【摘要】 堰塞湖溃坝类型包括冰川、冰碛,火山和多种块体地貌(滑坡、崩塌、泥石流等)过程,而溃坝堆积相的种种特点以后者所造成的最具代表性。堆积体平面展布范围大(几平方公里~几十平方公里),剖面规模也大(高几十米),层次(层理)和结构全剖面均一,无超大的砾石;微观上有部分泥石流堆积特点,显示是高密度流,搬运介质是水。堆积体很少细砂和粘土物质。在平面上可划分出:扇顶(上游)、扇中(中游)、扇缘(下游)等微相。更多还原

【Abstract】 According to their dam modes of origin,dammed-lakes outburst deposits can be devided into glacierdammed-lakes and moraine-dammed-lakes,lava-dammed-lakes and mass movements( landslide,collapse,debris flow)- dammed-lakes. Furthermore,characteristics of sedimentary facies which are caused by mass movements are most representative. Our preliminary research and reference to others’ work on mass movements-dammed-lakes outburst deposits of several typical regions( Xuelongnang,Yinchanggou,Tangjiashan and the source region of Minjiang) demonstrate that spreading areas of many accumulated body are enormous ranging from several square kilometers to dozens of square kilometers; section sizes are also massive with heights of dozens of meters; layers( beddings) and structures in the whole profile are homogeneous without oversized gravels. Microscopically,certain features of accumulated body are similar to debris flow such as current of higher density with water as transporting media. Microfacies of accumulation body can be divided into fanhead( upstream),middle fan( midstream) and fan fringe( downstream).更多还原