贵州青岩地区早-中三叠世生物地层  

Lower-Middle Triassic Strata in Qingyan, Guizhou Province, South China

作　　者：陈晶[1] 童金南[1] 牛志军[2] 周士钦[1] 宋海军[1] 易飞[1] 

机构地区：[1]中国地质大学生物地质与环境地质教育部重点实验室,湖北武汉430074 [2]宜昌地质矿产研究所,湖北宜昌443003

出　　处：《地球科学（中国地质大学学报）》2010年第1期51-61,共11页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目(Nos.40830212;40621002);国家"973"科学研究计划(No.2006CB80640);中石化"十一五"前瞻性研究项目(No.G0800-06-ZS-319)

摘　　要：贵州青岩地区下-中三叠统发育齐全,化石丰富,尤其是中三叠世"青岩动物群",具有生物辐射性质.为了研究二叠纪末生物大灭绝事件后的生物复苏及辐射过程,对该区下、中三叠统剖面进行了实测,并从沉积学、古生物学上进行了系统研究.识别出5个牙形石带:Neospathodus dieneri带、Neospathodus waageni带、Neospathodus pingdings hanensis带、Neos-pathodus homeri带、Chiosella timorensis带,建立2个有孔虫组合和6个双壳类组合.并根据牙形石化石初步确定出印度阶与奥伦尼克阶及奥伦尼克阶与安尼阶的界线.多门类化石的分布和生态组合结构表明,大灭绝后的复苏-辐射第一幕发生于安尼期早期,安尼期中期雷打坡页岩段的化石组合具有典型辐射后期的生态繁荣景象.古环境研究表明,本区从三叠纪初到中三叠世安尼期沉积水体总体上震荡式变浅,表现为盆地-陆棚-台缘斜坡-台地-盆地-台缘斜坡-陆棚的演变过程.The Lower-Middle Triassic strata in Qingyan, Guizhou are well exposed and have abundant fossils. In particular, the Qingyan fauna in Middle Triassic shows biota radiation. The stratigraphical sequence has been studied extensively for a better understanding of the course and pattern of the biotic recovery and radiation following the End-Permian mass extinction. Five co- nodont zones, including Neospathodus dieneri zone, Neospathodus waageni zone, Neospathodus pingdingshanensis zone, Neospathodus homeri zone, and Chiosella timorensis zone, 2 foraminifer assemblages and 6 bivalve assemblages are recognized. The boudaries of Induan-Olenekian and Olenekian-Anisian have been defined by the conodonts. Various fossils and their ecologic assemblages indicate that the first episode of recovery-radiation after the End Permian extinction happened in the early Ainisian, and the fossil assemblages in Leidapo Member （Middle Anisian） reveal a typical prosperous biotic ecosystem after radiation. The brachiopod assemblages, Madoia sp. assemblage and Rhaetina angustaeformis assemblage, from the Middle Anisian Qingyan Formation represent the first radiation of brachiopod faunas from the recovery. In addition, the sedimentary evidence indicates two up-shallowing cycles of paleoenvironmental setting, basin-slope-platform-basin-slope-shelf.

关 键 词：下-中三叠统 生物地层 生物复苏与辐射 贵州青岩. 

分 类 号：P534.51[天文地球—古生物学与地层学]