海底冷泉环境中的白云石(岩)研究现状
Research Progress of Dolomite in Seep Carbonates

卞友艳陈多福

文摘	白云岩成因问题一直是个未解之谜,近年提出的微生物成因模式受到了广泛关注。白云石在现代和古代冷泉环境中普遍发育,以白云石为主的冷泉白云岩主要呈烟囱状和管状产出,微观上可见菱形白云石,也有梭形和哑铃状的白云石。冷泉白云石碳同位素值变化较大,指示了可能主要来源于冷泉渗漏甲烷、海水溶解无机碳、有机质氧化和产甲烷残余的CO_2等,而氧同位素值的变化可能与甲烷水合物的生成与分解、黏土矿物的脱水和沉积温度等有关。半封闭的冷泉渗漏环境中的微生物甲烷缺氧氧化和硫酸盐还原作用可能有利于白云石的沉淀。与微生物实验相结合的冷泉白云岩研究可能是“白云岩问题”取得突破的新方向。
其他语种文摘	The origin of dolomite is a long-standing problem in geology,which is the so-called “dolomite problem”. Recently,microbial dolomite mechanism attracts significant attention.Dolomite is ubiquitous in modern and ancient seep carbonates and the seep dolostone often occurs as chimney and tube.Rhombic dolomite,spindle-shaped and dumbbell dolomite are generally observed in micro scale.Their widely varied carbon isotopic values imply mixed carbon sources,including methane (biogenic methane and thermogenic methane),dissolved inorganic carbon of seawater, organic matter of sediments and residual CO_2 from methanogenesis.Variable oxygen isotopic values may relate to formation and decomposition of gas hydrate,dehydration of clay minerals,and formation temperature.The anaerobic oxidation of methane and sulfate reduction at sem-i closed seep environment might be suitable for dolomite precipitation.The research of seep dolomite coupled with bacteria-mediated laboratory study would possibly provide a hopefully direction for solving “dolomite problem”.
来源	矿物岩石地球化学通报 ,2014,33(2):238-246 【核心库】
DOI	10.3969/j.issn.1007-2802.2014.02.012
关键词	冷泉白云岩 ; 沉积特征 ; 碳和氧同位素 ; 微生物成因
地址	中国科学院广州地球化学研究所, 中国科学院边缘海地质重点实验室, 广州, 510640
语种	中文
文献类型	综述型
ISSN	1007-2802
学科	地质学;海洋学
基金	国家自然科学基金资助项目 ; 中国科学院广州地球化学研究所135项目
文献收藏号	CSCD:5142532