贵州织金地区金西剖面P-T界线附近地层研究

发布时间：2019-01-04 16:26

【摘要】：本文以贵州织金地区古生物学及沉积微相为研究对象,通过资料收集-地质调查-实验测试-理论分析,对研究区生物发育特征、碳酸盐岩微相等问题展开系统研究,结果表明:二叠纪末的生物大灭绝与三叠纪初生物复苏是显生宙生命发展史上最伟大的变革,见证了海洋生态系结构的巨大转变,同时也促使古生代生物群向现代生物群的转变。二叠纪末期生物大灭绝的型式是当前古生物学研究的热点问题之一。而通过详细的古生物特征的研究及沉积微相的研究能够识别古生物特征和沉积相历史的整体或局部环境。通过对华南上扬子中部的贵州织金地区古生物学的研究分析,试图在上扬子中部的斜坡相碳酸盐岩沉积区内恢复当时的生物组合与沉积模式组合。从古生物学和沉积岩石学的角度来佐证二叠-三叠纪之交所发生的生物与沉积事件。对研究区剖面中的颗粒与生屑组分进行了镜下观察,共识别出了10个门类的生物碎屑及泥状灰岩、生屑粒泥灰岩、生屑泥粒灰岩、生屑颗粒灰岩以及结晶灰岩5种岩石类型,识别出广海斜坡沉积环境,发育了中斜坡和外斜坡2种沉积亚相。并对贵州织金剖面二叠系-三叠系界线地层进行系统切片和研究,共鉴别出小有孔虫化石11属16种。这一丰富的有孔虫动物群,通过收集织金剖面的化石资料,也为研究二叠纪末的生物灭绝形式提供了新的依据。通过煤山剖面对比与分析,认为贵州织金地区的P-T界限定于A5层底部(第6层)与A4之上(第5-3层)之处。
[Abstract]:In this paper, paleontology and sedimentary microfacies in Zhijin area, Guizhou Province are taken as research objects. By means of data collection, geological survey, experimental test and theoretical analysis, the characteristics of biological development and the microequality of carbonate rocks in the study area are systematically studied. The results show that the great extinction of life at the end of Permian and the recovery of life at the beginning of Triassic are the greatest changes in the history of Phanerozoic life, which witnessed the great changes in the structure of marine ecosystem. At the same time, it also promoted the transformation of Paleozoic biota to modern biota. The extinction pattern of late Permian organisms is one of the hot issues in paleontology. Through detailed study of paleontological characteristics and sedimentary microfacies, paleontological characteristics and the whole or local environment of sedimentary facies history can be identified. Based on the paleontology of the Zhijin area in the middle of South China, the authors try to restore the assemblage of the biological assemblage and the sedimentary model in the carbonate sedimentary area of the slope facies in the central part of the Upper Yangtze River. From the perspective of paleontology and sedimentary petrology, the biological and sedimentary events occurred at the intersection of Permian and Triassic are proved. The microscopic observation of grain and debris components in the section of the study area shows that there are 10 types of bioclastic and muddy limestone, 5 types of bioclastic and mudstone, bioclastic marl, bioclastic granular limestone and crystalline limestone. The sedimentary environment of Guanghai slope has been identified and two sedimentary subfacies have been developed on the middle slope and the outer slope. The Permian-Triassic boundary strata in Zhijin section of Guizhou Province were systematically sliced and studied. A total of 11 genera and 16 species of foraminiferal fossils were identified. This abundant foraminiferal fauna provides a new basis for the study of the late Permian bioextinction by collecting fossil data from the Zhijin section. Based on the correlation and analysis of the coal mountain section, it is concluded that the P-T boundary of the Zhijin area in Guizhou is located at the bottom of the A5 layer (the sixth layer) and above the A4 layer (the 5-3 layer).
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P535

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