广西田东剖面二叠纪-三叠纪之交的生物绝灭及生态演化

本文以广西田东地区浅海相二叠系-三叠系剖面为研究对象,对二叠纪-三叠纪之交的生物绝灭与浅海生态环境演化进行了深入的探讨。镜下化石鉴定与统计结果表明在P/T界线附近生物物种两次急剧减少,一次为生物大绝灭所致,另一次为生物迁徙所致。另外,本剖面上所研究的物种的数量变化是突变的,而不是渐变的。在残存期内,腹足类生物较有孔虫生物表现出较强的自我恢复和适应环境的能力。整个剖面沉积为一个海浸的过程,其二叠系-三叠系界线之交生态环境发生了很大的变迁。

Organism Extinction and Ecology Evolution near the Boundary of Permian and Triassic in Tiandong, Guangxi Provience

This research focuses on the Permian/Triassic section of shallow marine facies in Tiandong area Guangxi province in south China.It tries to have a through discussion of shallow marine organism extinction and ecological evolution near the boundary of Permian and Triassic.The fossil identification and statistics in cross-microscope suggest that there are two organism sharp decrease near the Permian and Triassic boundary,one decrease is the result of a organism extinction;Another is the result of a organism migration.The extinction is not change gradually but it change suddenly.In the survival period,Gastropoda has stronger ability of self-recovering and adapting to environment than foraminiferida.The entire section deposition is a process which a sea soaks.At the same time,the sedimentary and ecological environment suffers from a strong variation near the boundary of Permian and Triassic.