砂岩中自生绿泥石的产状、形成机制及其分布规律  

The Occurrence,Growth Mechanism and Distribution of Authigenic Chlorite in Sandstone

作　　者：田建锋[1] 陈振林[2] 凡元芳[1] 李平平[3] 宋立军[1] 

机构地区：[1]西安石油大学油气资源学院,西安710065 [2]中国地质大学资源学院,武汉430074 [3]中国石油大学资源与信息学院,北京102249

出　　处：《矿物岩石地球化学通报》2008年第2期200-205,共6页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：陕西省教育厅专项科研基金资助项目(07JK364)

摘　　要：砂岩中自生绿泥有4种产状:颗粒包膜、孔隙衬里、孔隙充填和蜂窝状;3种成因类型:粘土矿物转化、物质的溶蚀结晶和富铁镁外来流体的渗入。时间形成顺序为:颗粒包膜绿泥石→孔隙衬里绿泥石→孔隙充填绿泥石;蜂窝状绿泥石的形成时间取决于外来流体的渗入时期。绿泥石的表面电荷特性受成岩流体pH的控制,并进而影响其产状。绿泥石的分布受铁镁物质的来源、孔隙流体性质、温度、砂岩的成分和结构控制,且不同产状的绿泥石具不同的空间分布规律,颗粒包膜绿泥石主要由沉积环境控制,孔隙衬里绿泥石由砂岩中富含铁镁的岩屑和黑云母等的分布约束,孔隙充填绿泥石受砂岩结构影响;蜂窝状绿泥石取决于外来流体的渗流特征。Authigenic chlorite is present as four different occurrences in sandstone： grain coatings chlorite, pore-lining chlorite, pore filling chlorite and honeycomb chlorite. The formation of authigenic chlorite consists of the transformation of clay minerals, the dissolution and crystallization of iron-rich substance, and the infiltration of external fluid which enriches in Mg or Fe. The sequences of different authigenic chlorite forms follows ： grain coatings chlorite→pore-lining chlorite→pore filling chlorite, and the timing of honeycomb chlorite growth is depended on the external fluid. The value of pH is relevant to the surface charge of chlorite, and influences the chlorite occurrence furtherly. The distribution of chlorite is controlled by the composition and structure of sandstone, the origin of Mg and Fe, temperature and pore fluid. The distribution of grain coatings chlorite, pore-lining chlorite, pore filling chlorite and honeycomb chlorite are different which are mainly dominated by sedimentary environment, the distribution of Fe-rich lithic fragment and biotite, the structure of sandstone and the external fluid respectively.

关 键 词：自生绿泥石 砂岩 成岩作用 产状 

分 类 号：P618.13[天文地球—矿床学]