关于贵州青岩地区中三叠世青岩组上部的菊石组合及其时代的再研究--雷打坡化石组合的准确生物地层对比及年龄(英文)  

PRECISE BIOSTRATIGRAPHICAL CORRELATION AND AGE OF THE LEIDAPO FOSSIL ASSEMBLAGES,EARLY MIDDLE TRIASSIC OF QINGYAN,SOUTHWESTERN CHINA

作　　者：Stiller F Bucher H 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008 [2]Institute and Museum of Palaeontoiogy, University of Zurich, Zurieh, Switzeriand [3]Department of Earth Sciences, ETH, Zurich, Switzerland

出　　处：《古生物学报》2011年第1期1-12,共12页Acta Palaeontologica Sinica

摘　　要：贵州青岩地区的青岩组上部包括雷打坡段和渔庆段,其中,雷打坡段的化石特别丰富,为研究二叠纪末生物大灭绝后底栖动物的辐射和群落演化提供了十分重要的信息。根据青岩组雷打坡段和渔庆段的菊石重新研究,划分出两个组合:1)安尼期中期的最晚阶段(latest middle Anisian)的Bulogites-Acrochordiceras组合;2)安尼期晚期的最早阶段(earliest late Anisian)的Rieppelites-Judicarites组合。其中,Bulogites-Acrochordiceras组合包括了该时代的标志属Bulogites和Acrochordiceras,另有属Proarcestes,Sageceras和Beyrichitinae的未定属;此组合可与意大利北部和匈牙利的Bulogites zoldianus带对比,也可与美国内华达州西北部Balatonites shoshonensis带的Bulogites mojsvari亚带对比。Rieppelites-Judicarites组合包括了该时代的标志属Rieppelites和Judicarites,另有特征属Ptychites和Gosauites;该组合可与意大利北部的Rieppelites ci meganus带对比,也可与美国内华达州西北部Gymnotoceras weitschati带的Billingsites cordeyi亚带对比。上述组合表明,青岩剖面的青岩组最高层位并不包含安尼期最晚期沉积,因此,该组历程不等于整个安尼期。根据所得化石以及对已发表材料的复核,认为以往的"Paraceratites trinodosus"等安尼期晚期属种名单鉴定有误。青岩地区的安尼期中期/晚期界线在雷打坡段中部的靠下方。在富含化石的雷打坡剖面界线在其中部的靠上方。雷打坡化石组合的历程等于一个短时期,正好包围安尼期中期/晚期界线。Unusually diverse fossil assemblages from Leidapo near Qingyan,Guizhou Province of southwestern China,provide important information on the main post-extinction radiation of benthic invertebrates and on the evolution of biocoenoses in the Early Mesozoic.Precise biostratigraphical correlation and age determination of the strata yielding these fossil assemblages are therefore of great importance. Revised biostratigraphical correlation based on ammonoids shows that the Upper Qingyan Formation of the Qingyan region is of latest middle to earliest late Anisian age and that the middle/late Anisian boundary is situated in the upper middle part of the highly fossiliferous section at Leidapo.The Leidapo fossil assemblages thus span a short time interval,just bracketing the middle/late Anisian boundary.

关 键 词：化石组合 菊石 生物地层对比 年龄 安尼期中期/晚期界线 中三叠世 雷打坡 青岩 

分 类 号：Q915[天文地球—古生物学与地层学]