豫西寒武纪叠层石演化特征及其与后生动物的耦合关系

摘要

As the construction of microbial mats,stromatolites recorded a large number of palaeoclimate and palaeogeographic information.Eighteen layers of stromatolites are found in the Cambrian settings in western Henan.Based on macro and micro characteristics,the Cambrian stromatolites can be divided into 6 types of assemblages according to the abundance(thickness) and the diversity(morphological types).The episodic evolution is discussed as microbiolite-stromatolites and microbolite-limestone evolution scene according to the micro laminations,microbial fossils and microbial mats,combined with the characteristics of sedimentology and biological fossil of stromatolites in each type assemblages.According to the density relationship between the microbolites and trace fossils in Middle Cambrian limestone,the relationship between the stromatolite-microbolite evolution and metazoan is not simple waxing and waning but dynamic-balance coupling in the whole Cambrian.%作为微生物席建造物的叠层石记录了大量的古环境和古地理信息,在豫西寒武系出露18层叠层石,以宏观和微观沉积特征为基础,依据各组段叠层石丰度(层厚度)和分异度(形态类型)的演化,将豫西寒武纪叠层石划分为6个演化组合.从叠层石组合的微观纹层、微生物化石及其微生物席演化等方面,结合沉积学和生物化石特征,探讨了豫西寒武纪叠层石的幕式演化,分别为微生物岩-叠层石演化幕和微生物岩-灰岩演化幕.以中寒武世灰岩中微生物岩与遗迹化石的密度关系为例,并从整个寒武纪微生物岩与后生动物化石之间关系的角度分析,认为叠层石微生物岩演化与后生动物之间并非只是简单的“此消彼长”,而是一种动态平衡的耦合关系.