The Kumtag Desert is located in the arid northwestern portion of China,and is considered China’s sixth-largest desert.Grain-size analysis of the sand plays a very important role in differentiating sedimentary environ...The Kumtag Desert is located in the arid northwestern portion of China,and is considered China’s sixth-largest desert.Grain-size analysis of the sand plays a very important role in differentiating sedimentary environments,determining the ways that sediments are transported,estimating hydrodynamic conditions,and analyzing grain-size trends.The analysis of the grain size of 20 sand samples that were taken from mid-northern,north margin,western,middle,southern,and southeast margins of the Kumtag Desert shows that grain sizes are vastly different.The grain-size parameters fall in the following range:the median diameter Mz = 1.55Φ-2.92Φ,the standard deviation σI= 0.41-1.11,the skewness SKI = ?0.11-0.31,kurtosis KG = 0.77-1.23.The frequency curves of grain size have characteristics with single peaks and multi-peaks,and most of the sand samples’ skewness appears close to asymmetric.The analytical results reveal that the sediments of the Kumtag Desert are complex and diverse,which affected by such forces as wind deposition,lacustrine sediment,and alluvial and proluvial river deposits.展开更多
The Kumtag Desert, the fourth largest sand desert covered mainly by mobile dunes and shifting sands, had remained as the last untouched natural desert to be fully investigated in a scientific way. Therefore,＂Integrat...The Kumtag Desert, the fourth largest sand desert covered mainly by mobile dunes and shifting sands, had remained as the last untouched natural desert to be fully investigated in a scientific way. Therefore,＂Integrated Scientific Expedition of the Kumtag Desert Programme＂was listed as one of nine key research programmes of China National Science and Technology Basic Research Programmes in December, 2006. The expedition team carried out two large-scale and multidisciplinary scientific expeditions from June 2007 to December 2009, to the Kumtag Desert and collected more than 20 sets of field samples and ground observations. Finally, the expedition team completed not only systematic and integrated scientific expedition of the Kumtag Desert and filled in the gap of the last unexplored desert in China, but also gained fruitful research results in many scientific research subjects. These research results included that：（i） A unique aeolian landform unit, sand-gravel-moraine, developed in the Kumtag Desert, was defined and named for the first time, and the morphologic characteristics of feather-like longitudinal sand dune and its formation process are initially proved;（ii） Two sources and mineral element composition of the surface sedimentation of the Kumtag Desert was determined, and the characteristics of the desert sedimentation and stratum chronology of the Later Cenozoic Era was illustrated;（iii） The chronology of the paleo-aeolian sand was essentially determined and the formation courses and evolution process of the desert was illustrated;（iv） The thorough investigations of water system distribution, hydrology,chemical characteristics of water of the Kumtag Desert were made and six Water System Evolution Maps of the Kumtag Desert were compiled from the Later Cenozoic Era to the contemporary age;（v） The types, formation processes and distribution of soil in the Kumtag Desert were fully determined;（vi）An all-direction, all-weather, full-coverage desert meteorology observation was established and the characteristics and trend of climate change of the Kumtag Desert and nearby districts were adequately illustrated;（vii） It is the first time that the distribution areas of six plant species, including Tamarix taklamakanensis, Tamarix albiflonum, Agriophyllum lateriflorum etc., were catalogued in the Desert;（viii） The varieties, population, quantity and distribution of the wild animal such as the Bactrian Camel （Camelus ferus Przewalski）, are now documented;And （ix） it is the first time that the ecological services and economic function subdivision zones of the Kumtag Desert were classified;the Framework of the Great Dunhuang Special Ecological-Economic Zone was proposed to realize the sustainable development strategy in population, resources, environment, ecology and economics in the Kumtag Desert and nearby districts.展开更多
基金supported and assisted by the National Science and Technology Infrastructure Program (2006FY110800)the National Natural Science Foundation Project (40775019)+1 种基金the National Scientific Support Planning Subject (2008BAC40B05-01)the XinJiang Uighur Autonomous Region Science and Technology Key Projects (200833119)
文摘The Kumtag Desert is located in the arid northwestern portion of China,and is considered China’s sixth-largest desert.Grain-size analysis of the sand plays a very important role in differentiating sedimentary environments,determining the ways that sediments are transported,estimating hydrodynamic conditions,and analyzing grain-size trends.The analysis of the grain size of 20 sand samples that were taken from mid-northern,north margin,western,middle,southern,and southeast margins of the Kumtag Desert shows that grain sizes are vastly different.The grain-size parameters fall in the following range:the median diameter Mz = 1.55Φ-2.92Φ,the standard deviation σI= 0.41-1.11,the skewness SKI = ?0.11-0.31,kurtosis KG = 0.77-1.23.The frequency curves of grain size have characteristics with single peaks and multi-peaks,and most of the sand samples’ skewness appears close to asymmetric.The analytical results reveal that the sediments of the Kumtag Desert are complex and diverse,which affected by such forces as wind deposition,lacustrine sediment,and alluvial and proluvial river deposits.
基金China National Science and Technology Infrastructure Programme(2006FY110800)Academician Consulting Project of Chinese Academy of SciencesCentral Public-interest Scientific Institution Basal Research Fund(CAFYBB2010001-03)
文摘The Kumtag Desert, the fourth largest sand desert covered mainly by mobile dunes and shifting sands, had remained as the last untouched natural desert to be fully investigated in a scientific way. Therefore,＂Integrated Scientific Expedition of the Kumtag Desert Programme＂was listed as one of nine key research programmes of China National Science and Technology Basic Research Programmes in December, 2006. The expedition team carried out two large-scale and multidisciplinary scientific expeditions from June 2007 to December 2009, to the Kumtag Desert and collected more than 20 sets of field samples and ground observations. Finally, the expedition team completed not only systematic and integrated scientific expedition of the Kumtag Desert and filled in the gap of the last unexplored desert in China, but also gained fruitful research results in many scientific research subjects. These research results included that：（i） A unique aeolian landform unit, sand-gravel-moraine, developed in the Kumtag Desert, was defined and named for the first time, and the morphologic characteristics of feather-like longitudinal sand dune and its formation process are initially proved;（ii） Two sources and mineral element composition of the surface sedimentation of the Kumtag Desert was determined, and the characteristics of the desert sedimentation and stratum chronology of the Later Cenozoic Era was illustrated;（iii） The chronology of the paleo-aeolian sand was essentially determined and the formation courses and evolution process of the desert was illustrated;（iv） The thorough investigations of water system distribution, hydrology,chemical characteristics of water of the Kumtag Desert were made and six Water System Evolution Maps of the Kumtag Desert were compiled from the Later Cenozoic Era to the contemporary age;（v） The types, formation processes and distribution of soil in the Kumtag Desert were fully determined;（vi）An all-direction, all-weather, full-coverage desert meteorology observation was established and the characteristics and trend of climate change of the Kumtag Desert and nearby districts were adequately illustrated;（vii） It is the first time that the distribution areas of six plant species, including Tamarix taklamakanensis, Tamarix albiflonum, Agriophyllum lateriflorum etc., were catalogued in the Desert;（viii） The varieties, population, quantity and distribution of the wild animal such as the Bactrian Camel （Camelus ferus Przewalski）, are now documented;And （ix） it is the first time that the ecological services and economic function subdivision zones of the Kumtag Desert were classified;the Framework of the Great Dunhuang Special Ecological-Economic Zone was proposed to realize the sustainable development strategy in population, resources, environment, ecology and economics in the Kumtag Desert and nearby districts.
