关键词: 塔克拉玛干沙漠, 沙垄, 沙丘形态, 纵向沙丘, 第四纪, 横向沙丘, 沙源, 塔里木盆地, 复合型沙丘链, 风成沙

Abstract: The distribution of land and sea, the violent rise of Qinghai-Xizang Plateau, thechange of the inclination of the axis of rotation of the Earth and the horizontal dis-placement of the structure caused the climate of the Tarim Basin, which is situateddeeply inland, to become very dry and the aridity has been further intensified sincethe Quaternary period. All the above mentioned factors provided favourable climaticconditions for the formation and development of desert. In the humid times of theQuaternary period, a great number of rivers fed by a great amount of melting snow, de-posited a thick and loose sand layer in the basin which became a rich source of sand inthe desert.The present dimension of the Taklamakan desert has been gradually developedsince the Middle Plesistocene period. As the dryness of the climate increased, the desertextended from the center of the basin to the periphery and from east to west.The topography of the tremendous intermountane basin of Tarim greatly in-fluenced the air current and was favourable to the development of transverse sanddunes. This types of sand dunes predominates the Taklamakan Desert. Longitudinalsand dunes were formed under the action of helical turbulent flow of the atmosphereand they were mainly distributed in the central part of the desert, where the aircurrent was not interfered, so that in the plain area of ancient delta, the wind direc-tion remained unchanged.