以米浪沟湾地层剖面作为萨拉乌苏河流域的典型剖面,探讨了150 ka B.P.以来的CaCO3含量分布与气候变化的关系。1)该剖面CaCO3含量及其低-高变化同古风成沙与上覆河湖相或古土壤构成的沉积旋回呈现出明显的对应关系。与米浪沟湾剖面的沉...以米浪沟湾地层剖面作为萨拉乌苏河流域的典型剖面,探讨了150 ka B.P.以来的CaCO3含量分布与气候变化的关系。1)该剖面CaCO3含量及其低-高变化同古风成沙与上覆河湖相或古土壤构成的沉积旋回呈现出明显的对应关系。与米浪沟湾剖面的沉积旋回一样,CaCO3在分布上相应地构成了27个含量高低变化旋回。2)CaCO3在风成沙中含量的分布比较稀散,0.8%~7.18%,平均值2.50%;在河湖相和古土壤中相对富集,2.20%~14.90%。平均值5.74%。从而揭示出其时两者的气候背景是不同的,前者是干旱寒冷气候作用下的风力的侵蚀、搬运与堆积的产物;而后者则与暖湿气候环境下萨拉乌苏河流域地处鄂尔多斯高原和黄土高原之间特殊的低洼地貌位置有关。气候暖湿,河湖沼泽发育、成土成壤作用增强,低洼的集水条件有利于CaCO3的聚集。3)导致米浪沟湾剖面CaCO3的多旋回相对稀散与聚集的根本原因可能是150 ka B.P.以来北半球冰期-间冰期气候波动影响下毛乌素沙漠冬夏季风的多次更迭所致。展开更多
The paper makes some analyses on 11 trace elements in the Milanggouwan stratigraphical section in the Salawusu River valley, which is regarded as a prototype geology-palaeoclimate record since 150 ka BP. The results s...The paper makes some analyses on 11 trace elements in the Milanggouwan stratigraphical section in the Salawusu River valley, which is regarded as a prototype geology-palaeoclimate record since 150 ka BP. The results show that the content and variation of trace elements has experienced remarkably regular changes in the pace with coarse and fine sedimentary cycles of palaeo-aeolian sands to its overlying fluvio-lacustrine facies or/and palaeosols. The trace elements with chemical properties of relatively active (V, Sr, Cu, Ni, As) and relatively stable (P, Pb, Rb, Mn, Nb, Zr) are a manifestation of the corresponding 27 changeable cycles between peak and valley values, appearing a multi-fiuctuational process line of relative gathering and migration since then. The low numerical value distribution of these two types of trace elements in the aeolian sand facies represents erosion and accumulation under wind force during the cold-dry climate. Whereas their enrichments in both fluvio-lacustrine facies and palaeosols are related to the valley’s special low-lying physiognomic position between the Ordos Plateau and the Loess Plateau under the warm and humid climate conditions. The above relatively migrated and gathered change of the trace elements is the result of 27 climatic cycles of cold-dry and warm-humid, which is probably caused by repeated alternations of winter monsoon and summer monsoon in the Mu Us Sandy Land influenced by the climate vicissitudes in northern hemisphere during glacial and interglacial periods since 150 ka BP.展开更多
The palaeo-mobile dune sands and fluvio-lacustrine facies with palaeosols in Milanggouwan stratigraphic section of the Salawusu River valley situated at the southeast of the Mu Us Desert experienced abundant remarkabl...The palaeo-mobile dune sands and fluvio-lacustrine facies with palaeosols in Milanggouwan stratigraphic section of the Salawusu River valley situated at the southeast of the Mu Us Desert experienced abundant remarkable alternative changes of coarse and fine rhythms in grain-size since 150 ka BP, and the grain-size parameters Mz,σ, Sk, Kg and SC/D also respond to the situation of multi-fluctuational alternations between peak and valley values. Simultaneity the grain-size eigenvalues F5, F16, F25, F50, F75, F84 and F95 are respondingly manifested as greatly cadent jumpiness. Hereby, the Milanggouwan section can be divided into 27 grain-size coarse and fine sedimentary cycles, which can be regarded as a real and integreted record of climate-geological process of desert vicissitude resulted from the alternative evolvement of the ancient winter and summer monsoons of East Asia since 150 ka BP.展开更多
Milanggouwan stratigraphical section" named lately takes down 27 cycles of alternately evolutionary histories of desert depositions in the Mu Us area with the fluviolacustrine facies and palaeosols since 150 ka B...Milanggouwan stratigraphical section" named lately takes down 27 cycles of alternately evolutionary histories of desert depositions in the Mu Us area with the fluviolacustrine facies and palaeosols since 150 ka B.P. Studies show that the sedimentary form was induced by the growth and decline and confrontation each other between the winter monsoon and the summer monsoon of East Asia in the past 150 ka.展开更多
ABSTRACT: This paper, with Milanggouwan stratigraphic section as a typical section of the Salawusu River Basin, explores the relation between CaCO3 content distribution and climate change since 150 ka B. P. and conclu...ABSTRACT: This paper, with Milanggouwan stratigraphic section as a typical section of the Salawusu River Basin, explores the relation between CaCO3 content distribution and climate change since 150 ka B. P. and concludes that: 1) The low-high changes of CaCO3 content in the section has a remarkable corresponding relation with the sedimentary cycles of ancient aeolian sand and overlying fluviolacustrine facies or palaeosols. 2) CaCO3 distribution in aeolian sand is relatively meagre, ranging from 0. 8% - 7. 18%, or on an average 2. 50% but relatively enriches in the fluviolacustrine faceis and palaeosols, ranging from 2. 20% - 14. 9% , or on an average 5. 74%. This implies that they have different climatic backgrounds. The former was the product of erosion, transport and deposition by wind under arid and cold climatic conditions, whereas the latter was related to its special low-lying geomorphic position between the Ordos Plateau and Loess Plateau and warm-humid climatic environment. When the climatic became warm and humid, fluviolacustrine and swamp facies developed, soil-forming action strengthened, and low-lying catchment condition was favorable to CaCO3 accumulation. 3) The basic cause responsible for the multicycle of CaCO3 migration and accumulation in the Milanggouwan section may be the multiple alterations of winter and summer monsoons over the Mu Us Desert under the influences of climatic fluctuation of glacial and interglacial periods in the Northern Hemisphere since 150ka B. P. .展开更多
According to the bioclimatic zones, dune mobility and the fabric characteristics of stratigraphic sedimentary facies, the deserts in China are divided into Eastern, Western, Central and Northwestern deserts. Based on ...According to the bioclimatic zones, dune mobility and the fabric characteristics of stratigraphic sedimentary facies, the deserts in China are divided into Eastern, Western, Central and Northwestern deserts. Based on the records of stratigraphical facies, climatic proxies, historical data, etc. in each desert region, the evolution of deserts with climatic changes in time and space since 150 ka B. P. in China are dealt with; then the evolution of deserts in relation to the glacial climatic fluctuations caused by solar radiation changes, underlying surface variation and their feedback mechanism is discussed through comparison with global records; finally, in consideration of global wanning due to increasing of greenhouse gases such as CO2, the possible tendency of the evolution of deserts and the climatic changes is discussed.展开更多
文摘以米浪沟湾地层剖面作为萨拉乌苏河流域的典型剖面,探讨了150 ka B.P.以来的CaCO3含量分布与气候变化的关系。1)该剖面CaCO3含量及其低-高变化同古风成沙与上覆河湖相或古土壤构成的沉积旋回呈现出明显的对应关系。与米浪沟湾剖面的沉积旋回一样,CaCO3在分布上相应地构成了27个含量高低变化旋回。2)CaCO3在风成沙中含量的分布比较稀散,0.8%~7.18%,平均值2.50%;在河湖相和古土壤中相对富集,2.20%~14.90%。平均值5.74%。从而揭示出其时两者的气候背景是不同的,前者是干旱寒冷气候作用下的风力的侵蚀、搬运与堆积的产物;而后者则与暖湿气候环境下萨拉乌苏河流域地处鄂尔多斯高原和黄土高原之间特殊的低洼地貌位置有关。气候暖湿,河湖沼泽发育、成土成壤作用增强,低洼的集水条件有利于CaCO3的聚集。3)导致米浪沟湾剖面CaCO3的多旋回相对稀散与聚集的根本原因可能是150 ka B.P.以来北半球冰期-间冰期气候波动影响下毛乌素沙漠冬夏季风的多次更迭所致。
基金National Natural Science Foundation of China, No. 49971009State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment, CAS, No. SKLLQG0008+1 种基金National Key Project for Basic Research No. G2000048701
文摘The paper makes some analyses on 11 trace elements in the Milanggouwan stratigraphical section in the Salawusu River valley, which is regarded as a prototype geology-palaeoclimate record since 150 ka BP. The results show that the content and variation of trace elements has experienced remarkably regular changes in the pace with coarse and fine sedimentary cycles of palaeo-aeolian sands to its overlying fluvio-lacustrine facies or/and palaeosols. The trace elements with chemical properties of relatively active (V, Sr, Cu, Ni, As) and relatively stable (P, Pb, Rb, Mn, Nb, Zr) are a manifestation of the corresponding 27 changeable cycles between peak and valley values, appearing a multi-fiuctuational process line of relative gathering and migration since then. The low numerical value distribution of these two types of trace elements in the aeolian sand facies represents erosion and accumulation under wind force during the cold-dry climate. Whereas their enrichments in both fluvio-lacustrine facies and palaeosols are related to the valley’s special low-lying physiognomic position between the Ordos Plateau and the Loess Plateau under the warm and humid climate conditions. The above relatively migrated and gathered change of the trace elements is the result of 27 climatic cycles of cold-dry and warm-humid, which is probably caused by repeated alternations of winter monsoon and summer monsoon in the Mu Us Sandy Land influenced by the climate vicissitudes in northern hemisphere during glacial and interglacial periods since 150 ka BP.
基金National Natural Science Foundation of China No. 49971009+5 种基金 State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment CAS No. SKLLQG0008 The Key National Project for Basic Research No. G2000048701
文摘The palaeo-mobile dune sands and fluvio-lacustrine facies with palaeosols in Milanggouwan stratigraphic section of the Salawusu River valley situated at the southeast of the Mu Us Desert experienced abundant remarkable alternative changes of coarse and fine rhythms in grain-size since 150 ka BP, and the grain-size parameters Mz,σ, Sk, Kg and SC/D also respond to the situation of multi-fluctuational alternations between peak and valley values. Simultaneity the grain-size eigenvalues F5, F16, F25, F50, F75, F84 and F95 are respondingly manifested as greatly cadent jumpiness. Hereby, the Milanggouwan section can be divided into 27 grain-size coarse and fine sedimentary cycles, which can be regarded as a real and integreted record of climate-geological process of desert vicissitude resulted from the alternative evolvement of the ancient winter and summer monsoons of East Asia since 150 ka BP.
文摘Milanggouwan stratigraphical section" named lately takes down 27 cycles of alternately evolutionary histories of desert depositions in the Mu Us area with the fluviolacustrine facies and palaeosols since 150 ka B.P. Studies show that the sedimentary form was induced by the growth and decline and confrontation each other between the winter monsoon and the summer monsoon of East Asia in the past 150 ka.
基金Under the auspices of the National Natural Science Foundation of China(No.49971009) State Key Laboratory ofLoess and Quaternary Geology,Institute of Earth Environment,the Chinese Academy of sciences(SKLLQG0088)and National KeyProject for Basic Re
文摘ABSTRACT: This paper, with Milanggouwan stratigraphic section as a typical section of the Salawusu River Basin, explores the relation between CaCO3 content distribution and climate change since 150 ka B. P. and concludes that: 1) The low-high changes of CaCO3 content in the section has a remarkable corresponding relation with the sedimentary cycles of ancient aeolian sand and overlying fluviolacustrine facies or palaeosols. 2) CaCO3 distribution in aeolian sand is relatively meagre, ranging from 0. 8% - 7. 18%, or on an average 2. 50% but relatively enriches in the fluviolacustrine faceis and palaeosols, ranging from 2. 20% - 14. 9% , or on an average 5. 74%. This implies that they have different climatic backgrounds. The former was the product of erosion, transport and deposition by wind under arid and cold climatic conditions, whereas the latter was related to its special low-lying geomorphic position between the Ordos Plateau and Loess Plateau and warm-humid climatic environment. When the climatic became warm and humid, fluviolacustrine and swamp facies developed, soil-forming action strengthened, and low-lying catchment condition was favorable to CaCO3 accumulation. 3) The basic cause responsible for the multicycle of CaCO3 migration and accumulation in the Milanggouwan section may be the multiple alterations of winter and summer monsoons over the Mu Us Desert under the influences of climatic fluctuation of glacial and interglacial periods in the Northern Hemisphere since 150ka B. P. .
文摘According to the bioclimatic zones, dune mobility and the fabric characteristics of stratigraphic sedimentary facies, the deserts in China are divided into Eastern, Western, Central and Northwestern deserts. Based on the records of stratigraphical facies, climatic proxies, historical data, etc. in each desert region, the evolution of deserts with climatic changes in time and space since 150 ka B. P. in China are dealt with; then the evolution of deserts in relation to the glacial climatic fluctuations caused by solar radiation changes, underlying surface variation and their feedback mechanism is discussed through comparison with global records; finally, in consideration of global wanning due to increasing of greenhouse gases such as CO2, the possible tendency of the evolution of deserts and the climatic changes is discussed.