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6411563 
Journal Article 
Formation mechanisms of megadunes and lakes in the Badain Jaran Desert, Inner Mongolia 
Chen Jiansheng; Zhao Xia; Sheng Xuefen; Dong Haizhou; Rao Wenbo; Su Zhiguo 
2006 
Yes 
Chinese Science Bulletin
ISSN: 1001-6538
EISSN: 1861-9541 
51 
24 
3026-3034 
WOS:000243990800013 
Field observations demonstrate that calc-sinters occurred in the lakes of Badain Jaran Desert. super(87)Sr/ super(86)Sr ratios, super(14)C, delta super(13)C and mineral compositions of calc-sinters, and super(3)He/ super(4)He, super(4)He/ super(20)Ne, delta super(18)O, delta D, pH and TDS of water from springs and lakes are analyzed in detail. The results indicate that the lake water is supplied through deep fault zone. The kernel of stabilized dunes in the Badain Jaran Desert perhaps consists of calc-sinters and calcareous cementation layers. Deep-seated groundwater effuses from this kernel and recharges to lakes in desert. Precipitation and snowmelt water from the Qing-hai-Tibet Plateau is fed into the Badain Jaran Desert, Gurinai, Wentougaole and Ejinqi areas through the Xigaze-Langshan Fault zone. The isotopic compositions of groundwater in the Alax Plateau are abnormal due to the strong evaporation of the Gyaring and Ngoring lake water in the headstream of the Yellow River. Groundwater dissolves dissoluble fractions of rocks during its transportation through the fault zone and flows out of the mouth of spring in the Badan Jaran Desert. The dissoluble fractions are finally developed into calc-sinters and calcareous cementation layers around the spring. Calci-sinters are gradually largened and eventually emerge on the surface of lake water. Eolian sands accumulate on the surfaces of calc-sinters and calcareous cementation layers, and eventually develop into dunes. Invasion of magma causes an increase in the temperature of groundwater within the faults. Groundwater evaporation provides water vapor for the formation of humid stabilized dunes during its upwelling. Rhizoconcretions found in Yihejigede indicate that the dune was formed and remained immovable 4700 years ago. The height of the megadunes is proportional to thermal quantity carried by the groundwater. 
Badain Jaran Desert; Xigaze-Langshan Fault zone; megadunes; calc-sinters; isotopic compositions