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JOURNAL OF DESERT RESEARCH ›› 2003, Vol. 23 ›› Issue (6): 703-708.

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The Formation of Proglacial Desert on the West of Icefield Puruogangri and Discovery of Glacial-Type Desert in China

LI Xiao-ze, YAO Tan-dong, QU Jian-jun, ZHANG Wei-min, DONG Guang-rong   

  1. Key Laboratory of Desert and Desertification, Cold and A rid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2002-05-28 Revised:2002-10-28 Online:2003-12-20 Published:2003-12-20

Abstract: There are about 100 km2 of aeolian landforms consisting of gobi and sand dunes on the piedmont surface of rock stream slope at west side of Puruogangri icefield in the center of the Qinghai-Tibet Plateau.This is one of the world s rare proglacial desert deposits and also the first example found in the mid-latitude and high-altitude region of China.Field observation,stratigraphic measurements,indoor sample analyses including particle size and minerals and 14C dating showed that they had been formed since 16 ka BP.Some of the most striking depositional features are that scattered humus layers are intercalated in the sand dune sedimentary sequence;on the surface of gobi gravel there are secondary calcite or CaCO3 precipitates.The desert exhibited a cold rectilinear evolutional pattern.It was formed with underling glacial tills as the main sand source,with the planet westerly circulation and west winds caused by the plateau s winter monsoon as the main driving forces,and with persistent cold and semiarid weather as the climatic background.In other words their origin is related to the abundant sand supply from glacial tills at the west side of the ice field.Such desert is quite different from the periglacial desert with fluviolacustrine deposits as sand source and therefore is called glacial-type desert.Since its origin is closely related to the changes of icefield,climate and atmospheric circulation,it provides important records of Holocene climate and environmental changes in the hinterland of the plateau.

Key words: Puruogangri ice field, proglacial aeolian sand landform, glacial-type desert, Holocene environment

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