The Huguangyan Maar Lake(HML)(21°9'N,110°17'E),situated on the Leizhou Peninsula in the southernmost of China's Mainland,is the deepest recent crater lake among the identified volcanic structures i...The Huguangyan Maar Lake(HML)(21°9'N,110°17'E),situated on the Leizhou Peninsula in the southernmost of China's Mainland,is the deepest recent crater lake among the identified volcanic structures in the Leiqiong Volcanic Field.The bi-lobate lake.展开更多
The major and trace elements in 110 surface sediment samples collected from the middle of the Bay of Bengal(mid-Bay of Bengal) are analyzed to investigate provenance. Si levels are highest, followed by Al, and the d...The major and trace elements in 110 surface sediment samples collected from the middle of the Bay of Bengal(mid-Bay of Bengal) are analyzed to investigate provenance. Si levels are highest, followed by Al, and the distributions of these two elements are identical. The average CIA*(chemical index of alteration) value is 72.07,indicating that the degree of weathering of the sediments in the study area is intermediate between those of sediments of the Himalayan and Indian rivers. Factor analyses and discrimination function analyses imply that the two main provenances are the Himalayan and the Indian continent. The inverse model calculation of the Tinormalized element ratios of the Bay of Bengal sediments indicate an estimated average contribution of 83.5%and 16.5% from the Himalayan and peninsular Indian rivers to the study area, respectively. The Himalayan source contributes more sediment to the eastern part of the study area, whereas the western part receives more sediment from the Indian Peninsula than did the eastern part. The primary mechanisms for deposition of sediments in the study area are the transport of Himalayan matter by turbidity currents and river-diluted water and the transport of Indian matter to the study area by a surface circulation in the Bay of Bengal, particularly the East India Coastal Current.展开更多
The Yangtze River is one of the most important components of the East Asia river system. In this study, sediments in the Jianghan Basin, middle Yangtze River, were selected for trace element and rare earth element (...The Yangtze River is one of the most important components of the East Asia river system. In this study, sediments in the Jianghan Basin, middle Yangtze River, were selected for trace element and rare earth element (REE) measurements, in order to decipher information on the change of sediment provenance and evolution of the Yangtze River. According to the elemental variations, the late Cenozoic sediments of the Jianghan Basin could be divided into four parts. During 2.68-2,28 Ma and 1.25-0 Ma, proveJ nance of the sediments was consistent, whereas sediments were derived from variable sources during 2.28-1.25 Ma. Comparison of the elemental compositions between the Pliocene and Quaternary sediments revealed a change in sediment source from a more felsic source area to a more basic source area around the Pliocene--Quaternary boundary. Input from the Emeishan LIP should account for this provenance change, Based on the provenance analysis of sediments in the Jianghan Basin, we infer that the Yangtze River developed into a large river with its drainage basin extended to the Emeishan LIP no later than the Pliocene-Quaternary boundary.展开更多
基金financially supported by the China Geological Survey(grant no.1212011120045)the NSFC(grant no.41274074)
文摘The Huguangyan Maar Lake(HML)(21°9'N,110°17'E),situated on the Leizhou Peninsula in the southernmost of China's Mainland,is the deepest recent crater lake among the identified volcanic structures in the Leiqiong Volcanic Field.The bi-lobate lake.
基金The National Natural Science Foundation of China under contract No.U1606401the National Program on Global Change and Air-Sea Interaction of China under contract Nos GASI-02-IND-CJ02,GASI-GEOGE-03 and GASI-GEOGE-06-03
文摘The major and trace elements in 110 surface sediment samples collected from the middle of the Bay of Bengal(mid-Bay of Bengal) are analyzed to investigate provenance. Si levels are highest, followed by Al, and the distributions of these two elements are identical. The average CIA*(chemical index of alteration) value is 72.07,indicating that the degree of weathering of the sediments in the study area is intermediate between those of sediments of the Himalayan and Indian rivers. Factor analyses and discrimination function analyses imply that the two main provenances are the Himalayan and the Indian continent. The inverse model calculation of the Tinormalized element ratios of the Bay of Bengal sediments indicate an estimated average contribution of 83.5%and 16.5% from the Himalayan and peninsular Indian rivers to the study area, respectively. The Himalayan source contributes more sediment to the eastern part of the study area, whereas the western part receives more sediment from the Indian Peninsula than did the eastern part. The primary mechanisms for deposition of sediments in the study area are the transport of Himalayan matter by turbidity currents and river-diluted water and the transport of Indian matter to the study area by a surface circulation in the Bay of Bengal, particularly the East India Coastal Current.
基金supported by the National Natural Science Foundation of China(Grants Nos.40971008 and 40771213)the Open Research Program of State Key Laboratory of Loess and Quaternary Geology(Grant No.SKLLQG0908)
文摘The Yangtze River is one of the most important components of the East Asia river system. In this study, sediments in the Jianghan Basin, middle Yangtze River, were selected for trace element and rare earth element (REE) measurements, in order to decipher information on the change of sediment provenance and evolution of the Yangtze River. According to the elemental variations, the late Cenozoic sediments of the Jianghan Basin could be divided into four parts. During 2.68-2,28 Ma and 1.25-0 Ma, proveJ nance of the sediments was consistent, whereas sediments were derived from variable sources during 2.28-1.25 Ma. Comparison of the elemental compositions between the Pliocene and Quaternary sediments revealed a change in sediment source from a more felsic source area to a more basic source area around the Pliocene--Quaternary boundary. Input from the Emeishan LIP should account for this provenance change, Based on the provenance analysis of sediments in the Jianghan Basin, we infer that the Yangtze River developed into a large river with its drainage basin extended to the Emeishan LIP no later than the Pliocene-Quaternary boundary.