陕西宁强埃迪卡拉纪晚期高家山生物群中黄铁矿化化石的成岩及风化过程  

FOSSIL DIAGENESIS AND WEATHERING OF PYRITIZED FOSSILS IN THE LATE EDIACARAN GAOJIASHAN BIOTA IN NINGQIANG,SHAANXI

作　　者：蔡耀平[1] 华洪[1] 

机构地区：[1]西北大学早期生命研究所,大陆动力学国家重点实验室,西北大学地质学系,西安710069

出　　处：《古生物学报》2008年第2期214-221,共8页Acta Palaeontologica Sinica

基　　金：西北大学研究生自主创新项目(No07YZZ27);国家自然科学基金(No40572015);国家重点基础研究发展规划项目(No2006CB806400);长江学者和创新团队发展计划联合资助

摘　　要：陕南埃迪卡拉纪晚期的高家山生物群中部分化石以黄铁矿化三维立体保存软躯体管状化石为主要特征。对野外识别出的具有不同风化程度的3类粉砂岩进行了详细的手标本特征对比和扫描电子显微镜测试对比研究。锥管虫(Conotubus)的化石成岩学特征表明黄铁矿最先沉淀,随后方解石充填于黄铁矿留下的空隙或空腔中。这些化石所经历的第一期风化作用相对较弱,保留了大量的原始化石成岩学信息;第二期风化作用则可能形成于一个氧化条件较强的环境中。The Gaojiashan biota known from Ningqiang County of Shaanxi Province, China, is characterized by the three-dimensional pyritization of softbodied fossil tubes. Three types of fossiliferous siltstones have been identified in the filed and detailed observations as well as comparisons of diagenetic and weathering attributes have also been documented. Fossil diagenetic characteristics of Conotubus indicate that pyritization initiated firstly and calcite infilling followed. Pyritized Gaojiashan fossils have been subjected to two series of weathering and the former had minor influence on the pyritized fossils, whereas the latter destroyed much of the diagenetic attributes and most likely took place in an oxidative environment.

关 键 词：高家山生物群 黄铁矿 化石成岩 风化作用 埃迪卡拉纪 宁强 陕西 

分 类 号：Q911[天文地球—古生物学与地层学]