Calcified Biofilms from Cambrian Oolitic Limestones in China  

作　　者：LIU Wei ZHANG Xingliang 

机构地区：[1]State Key Laboratory of Continental Dynamics, and Department of Geology, Northwest University

出　　处：《Acta Geologica Sinica(English Edition)》2015年第1期70-76,共7页地质学报（英文版）

基　　金：financial support from the Major Basic Research Project of the Ministry of Science and Technology of China(Grant:2013CB835002);the Natural Science Foundation of China(Grants:41272036);the China Postdoctoral Science Foundation(Grant:2014M552481);the"Sanqin Scholarship"project of the Shaanxi Authority

摘　　要：Calcified biofiims are preserved as thin micritic coatings in the Cambrian oolitic limestone of two sections in North and South China. Standard petrographic examination revealed that the biofilms were developed during the early diagenetic stage immediately after the freshly deposited ooids, proceeding in the continuous sequence of depositional processes. The biofilm outlines are highly irregular, with steep sides, tower-like structures and overhanging projections; the internal fabric of the biofilms is composed of roughly laminated micrite aggregates with channel-like structures. Biofilms exhibit a strong fluorescent reaction. Detailed SEM examination suggests that the biofilms are biotically dominated by cyanobacteria. Our study demonstrates that microbial colonies, such as biofilms, can develop on ooid cortices and influence the formation and microstructures of those ooids.Calcified biofiims are preserved as thin micritic coatings in the Cambrian oolitic limestone of two sections in North and South China. Standard petrographic examination revealed that the biofilms were developed during the early diagenetic stage immediately after the freshly deposited ooids, proceeding in the continuous sequence of depositional processes. The biofilm outlines are highly irregular, with steep sides, tower-like structures and overhanging projections; the internal fabric of the biofilms is composed of roughly laminated micrite aggregates with channel-like structures. Biofilms exhibit a strong fluorescent reaction. Detailed SEM examination suggests that the biofilms are biotically dominated by cyanobacteria. Our study demonstrates that microbial colonies, such as biofilms, can develop on ooid cortices and influence the formation and microstructures of those ooids.

关 键 词：GEOBIOLOGY OOIDS MICRITE cyanobacteria CAMBRIAN Hubei and Shaanxi provinces 

分 类 号：Q73[生物学—分子生物学]