oceamc environment during the end-Permian global event.