西藏羌塘南部地区的冰海杂砾岩及其成因  

ICE-SEA MIX-CONGLOMEATES AND THEIR GENESIS IN THE SOUTHRN AREA OF QIANGTANG,TIBET

作　　者：李才[1] 程立人[1] 胡克[1] 洪裕荣 

机构地区：[1]长春地质学院地球科学系,西藏地科所

出　　处：《长春地质学院学报》1995年第4期368-374,共7页

基　　金：国家自然科学基金;地质行业基金

摘　　要：青藏高原及邻区广泛分布的漂砾层、杂砾岩、含砾板岩是一种特殊的冰海相沉积岩，称为冰海杂砾岩（Ｉｃｅ－ｓｅａＭｉｘ－ｃｏｎｇｌｏｍｅｒａｔｅｓ）。它们和一起产出的冷水型动物群、耐冷植物群视为这一地区冈瓦纳相最典型的标志，代表着冈瓦纳大陆上塔尔切尔（Ｔａｌｃｈｉｒ）冰期所影响的时间和空间。除“标准型”冰海杂砾岩外，羌塘腹地发现了蛇绿质和钙质冰海杂砾岩。这两种冰海杂砾岩的发现，不但丰富了冰海杂砾岩的家族成员，同时也为冰海沉积、物质来源问题、冈瓦纳大陆北界及特提斯演化研究提供了新的信息。经研究，冰海杂砾岩中的砾石来自印度半岛──冈瓦纳大陆本体，以冰筏为载体融冰落石成因。Boulder gravels,mixing conglomerates and gravel-bearing slate,aspecial type of sedimentary rocks,widely distributed in Qinghai-Xizang plateau and itscontiguous region,are called Ice-sea Mix-conlomerates. They and the syngenatic coldwater type fauna and flora,are regarded as the most typical symbol of Gondwana faces inthis district,and represent the spatial and temporal effects of Talchir glacial period onGondwana continent.The ophiolitic and calcareous Ice-sea Mix-conglomerates havebeen discovered in Jaomuri、Xianshuiquan、Mayigangri、Naro,etc,besides“standard”Ice-sea Mix-conglomerates. This discovery not only adds the new members to the family ofIce-sea Mix-conglomerates but also provides new information for Ice-seasedimentation and material source discussion. It is concluded that the gravels in theMixing conglomerates come from India peninsular,the Gondwana continent and originatefrom drop-pebbles carried by Ice-draft.

关 键 词：冰海杂砾岩 冈瓦纳 冰海相 沉积岩 西藏 杂砾岩 

分 类 号：P588.212.5[天文地球—岩石学]