REE of Sediments of the Changliushui Section at Zhongwei County of Ningxia Province and the Environmental Significance

Key words: 
• Late pleistocene margin of desert REE /
• climate environment /
• Ningxia province /
•  /

Abstract: Reported in this paper are the REE distribution patterns,character parameter and correlation coefficient between REE &primary elements in Quarternary sediments of Changliushui section developed at a depressed qully at Zhongwci County of Ningxia Rcgion, ncar the southcrn margin of the Ala Shant Desert in North－West China.The material source of the fluvo－lacustrine deposits and the evolutionary of the climate and the environment in the desert front area also discussed here in the section,there are three main climatic and environmental changes from dry and cool to warm and moist during deposition,and four or five secondary climatic fluctuations.At the depth of 2.7 m,the content of REE change very clearly.It seems a eflection of temperate period of Holocene in the area (9300～54300 a.B.P.).REE characters show that the source of the aeolian sans of the deposit area mainly came from surrounding parent rock material. Additionally,it also possible that the weathered material of Jurassic rock was brougt into the sedimentary series by washing.The chane of sedimentary facirs from aeolion to fluvial thcn to lacustinc origins synchronusly coincied with the changc of climate from dry－cold cold-moist to warm moist.The arid desert environment is dominant,in which the chemical and wethering processes are weak.