自生泥晶:过去,现在和未来

Automicrites:Past,Present and Future

自生泥晶,也称作原地微晶碳酸钙或原地灰泥以区分他生泥晶或异地泥晶,指的是通过无机和/或有机媒介过程作用在原地形成的泥晶碳酸钙。在前人的基础上,对自生泥晶概念的提出和发展进行了概括;对自生泥晶的矿物组成、显微结构、荧光和阴极发光特征进行了总结;对自生泥晶的形成过程和来源(包括生物矿化作用、有机矿化作用和无机沉淀三种方式)进行了探讨;对自生泥晶在不同沉积环境碳酸盐岩中的贡献及其地球化学指示进行了论述;对自生泥晶在地质历史时期的分布做了归纳;最后对自生泥晶的后续研究提出了一些展望。认为正确认识自生泥晶的性质,其形成过程和来源对碳酸盐岩的结构成因分类、地质历史时期生物礁丘的演化和地球化学指示、建筑工程和环境修复、探寻地外生命和油气地质等方面都将产生深远的影响。

The term‘automicrites’,also known as in situ microcrystalline Ca-carbonate,or‘lime mud’in places,is used to distinguish them from allomicrites(allochthonous micrites).Automicrites are the microcrystalline calcium carbonate formed in situ by inorganic-and/or organic-mediated processes.On the basis of previous studies,this paper(1)summarizes the proposed development of the concept of automicrites;(2)generalizes the mineral composition,microstructure,fluorescence and cathodoluminescence microscopic characteristics of automicrites;(3)discusses the formation process and genesis of automicrites(including biomineralization,organomineralization and inorganic pre⁃cipitation);(4)describes the contributions of automicrites to different carbonate depositional environments and their geochemical index;(5)sets out the distribution of automicrites during the history of the Earth;and finally(6)pro⁃poses some prospects for the future study of automicrites.It is believed that a correct understanding of the nature of automicrites,their formation process and origins will have a profound impact on the textural-genetic classification of carbonate rocks,the evolution and development of carbonate reefs and mounds and the geochemical index in geologi⁃cal history,architectural engineering and environmental restoration,and the exploration for extraterrestrial life,as well as hydrocarbon exploration.