"Dolomite problem" has long been one of the focuses and difficulties in the study of sedimentary geology. Dolomite serves as an important reservoir of oil and gas both in China and abroad. Therefore, the understanding of the formation process of dolomite is significant for the exploration of oil and gas in carbonate rocks. There are many models to explain the origin of dolomite, such as the Sabhka evaporation model, the seepage-reflux model, the burial adjustment model, the mixing zone model, and the tidal pumping model. During the past decades, with the further research on the dolomite formation at low temperature, the microbial dolomite model, as a new dolomite origin model, was proposed and well developed. This paper reviews the progress of research on microbial dolomite. Three kinetic barriers of dolomite precipitation under earth surface conditions were listed, which are strong hydration energy of magnesium ion, the existence of sulfate ion and the low concentration and low activity of carbonate ion. The background for putting forward the microbial dolomite model and the growth process and morphological characteristics of microbial dolomite were briefly described. The mediation of microbeduring the formation process of dolomite was explained in detail. It is pointed out that the existence of microbes (e. G., sulfate-reducing bacteria and ancient methane bacteria) could change the ion balance of solution and help dolomite to overcome the kinetic barriers during the precipitation process. The application of oxygen isotope of microbial dolomite to the reconstruction of palaeo-temperature and ancient climate change was discussed. The future orientations for research on microbial dolomite (e. G., multidisciplinary analysis, application of high technology etc.) were predicated. The further investigation into the microbial dolomite model will provide researchers with a new approach to understanding the "dolomite problem" and is also helpful to the study of dolomite reservoir in petroleum geology.%“白云岩问题”一直是沉积地质学研究的热点和难点之一,白云岩在我国和世界范围内都是重要的油气储层.因此,深入认识白云岩成因对于碳酸岩油气勘探具有重要参考意义.白云岩成因有多种解释模式,如萨布哈蒸发模式、渗透回流模式、埋藏调节模式、混合水模式、潮汐泵模式等.近几十年来,随着低温白云石研究的不断深入,微生物白云石模式作为一种新的成因模式被提出并不断被完善.本文回顾了微生物成因白云石的研究进展,总结了低温白云石形成的3个动力学障碍(镁离子的高水合能、硫酸根的存在、碳酸根离子的低浓度和低活度),简要介绍了微生物成因白云石模式的建立、微生物成因白云石的生长过程及发育特征,系统分析了微生物在白云石形成过程中的调节作用,指出微生物(如硫酸盐还原菌、古甲烷菌)的存在可以改变溶液中的离子平衡,进而有利地克服白云石形成过程中的动力学障碍,并列举了低温微生物成因白云石的氧同位素指标在古温度恢复和过去气候变化研究中的应用,最后对微生物成因白云石相关研究方向(如多学科交叉、新技术应用等)加以展望.对微生物成因白云石模式的深入认识,将为正确解释“白云岩问题”提供新的途径,也将为石油学家关心的白云岩储层问题提供新的理论基础和研究思路.
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