贵州花溪P-T界线附近粘土矿物结构及成因意义  

Fine Structure and Their Genetic Significance of Clay Minerals from the Permian-Triassic Boundary,Huaxi Area,Guizhou Province

作　　者：高文鹏[1] 洪汉烈[1,2] 殷科[1] 赖旭龙[1,2] 王朝文[1] 李荣彪[1] 杨博[1] 刘欣[1] 

机构地区：[1]中国地质大学地球科学学院,湖北武汉430074 [2]中国地质大学地质过程与矿产资源国家重点实验室,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2013年第6期1253-1262,共10页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目(Nos.41072030;40872038)

摘　　要：为了揭示贵州花溪区海相P-T界线附近粘土岩的成因及物质来源,采用X射线衍射(XRD)、扫描电子显微镜(SEM)以及差示扫描量热法(DSC),对粘土层中粘土矿物的精细结构进行了深入的研究.结果表明,样品中的粘土矿物共有两种物质来源.样品YN06质地致密,粘土颗粒具有一定的定向性,主要粘土矿物成分为伊利石和少量绿泥石.粘土矿物颗粒具有不规则的轮廓及参差不齐的边缘;样品脱羟基反应温度为590℃,表明样品中的伊利石主要为tv结构,来源于陆地机械风化作用.其余五件样品主要粘土矿物为伊蒙规则混层和伊利石以及少量蒙脱石、绿泥石,脱羟基温度均大于600℃,表明样品中的粘土矿物主要以cv结构为主,含有少量的tv结构,指示粘土岩主要来源于火山物质的蚀变并伴随部分陆源碎屑物质沉积形成.The fine structure and provenance of clays across the Permian-Triassic boundary （PTB） in the Yanlou section were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and differential scanning calorimetry （DSC）. The results suggest that the layers have two different provenances. The sample of YN06 exhibits a condensed texture with an oriented arrangement of detrital clay particles and consists mainly of illite and minor chlorite, with irregular outlines or ragged edges. The dehydroxylation temperature occurred at 590℃, indicating that clay minerals are composed of trans-vacant （tv） octahedral sheets derived from weathering of detrital illite. Other samples are composed mainly of I-S, illite and minor smecrite, chlorite, with dehydroxylation temperature all above 600 ℃, suggesting that clay minerals consist of a mixture of tv and cv sheets and were derived from a mixture of terrigenous and volcanic sources.

关 键 词：二叠-三叠系界线 粘土矿物 火山岩 精细结构 

分 类 号：P571[天文地球—矿物学]