微生物硅化研究进展——对前寒武纪硅质岩成因和硅循环的启示  

Review on microbial silicification——Implication for the Precambrian siliceous rock genesis and silicon cycle

作　　者：李绍瑞 赵东方[1,2] 谭秀成 胡广[1,2] 罗文军 苏琛[3] 曾建军 邓禹 吴昊 LI Shaorui;ZHAO Dongfang;TAN Xiucheng;HU Guang;LUO Wenjun;SU Chen;XU Wei;ZENG Jianjun;DENG Yu;WU Hao(Southwest Petroleum University,State Key Laboratory of Oil and Gas Geology and Exploitation,Chengdu,610500;Southwest Petroleum University,Division of Key Laboratory of Carbonate Reservoirs,CNPC,Chengdu,610500;Research Institute of Exploration and Development,PetroChina Southwest Oil&Gasfield Company,Chengdu,610041)

机构地区：[1]西南石油大学,油气藏地质及开发工程国家重点实验室,成都610500 [2]中国石油集团碳酸盐岩储层重点实验室西南石油大学研究分室,成都610500 [3]中石油西南油气田分公司勘探开发研究院,成都610041

出　　处：《地质论评》2025年第2期670-682,共13页Geological Review

基　　金：中国石油—西南石油大学创新联合体科技合作项目(编号:2020CX010300);国家自然科学基金青年基金资助项目(编号:42302169)的成果。

摘　　要：硅质岩作为一类广泛分布于地质历史时期的化学—沉积岩,在古环境、古气候及古生物领域有着独特的研究价值。近年来,随着硅质矿物沉淀过程中微生物参与的证据不断丰富,微生物硅化模式逐渐受到学者们的关注。但关于微生物在硅质矿物沉淀过程中的角色,目前仍有不同认识。前人普遍认为微生物在硅质矿物沉淀中起“被动”作用,即在溶解硅过饱和的条件下,微生物及其代谢产物为硅质矿物沉淀提供成核位点,再通过阳离子桥接、氢键结合或静电吸引等方式,使得硅质矿物在微生物表面沉淀。但最近研究发现,即使在溶解硅欠饱和的条件下,前寒武纪广泛存在的微生物通过Mg^(2+)桥接也能促进硅质矿物沉淀。这意味着溶解硅过饱和并非前寒武纪硅质岩形成的必要条件,进一步暗示前寒武纪海水溶解硅浓度可能被高估,并未达到饱和状态。同时,微生物硅化过程中硅化基因的表达也暗示了前寒武纪海水溶解硅浓度可能早在中元古代就开始降低,远早于前人预测的新元古代晚期—寒武纪早期。由此可见,微生物硅化对完善地质历史时期海水硅循环模式起着至关重要的作用,但准确评估溶解硅浓度降低的时间和具体溶解硅浓度仍是亟待解决的问题,还值得进一步探索和更细致的研究。Objectives:Siliceous rocks,as a type of chemical—sedimentary rocks widely distributed in geological history,have unique research value in the fields of palaeoenvironment,palaeoclimate and palaeontology.In recent years,with the increasing evidence of microbial participation in the process of siliceous mineral precipitation,the microbial silicification model has gradually attracted attention from scholars.However,the role of microorganisms in the process of siliceous mineral precipitation is still controversial.Results:Previous studies generally believed that microorganisms play a"passive"role in siliceous mineral precipitation,that is,under the condition of supersaturated dissolved silicon concentration,microorganisms and their metabolites provide nucleation sites for siliceous mineral precipitation,and then through cation bridging,hydrogen bonding or direct electrostatic interactions,the siliceous minerals are precipitated on the surface of microorganisms.However,recent studies have found that even under the condition of unsaturated dissolved silicon concentration,the widely existed microorganisms in the Precambrian can also promote siliceous mineral precipitation through Mg^(2+)bridging,which means that the supersaturation of dissolved silicon is not a necessary condition for the formation of Precambrian siliceous rocks,further suggesting that the concentration of dissolved silicon in Precambrian seawater may have been overestimated and did not reach saturation..Simultaneously,the expression of Silicon Transporters(SITs)during microbial silicification also suggests that the dissolved silicon concentration in Precambrian seawater may have begun to decrease as early as the Middle Proterozoic,earlier than the Late Neoproterozoic—Early Cambrian predicted by previous researchers.Conclusions:Therefore,microbial silicification plays a crucial role in the seawater silicon cycle model in geological history.However,the accurate assessment of the time of the decrease in dissolved silicon concentration and the specific

关 键 词：微生物硅化 硅循环 硅质成因 硅质矿物 前寒武纪 

分 类 号：P61[天文地球—矿床学]