关键词: 白云石问题, 低温白云石, 动力学控制因素, 微生物成因模式

Abstract:

Dolomite problem is undoubtedly one of the most interesting and confusing problems in geology. As a common carbonate mineral, dolomite is abundant in geological history but rarely occurs in modern ocean sediments. It is nearly impossible to precipitate dolomite below 100℃ . Dolomite, [CaMg(CO3)2], has a cation ordering structure and its space group is R-3. Additionally, it is thermodynamically stable under the condition of earth's surface. Although researchers tried to mimic physical and chemical conditions of natural environments which can form dolomite, these experiments still can not successfully precipitate ordered dolomite. Fully ordered dolomite can only form in hydrothermal experiments upper 200℃. It seems that the formation of dolomite is a dynamically controlling process. Recently, microbial dolomite model has been widely accepted. In this model, microbial activity is considered as the key of dolomite formation at low temperature. Many microbial mineralization experiments have confirmed that the existence of microorganisms canindeedpromotetheformationofhigh-magnesiumcalcite.Solving“dolomiteproblem”cannotonlyhelpunderstandingthegenesisof dolomite, but also promote the development of mineralogy theory. This review summarized current progresses of dolomite synthetic experiments,includingexperimentsathighandlowtemperaturesandmicrobiallyinducedexperiments.Wealsoclarifiedthelimitationsof currentunderstandingto“dolomiteproblem”.Futureperspectiveswereproposedtobetterunderstandandfinallysolvedolomiteproblem

Key words:  dolomiteproblem;lowtemperaturedolomite;dynamiccontrolfactors;microbialdolomitemodel