摘要
根据近年来确定的国际年代地层界线标准讨论了柴达木盆地北缘石炭系的顶、底界线。把石炭系的底界置于陆相沉积的阿木尼克组和海相沉积的穿山沟组之间。认为阿木尼克组可以与泥盆、石炭纪之交的全球性海退事件层对比 ,穿山沟组底界是这个海退事件层之上的海进面 ,相当于三级层序初始海泛面。把石炭、二叠系界线置于扎布萨尕秀组上段类Pseudoschwagerina组合带或Sphaeroschwagerina带之底部。这个界线大体相当于以牙形石Streptognathodusisolatus首现为标志确定的二叠系底界。
In the present paper the recognition of the top (Carboniferous Permian) and base (Devonian Carboniferous) boundaries in the northern margin of the Qaidam Basin is discussed in terms of global chronostratigraphic standards. The Devonian Carboniferous boundary is set at the boundary between the continental facies Amunike Formation and the marine facies Chuanshangou Formation. The Amunike Formation may be correlated with the eustatic fall event beds near the Devonian Carboniferous Boundary (DCB), and the base boundary of the Chuanshangou Formation is represented by the transgressive surface corresponding to the first flooding surface of a third order sequence immediately above the eustatic fall event beds near the DCB. The Carboniferous Permian boundary in the area is drawn at the base of the fusulinid Pseudoschwagerina Assemblage Zone (or the Sphaeroschwagerina Biozone), which corresponds on the whole to the Carboniferous Permian boundary determined by the first appearance of the conodont Streptognathodus isolatus.
出处
《地学前缘》
EI
CAS
CSCD
2002年第3期65-72,共8页
Earth Science Frontiers
基金
国家自然科学基金资助项目 ( 4 0 172 0 14 )
中国石油天然气股份有限公司"十五"重点科研项目
"中国北方油气区石炭-二叠系划分对比
古环境研究及含油气远景评价"
中国地质调查局基础地质综合研究项目"中国古大陆环境变化及其年代
生物
层序
事件
化学和
