关键词: 雅丹地貌, 分布, 特征, 形成时代, 玉门关

Abstract: The study area is located in the W-E fault valley 68 km west to Yumenguan, on a residual hill peneplain of the North Mountain north to Suleihe billabong (90°~90°10'E,40°30'~40°34'N). There, the paleo-lacustrine sediments composing Yardang landform is deposited in the period of Middle and even Early Pleistocene. Then the deposits were covered by Gobi gravel layer during the Late Pleistocene after the lake water retreating westward due to neotectonic movement in the Middle Pleistocene. There was a billabong with W-E trend developed in the end of Late Pleistocene, and then Yardangs formed in it resulted from strong N-wind from Mongolian Plateau. Here many with 20~40 m height generally, the highest Yardang reached about 100 m. These Yardangs are large-middle types, dense and with special shapes, which are scarce over the world. This place is one nice place for tourism, expedition and science research.

Key words: Yardang, distribution, characteristics, formation period, Yumenguan