微生物席的特征和属性:微生物席沉积学的理论基础

Feature and nature of microbial-mat: Theoretical basis of microbial-mat sedimentology

微生物席是一个特别的微生物群落,构成了地球上形成最早、延续时间最长的生态系,这已经成为共识。但是,由于微生物席生物构成的复杂性、发育环境和产物的多样性,对微生物席的属性还存在不同的答案。不同的答案意味着不同的研究领域,因为对一个基本问题,即"究竟什么是微生物席",要获取一个单一的答案几乎是不可能的。微生物席定义的多重性答案,最终就成为地球生物学框架下一个年轻的沉积学分支——"微生物席沉积学"的概念体系和理论基础。最为重要的是,要穿越成岩作用"过滤器",去了解地质历史时期的微生物席建造物的生长机理和发育过程,还存在若干的困难,这些困难表现在几个重要的现象之中,如:(1)寒武纪叠层石中的底栖鲕粒;(2)中元古界灰岩层面上特别的MISS(微生物诱发的沉积构造);(3)中元古界叠层石白云岩序列中的凝块石。因此,基于微生物席的属性和特征所蕴含的微生物席的多样化定义,介绍微生物席沉积学的理论体系,对于深入理解这一年轻分支学科的现状和进一步发展具有特别重要的意义。

The microbial-mat is actually a special microbial community that forms a longest and earliest ecosystem on the Earth, which has been a common view. However, both the complexity of microbial compositions and the diversity of forming environment and product, lead to several answers for the nature of the microbial-mat. Furthermore, different fields of interest find their own answers, such as it seems almost impossible to find only one single answer to the question： What are microbial-mats？ Ultimately, the manifold answers of microbial-mats become the theoretical basis of the microbial-mat sedimentology, which is a young branch of sedimentology in the Earth＇s biological frame work. Most importantly, there are many difficulties for the further understanding of growth mechanism and formational process of the microbial-mat buildup in the geological history through the filter of the diagenesis. The problems are as follows： （1） benthic oolites within stromatolite of the Cambrian ; （2） particular microbially-induced sedimentary structures （MISS） on the limetone bedding surface of the Mesoproterozoic; （3） thrombolites within a stromatolitic deposition succession of the Mesoproterozoic. Therefore, on the basis of manifold definitions of the microbial-mat, a brief introduction of the theoretical basis of the microbial-mat sedimentology will be meaningful for the further understanding of both the advance and the present situation of this young branch of sedimentology.