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116 results on '"Dou, Yanguang"'

31. Historical trends of trace metals in muddy deposit along the Zhejiang coast, East China Sea: response to economic development and hypoxia

Author

Lilei Chen, Jian Liu, Gang Xu, Dou Yanguang, and Jiandong Qiu

Subjects
China, Geologic Sediments, Economic growth, 010504 meteorology & atmospheric sciences, Health, Toxicology and Mutagenesis, Drainage basin, 010501 environmental sciences, 01 natural sciences, Rivers, Metals, Heavy, Humans, Environmental Chemistry, Water pollution, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Terrigenous sediment, Hypoxia (environmental), Estuary, General Medicine, Pollution, Oceanography, Environmental science, Economic Development, Water quality, Enrichment factor, Water Pollutants, Chemical, Environmental Monitoring
Abstract

One sediment core spanning approximately 138 years was taken from the muddy deposits along the Zhejiang coast of the East China Sea, which is located in a hypoxic zone south of the Yangtze River estuary. When the sources of the trace metals in the core were analyzed, the three geochemical sources were identified as lithogenic, anthropogenic, and reductive deposits based on both principal component analysis and the ratios of terrigenous elements. The temporal distribution of the enrichment factor of copper in the sediment core matches the timeline of economic development and national policy in China. The rapid increase in human activity and economic development in the Yangtze River catchment accounts for the enrichment of copper in the sediment core. Based on the vertical distribution of arsenic concentration, the hypoxic zone south of the Yangtze River estuary may have not only existed, but worsened since 1875.

Published
2017

34. GEOCHEMISTRY OF MAJOR ELEMENTS IN THE SURFACE SEDIMENTS OF THE OFFSHORE AREA OF SHANDONG PENINSULA AND ITS GEOLOGICAL IMPLICATIONS

Author

Yang Min, Dou Yanguang, Hu Bangqi, Li Guogang, Jun Li, and Bu Ruyuan

Subjects
Total organic carbon, Terrigenous sediment, Group (stratigraphy), Geochemistry, Sediment, Submarine pipeline, Weathering, Authigenic, Shandong peninsula, Geology
Abstract

In this study,a total of 274 surface sediments from the offshore area of Shandong Peninsula were collected and analyzed for grain-size,total organic carbon(TOC),and major elementss.Results show that SiO2 is the highest major element,followed by Al2O3 as the second.These two major elements make up 77.8% of the total major elements.The composition of major elements depends upon the type of sediment or grain-size.SiO2 is usually enriched in the coarse-grained sediments,whereas Al2O3、Fe2O3、MgO、MnO、P2O5 and K2O are relatively concentrated in fine-grained sediments.However,Na2O and TiO2 are independent from sediment types.The results of correlation and R-factor analysis suggested that the distribution of major element in the surface sediments from the offshore area of Shandong Peninsula can be classified to three groups.The first group consists of SiO2、Al2O3、Fe2O3、MgO、K2O、TiO2、P2O5、TOC,the second includes CaO and CaCO3,and Na2O and MnO belong to the last groups.These three groups may probably represent terrigenous,marine biogenous and marine authigenic sediments respectively.The chemical weathering index of the surface sediments varies from 50-65,depending upon their provenance.The CIA and TiO2/Al2O3 values suggest that the Huanghe sediments are mainly deposited along the offshore area of Shandong Peninsula,controlled by the coastal currents and the sea bottom geomorphology.

Published
2013

40. Prehistoric heavy metal pollution on the continental shelf off Hainan Island, South China Sea: From natural to anthropogenic impacts around 4.0 kyr BP.

Author

Xu, Fangjian, Hu, Bangqi, Dou, Yanguang, Song, Zhaojun, Liu, Xiting, Yuan, Shengqiang, Sun, Zhilei, Li, Anchun, and Yin, Xuebo

Subjects
HEAVY metals & the environment, CONTINENTAL shelf, GEOCHEMISTRY, SEDIMENTS
Abstract

Human–environment interactions across historical periods in China have been well reconstructed over the past decade; however, few studies have focused on southern China, particularly Hainan Island. This study investigated two sediment cores (cores X1 and X2) collected from the continental shelf off Hainan Island in the northern South China Sea. Combined with geochemical compositions (Al, Ni, Cu, Zn, Cd, and Pb), Sr-Nd isotopes, grain size, and AMS 14C ages, our results showed that Cd and Cu in core X1 and Cd and Pb in core X2 have been mainly influenced by anthropogenic activities since ~4.0 kyr BP. The enrichment factors showed obvious increases starting at ~4.0 kyr BP and were in good accordance with the appearance of abundant archeological sites on Hainan Island. Significant climatic changes (i.e. decreases in the East Asian summer monsoon and increases in El Niño–Southern Oscillation activities) at ~4.0 kyr BP likely promoted more intense, localized human activities, which in turn enhanced heavy metal accumulation in the continental shelf sediments. These results provide new insights into the history of human activities on Hainan Island and indicate that the geochemical compositions of continental shelf sediments have the potential for broadening our knowledge of the human activities and cultural development in tropical areas. [ABSTRACT FROM AUTHOR]

Published
2018
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