微生物碳酸盐岩研究进展及存在的问题

通过对国内外有关微生物碳酸盐岩的成因、分类资料的广泛阅览和对比分析,发现以蓝藻菌、减硫酸盐细菌、产甲烷细菌为主的微生物在新陈代谢过程中能够改变水体的物理化学条件而促使Ca2+、Mg2+发生沉积,或是对外来碎屑进行捕捉和粘附,或是发生自身钙化,从而引导微生物碳酸盐岩的形成。依据形成机制和宏观构造将微生物碳酸盐岩划分为叠层石、凝块石、树形石和均一石,初步建立了微生物碳酸盐岩的分类体系,是碳酸盐沉积学中的重大进展。另外,应将同样具有特殊宏观构造和重大地质意义的核形石、纹理石与叠层石、凝块石、树形石和均一石并列,归为微生物碳酸盐岩。

Progress and Problems in Microbial Carbonates Research

By extensively reading,contrasting and analyzing a variety of references of the formation and classification methods for microbial carbonate,it is found that some kinds of microbes,such as cyanobacteria,sulphate-reducing bacteria,methanogenic bacteria and so on,in theirmetabolic activities can change physiochemical conditions of microenvironment,which results in the precipitation of Ca2+ and Mg2+,microbes also can catch and adhere allochthonous grains and can be self-calcified,all activities above finally cause the formation of microbial carbonate rocks.On the basis of the formation mechanism and macrofab rics microbial carbonate can be classified in to stromatolite,throm bolite,dendrolite and leiolite,which preliminarily established classification system and was agreat progress in carbonate sedimentology.In addition,Oncolite and Laminite also with special macrofabrics and important geological significance should belong to microbial carbonates in parallel with stromatolite,thrombolite,dendrolite and leiolite.