西藏吉隆地区白垩纪复理石相遗迹化石及其地质意义

Trace fossils of Cretaceous flysch facies in the Gyirong area,Tibet,and their geological significance

系统描述了西藏南部吉隆地区白垩纪甲不拉组和宗卓组首次发现的复理石相遗迹化石5属、7种。主要遗迹属有Chondrites,Cosmorhophehelminthoida,Muensteria,Phycosiphon,Phymatoderma。遗迹化石的形态、习性、水深分布等环境成因特征清楚地显示其为深海Nereites遗迹相的典型代表,反映复理石相深水沉积环境特征。

This paper systematically describes five genera and seven species of trace fossils of flysch facies found for the first time in the Cretaceous Jiabula Formation and Zongzhuo Formation in the Gyirong area,southern Tibet.The main genera of trace fossils are Chondrites,Cosmorhophe helminthoida,Muensteria,Phycosiphon and Phymatoderma.The forms ,habits and water depth dis tribution of the trace fossils may clearly prove that the trace fossils are typical representatives of the abyssal Nereites ichnofacies,reflecting the features of the flysch facies deep-water sedi mentary environment.