微生物白云岩形成机制研究进展与存在问题

近年来,有关微生物白云岩沉淀作用机制的研究拓宽了沉积学中"白云岩问题"研究的视角。硫酸盐还原反应、产甲烷作用、有机分子水解等一系列可促进沉淀白云石的微生物代谢机制的发现,延伸了微生物白云石(岩)形成模式;有关可溶解硫化物催化白云石沉淀的研究,不但强调了硫酸盐还原反应机制,也为重新认识硫酸盐还原反应促进白云石沉淀机理提供了新线索。在现代环境中,微生物席内的原生白云石沉淀的发现,将微生物过程引入地表环境原生白云石沉淀作用和机理的研究,可能为寻找地层记录中的微生物白云石提供了更多有益的工作手段和思考途径。然而更加复杂的白云岩地层记录说明,运用微生物白云石去解释复杂的地质记录还存在着较多的局限性。

STUDY ADVANCES AND EXISTED PROBLEM FOR THE FORMING MECHANISM OF THE MICROBIAL DOLOMITE

In the recent years,the study on the forming mechanism of the microbial dolomite broadens the concept of "dolomite problem" perspective in the sedimentology.The sulfate reduction reaction,methane producing action,organic molecular hydrolysis and many other related topics help in the discovery of the microbial metabolic mechanism of the precipitated dolomite and moreover expand the forming model of the microbial dolomite;the researches related to the catalyzed dolomite precipitation by the resolvable sulfide not only emphasize the reduction reaction mechanism,but also provide the new clue of the dolomite precipitation mechanism with the help of the re-understandings of the sulfate reduction reaction.The studies on the modem sedimentary environments have highlighted the precipitation of the primary dolomite induced by the microbial accretion,and furthermore may provide more thoughtful operating measures and thing approaches for the finding of the microbial dolomite in the stratigraphic record.But the more comprehensive dolomite stratigraphic records show that there exit much more limits in the geological records interpreted by the microbial dolomite.