“白云石问题”及其实验研究.pdf

2015年9月,第21巻,第3期,395-406页
高校地质学报
September 2015, Vol 21, No3, pp.395-406
Gcological Journal of China Univcrsitics
D)0T:10.16108/jisn1006-749.3.2015170
“白云石问题”及其实验研究
张亦凡,马怡飞,姚奇志,钱飞进,王雨晗,李涵,周根陶
1.中国科学院売幔物质与环境重点实验室,中国科学技术大学地球和空科学学院,合230026
2.中国科学技术大学化学与材料科学学院,合肥2.30026
摘要:“白云石同题”无疑是地质学上最有趣最长久的难题之ー。作为一种常见的碳酸盐犷物,白云石在地质历史时期大量
发育,却在现代海洋沉积环境中鲜少沉积,并在实验室模拟海水条件下也几予无法低温合成。白云石 Camg( CO3)l不同于
Ca、Mg2无序的高镁方解石,具有阳离子有序超结构,空间群为R-3,在地表条件下为热力学稳定相。尽管人们尝试模拟
自然界中白云石存在的物理化学条件,但却几乎没有从实验中成功合成有序白云石。在已有的实验室研究中,有序白云石
仪能通过高温水热实验形成。这说明白云石的形成极可能是一个动力学控制过程。而近些年被人们广泛接受的白云石微生
物成因模式认为微生物活动是低温白云石形成的关键,相关的微生物矿化实验也证実微生物的存在能够健进高镁方解石的
形成。对白云石问题的探讨不仅对理解白云岩成因具有重要意义,还能够促进矿物学理论研究发展。此次研究从高温合成
实验、低温合成实验、微生物协同沉淀实验等方面综述了有关自云石问题的实验室研究进展,阐明了目前对于白云石问题
认识的局限,有助于更好的理解“白云石问题”和具中所包含的物学和物理化学题,乃至于帮助寻找到它的答案
关键词:自云石问题;低温白云石;动力学控制因素;微生物成因模式
中图分类号:P588.24
文献标识码:
文章编号:1006-7493(2015)(03-0395-12
Dolomite Problem and Experimental Studies of
Idolomite Formation
ZHANG Yifan MA Yifei, YAO Qizhi, QIAN Feijing, WANG Yuhan, LI Han, ZHOU Gentao
1. CAS Key Laboratory of(rust-mantle Materials and Environments, School of Earth and Space Sciences, University of Science and
Tcehnology of China, Hcfci 230026, CH
School of Chemistry and Malerials Science, Universily of Science and Technology of China, Helei 230026. China
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 hisory but rarely ours in modern ocean dimes. I is nearly imposible to precipita
dolomite below 100. Dolomite, CAM(0 )2], has a cation ordering structure and its space group is R-3. Additionally, it
thermodynamically stable under the condition of earths surtace. Although researchers tried to mimic physical and chemical conditions of
nalural environments which can form dolomite, Ihese experimenls stillcan nol suc ss uly precipitate ordered dolomite. ully ordered
dolomite can only form in hydrothermal experiments upper 200 C. 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 lemperature. Many microbial mineralization experiments have confirmed that the existence of microorganisms
收稿日期;2015-(05-20;修回日期:2015-08-0
基金项目:国际重点基础研究发展计划资助项目(2014CB846003):国家白然科学基金(41372053);高等学校博学科点专项科研基金
(20133402130007)联合资助
作者简介:张亦凡,女,1993年生,倾十研究生,地球化学专业;ド:-mai: yilan(Qmail.uslc.edu.cn
通讯作者:周根陶,教授;E-mail:gtzhou(@uste.edu.cn