摘要
在前人工作的基础上,对华南和喜马拉雅地区晚二叠世一早三叠世不同生态类型的牙形石进行了详细研究,依水体深浅不同,从浅到深识别出5种牙形石生物相即Hindeodus生物相、Pachycladina-Parachirognathus生物相、Hindeodus-Gondolella生物相Gondolella-Neospathodus生物相和Xaniognathus生物相。通过对这些牙形石生物相在时间和空间上变化的分析,划分出3个牙形石生物区(Province),并依掘各区內不同生物相的变化,探讨了东特提斯部分地区海水进退变化的规律及其与生物大规模更替的关系。
Conodont paleoecology, biofacies and division of bioprovinces are very important for research on bioprovinces, paleogeography and global geological correlation in detail. Based on conodont data from Xizang, Sichuan, Guizhou, Guangxi, Hubei, Zhejiang and Anhui, as well as other contributions on conodont biofacies and bioprovinces in the world, the authors have investigated Changxingiau-Spathian conodont biofacies and bioprovinces in detail. According to the water depth required by various conodont assemblages, five conodont biofacies are recognized from shallow to deep water at different times: 1. Hindeodus conodont biofacies(tidal flat-lagoon), 2. Pachycladina-Parachirognathus conodont biofacies(subridal zone), 3. GondolellaHindeodus conodont biofacies(innershelf), 4. Gondolella-Neospathodus conodont biofacies(outer shelf), 5. Xaniognathus conodont biofacies(basinal). Analysis of the changes of conodont biefacies in time and space indicate that there are three conodont bioprovinces in Himalaya and South China. 1. The Himalayan province is characterized by Gondolella jubata, 2. the Upper Yangtze province is marked by Pachycladina obliqua and Parachirognathus geiseri, and 3. the Lower Yangtze province is characterized by Neospathodus homeri. Judging by the vertical changes of the conodont biofacies in the three bioprovinces, two transgression-regression cycles are recognized:(1) from Late Wujiapingian to Early Griesbachian and(2) from Late Griesbachian to Smithian. Biotic development and change are closely related with the transgression-regression cycles. Judging by the relation between mats biotic alternation and the transgression-regression cycles as reflected by the changes of conodont biofacies, the authors hold that changes in both appear to have proceeded quite harmonimously, and the change of sea level is one of the important causes of mass biotic alternation.
出处
《地质学报》
EI
CAS
CSCD
北大核心
1993年第4期367-375,共9页
Acta Geologica Sinica
基金
国际对比计划(IGCP)272项研究成果之一
关键词
牙形石
生物相
生物分区
海水进退
conodont biofacies, conodont bioprovincialism, transgression-regression cycle, Permian-Triassic conodont
