To predict the soil-water characteristic curve(i.e.SWCC)of natural and remoulded Malan loess from soil physical properties,one-point methods for determining the SWCC that are much simpler than experimental methods are...To predict the soil-water characteristic curve(i.e.SWCC)of natural and remoulded Malan loess from soil physical properties,one-point methods for determining the SWCC that are much simpler than experimental methods are proposed.The predicted SWCC is presented in the form of the BRUTSAERT equation,in which the four model parameters can be estimated from soil physical properties using the best correlations obtained in the present study along with one measured data point.The proposed one-point methods are validated using the measured SWCC data reported in the literature.The results of validation studies suggest that the proposed one-point methods can provide reasonable prediction of the SWCC for natural and remoulded Malan loess.The measured data point should be within the transition zone;the measured suction is suggested between25to100kPa for natural loess,while between100to500kPa for remoulded loess.展开更多
The platforms on both sides of the Malangou River （a lateral ditch of the Qingshui River that is a tributary of the Yongding River） where Malan Village in Zhaitang Town of Mentougou District of Beijing is located ar...The platforms on both sides of the Malangou River （a lateral ditch of the Qingshui River that is a tributary of the Yongding River） where Malan Village in Zhaitang Town of Mentougou District of Beijing is located are the place of China＇s typical section of the Quaternary Malan loess. During the investigation in the eastern suburbs of Beijing City, the authors not only clarified 5 grades of terraces on the Pinggu piedmont plain, but also found a clayey silt section mixed with a small amount of alluvial-diluvial gravel layers at a height of 15-25 m above the river level near a Fishpond in Xinli Village of Nandule Town. Results of the study of grain size of the section document that the loess mostly is silty soil （0.05--0.005 mm）, and that the grain size probability cumulative curves of the section are dominated by single-peak, coarse-grained segment I and coarse-grained segment II types, reflecting that its depositional environment is similar to eolian phase. Identification results of heavy minerals from the section show that their contents account for 0.01%-0.11%, averaging 0.04%. There are 24 kinds of heavy minerals, most of which are stable heavy minerals, and the clay minerals mostly are illite, which is consistent with the Malan loess on the Loess Plateau. The chemical composition data reflect that the source area of the loess is relatively arid. The six grade classification of sporopollen in the section further shows the subdivision of the history of alternating warm and humid phases in this geological period. The thermoluminescence dating results range from 21.0 ka to 59.2 ka, convincingly demonstrating that the section indeed consists of Malan loess. The above studies provide a new basis for overall understanding of the distribution of the Malan loess at the northeast margin of the North China Plain and its environment change in the Late Pleistocene.展开更多
Loess has unique compositions and structural characteristics and can be used for environmental protection.Differences between the surface characteristics of the Malan loess from the suburbs of Taiyuan,Shanxi Province ...Loess has unique compositions and structural characteristics and can be used for environmental protection.Differences between the surface characteristics of the Malan loess from the suburbs of Taiyuan,Shanxi Province before and after reaction with Cr(Ⅲ) solution were studied by SEM/EDS,IR and XRD.The results showed that the Malan loess has a strong ability to remove Cr(Ⅲ) from the solution.The surface characteristics of loess include an effect on Cr(Ⅲ) in solution,as supported by the strong test evidence including the disappearance of Cr peak in the EDS spectrum,the disappearance of carbonate characteristic peaks in the infrared spectrogram,and the positive correlation between Fe and Cr peaks.展开更多
Loess of China, especially the Malan loess distributed along the middle reaches of the Huanghe River, has attracted great attention of many geologists throughout the world because of its extensive occurrence and close...Loess of China, especially the Malan loess distributed along the middle reaches of the Huanghe River, has attracted great attention of many geologists throughout the world because of its extensive occurrence and close relation with the living environment of mankind. As the Malan loess was formed relatively late, and thus has not been affected by hysterogenic diagenesis, it has well preserved the primary characteristics at the time of展开更多
A preliminary study of the Malan loess on the eastern margin of the Qinghai-Xizang(Tibetan)Plateau and its adjacent area shows that along the boundary of Kunlun Mts.-Buqing Mts.-A’nymaqnMts.-South Qinling(Motianling)...A preliminary study of the Malan loess on the eastern margin of the Qinghai-Xizang(Tibetan)Plateau and its adjacent area shows that along the boundary of Kunlun Mts.-Buqing Mts.-A’nymaqnMts.-South Qinling(Motianling),the Malun loess falls roughly into two main depositional regions:to itsnorth,a hot loess region in which dusts come mainly from the Asian inland arid area;to its south,a coldloess region in which dusts come chiefly from the Qinghai-Xizang Plateau.The possible causative fac-tors and processes for the loess difference are the uplift of the Plateau and the effects of its resultant particuolar landform,the interactions of its induced Asian monsoon,by-flowing westlies and plateau monsoon,and thedifference of sediments of source areas.展开更多
The Quaternary loess deposits in the arid-semiarid area in northwestern China are composed of eolian sedimemts which are continuous in terms of sedimentation and have undergone little alternation after deposition.They...The Quaternary loess deposits in the arid-semiarid area in northwestern China are composed of eolian sedimemts which are continuous in terms of sedimentation and have undergone little alternation after deposition.They provide an ideal place for the preservation of the extraterrestrial falls on the earth.The Late Pleistocene Malan loess is chosedn for our study of the preserved cosmic dusts.展开更多
基金Project(41372329) supported by the National Natural Science Foundation of ChinaProject(2014CB744701) supported by the National Basic Research Program of China
文摘To predict the soil-water characteristic curve(i.e.SWCC)of natural and remoulded Malan loess from soil physical properties,one-point methods for determining the SWCC that are much simpler than experimental methods are proposed.The predicted SWCC is presented in the form of the BRUTSAERT equation,in which the four model parameters can be estimated from soil physical properties using the best correlations obtained in the present study along with one measured data point.The proposed one-point methods are validated using the measured SWCC data reported in the literature.The results of validation studies suggest that the proposed one-point methods can provide reasonable prediction of the SWCC for natural and remoulded Malan loess.The measured data point should be within the transition zone;the measured suction is suggested between25to100kPa for natural loess,while between100to500kPa for remoulded loess.
基金funded by the project Ecological Agricultural Geological Survey and Demonstration Research of Xinli Village in Pinggu District, Beijing under the Central Research Institutes of Basic Research and Public Service Special Operations K1201 and the geological survey project (Grant No. 1212011300010)
文摘The platforms on both sides of the Malangou River （a lateral ditch of the Qingshui River that is a tributary of the Yongding River） where Malan Village in Zhaitang Town of Mentougou District of Beijing is located are the place of China＇s typical section of the Quaternary Malan loess. During the investigation in the eastern suburbs of Beijing City, the authors not only clarified 5 grades of terraces on the Pinggu piedmont plain, but also found a clayey silt section mixed with a small amount of alluvial-diluvial gravel layers at a height of 15-25 m above the river level near a Fishpond in Xinli Village of Nandule Town. Results of the study of grain size of the section document that the loess mostly is silty soil （0.05--0.005 mm）, and that the grain size probability cumulative curves of the section are dominated by single-peak, coarse-grained segment I and coarse-grained segment II types, reflecting that its depositional environment is similar to eolian phase. Identification results of heavy minerals from the section show that their contents account for 0.01%-0.11%, averaging 0.04%. There are 24 kinds of heavy minerals, most of which are stable heavy minerals, and the clay minerals mostly are illite, which is consistent with the Malan loess on the Loess Plateau. The chemical composition data reflect that the source area of the loess is relatively arid. The six grade classification of sporopollen in the section further shows the subdivision of the history of alternating warm and humid phases in this geological period. The thermoluminescence dating results range from 21.0 ka to 59.2 ka, convincingly demonstrating that the section indeed consists of Malan loess. The above studies provide a new basis for overall understanding of the distribution of the Malan loess at the northeast margin of the North China Plain and its environment change in the Late Pleistocene.
基金supported by the National Natural Science Foundation of China (Nos. 40402021 and 40830748)the China-Russia International Cooperation and Exchange Project of NSFC-RFBR (No. 40711120189)+4 种基金the Key Project of Chinese Ministry of Education (No. 104038)Program for New Century Excellent Talents in University (NCET-07-0773)the Aid Project of Science and Technology Ministry of China to Developing Countries (2008041012)National High Technology Research and Development Program 863 (2007AA06Z337)the Excellent Young Teachers Program of China University of Geosciences (CUGQNL0303)
文摘Loess has unique compositions and structural characteristics and can be used for environmental protection.Differences between the surface characteristics of the Malan loess from the suburbs of Taiyuan,Shanxi Province before and after reaction with Cr(Ⅲ) solution were studied by SEM/EDS,IR and XRD.The results showed that the Malan loess has a strong ability to remove Cr(Ⅲ) from the solution.The surface characteristics of loess include an effect on Cr(Ⅲ) in solution,as supported by the strong test evidence including the disappearance of Cr peak in the EDS spectrum,the disappearance of carbonate characteristic peaks in the infrared spectrogram,and the positive correlation between Fe and Cr peaks.
基金Project supported by the National Natural Science Foundation of China.
文摘Loess of China, especially the Malan loess distributed along the middle reaches of the Huanghe River, has attracted great attention of many geologists throughout the world because of its extensive occurrence and close relation with the living environment of mankind. As the Malan loess was formed relatively late, and thus has not been affected by hysterogenic diagenesis, it has well preserved the primary characteristics at the time of
基金the National Natural Science Foundation of Chinathe Fund for Returned Overseas Scholars' Starting Work
文摘A preliminary study of the Malan loess on the eastern margin of the Qinghai-Xizang(Tibetan)Plateau and its adjacent area shows that along the boundary of Kunlun Mts.-Buqing Mts.-A’nymaqnMts.-South Qinling(Motianling),the Malun loess falls roughly into two main depositional regions:to itsnorth,a hot loess region in which dusts come mainly from the Asian inland arid area;to its south,a coldloess region in which dusts come chiefly from the Qinghai-Xizang Plateau.The possible causative fac-tors and processes for the loess difference are the uplift of the Plateau and the effects of its resultant particuolar landform,the interactions of its induced Asian monsoon,by-flowing westlies and plateau monsoon,and thedifference of sediments of source areas.
基金Project supported by the Xi'an Lab of LoessQuaternary Geology.
文摘The Quaternary loess deposits in the arid-semiarid area in northwestern China are composed of eolian sedimemts which are continuous in terms of sedimentation and have undergone little alternation after deposition.They provide an ideal place for the preservation of the extraterrestrial falls on the earth.The Late Pleistocene Malan loess is chosedn for our study of the preserved cosmic dusts.
