重庆巫溪红池坝长兴阶深水相沉积记录及地质意义

摘要

The deep-water sediments were well developed along the Hongchiba section in Wuxi County,Chongqing,which is represented by a series of Upper Changhsingian conodonts and deep shelf trace fossils.Based on the assemblage zone of conodont observed from the Hongchiba section,the Upper Changhsingian sedimentary feature and facies were investigated,and the controversial viewpoints on the boundary between Dalong Formation and Changxing Formation were discussed.During the Middle-Late Changhsingian,the sedimentary environment shifted gradually from a deep-water basin to a deep-water shelf,giving rise to unstable marine ecological environment.The analysis of trace fossil records with time series points to the unstable fluctuation change of oxygen levels in deep-water shelf facies through the Middle-Late Changhsingian.It also reflects the interaction between biology and environment when the critical geologic interval has been approaching.%重庆巫溪红池坝剖面长兴阶上部地层出露齐全,产系列牙形刺和深水陆棚相遗迹化石.通过建立牙形刺带,对该剖面长兴阶沉积相类型及特征进行了精细研究,并讨论了区域大隆组/长兴组界线的时代归属.长兴中—晚期开始,沉积环境由深水盆地向深水陆棚逐渐过渡,海洋生态环境的不稳定性开始显现并持续发展,基于时间序列的遗迹化石记录详细刻画了深水陆棚水体含氧量频繁加速波动过程,为系统审视二叠纪末生物与环境协同演化提供了重要依据.