希夏邦马峰东南富曲河谷的冰川沉积和冰川构造

Glacial Deposits and Glaciotectonics in Fuqu River Valley on the Southeast Slope of MT. Xixabangma

在希夏邦马峰（海拔８０１２ｍ）东南富曲河谷，中更新世以来有三次冰期；即聂拉木、富曲和普罗冰期。它们均可再分为两个亚阶段。聂拉木南的高冰碛平台长３．５ｍ，宽１．５ｋｍ，厚２００ｍ。属于中更新世聂拉木冰期（聂聂雄拉冰期）的巨大山谷冰川沉积，中尼公路从高冰碛平台尾端通过，形成数公里长的冰碛剖面，呈现出美丽多姿的冰川成因类型沉积和冰川构造现象，包括冰下，冰上融出碛，冰内．冰下河道沉积，冰湖沉积，坠碛，流磺等。冰川运动时造成的冰川构造，如断层、滑动面—…等也很清楚，代表了海洋型（暖冰川）冰川沉积和冰川构造特征，是中国目前研究冰川构造最理想的场所。

Abstract-Four glacintioos Can be recognized, in Pleistocene of Mt. Xixabangma Region,from old to new named, Xixabangma, Nyanyaxungla, Qomolangma I (Jilong Temple) and Qomolangma Ⅱ(Rongbu Temple),equivalent to Nebraskan, Kansan, Illinolian and Wisconsinian Glacistion in Mountain region in North America.Nysnyaxungla Glaciation was the maximum in glacial extent in this region. At the time glacierscoveted over the whole of the Fuqu valley, which deStructed the glacial deceitS in XhabanglnaGlaCtalion almOSt complstely. There iS only glacial traces ftoffi the last thtee glaciations sinal theMiddle Pleistocene, and a serieS of end moraines is in the HOlocene they are NyaAn, Fuqu and Pulou Glaciations, which each glaciation can be also divided into two substages. A higher moraine plateform is extended in south of Nyalam, which is 1. 5km wide, 3. 5km long and 300m above Nyalam, with yellow blown soil on the surfs de overlying a ted peleosol layer, the tin about 200m thick, The moraine Plateform is the great valley glacier deposits of Nyalam (Nyanyaxangla)Glaciation of the Middle Pieistocene, A several kilometers moraine section is ex￣ at the end ofthe Platform because of the Chinese-Nepal Highway cut over, and may be oboved complexdeposits facise and glaciqtectonics, inding superglacial and subglacial meltout tills, now till,logement till, dump till, englacial-subglacial meltwater channel depeits, glacial lacutrine sediments, droping boulders of floating ice, deformation till. The glaciotectonic and depositional structures, such as thrust Plane. collagse strUcture, sliding plane and so on, are ho very clearly.All these composites reflect the large scale Of glacier, rapid movement of glacier. strongablation, develOPing of glacial lakes and subglacial channels and avalancheing of ice bodies, all which generally occour at warm or mattime glaciers.The glacial factes and glaciotectonic marks tespressent a martime (warm )glacial depositional process and thermal sitiuaion. The moraine plateform section is one of the most ideal field for research on glaciotectonice in China.