The relatively abundant palynomorphs were recovered from the samples of the first paleosol layer of core CY in Shanghai for the first time. A total of 55 genera and families of spore, pollen and phytoplankton were ide...The relatively abundant palynomorphs were recovered from the samples of the first paleosol layer of core CY in Shanghai for the first time. A total of 55 genera and families of spore, pollen and phytoplankton were identified. According to the characteristics of the palynological assemblages, the depositional conditions in the development period of the paleosols were discussed and the microfossil evidence to study the origin of the paleosols in the Yangtze Delta area was provided as well. The research results show that paleosols should be freshwater deposits. The palynological assemblage sequence in the first paleosol layer reveals fluctuations of freshwater palynomorphs, mainly Concentricystis, and terricolous herbs pollen, reflecting the alternations of deposition and exposure in the development period of the paleosols. Concentricystis developed prosperously in the period of flood, while terricolous herbs grew on the emerged land in the period of exposure. The variations in the palynological展开更多
Rare earth element (REE) compositions of the suspended sediments from the rivers around the Yellow Sea were different in that Korean river sediments (Han, Keum and Yeongsan Rivers) yield stronger fractionations than C...Rare earth element (REE) compositions of the suspended sediments from the rivers around the Yellow Sea were different in that Korean river sediments (Han, Keum and Yeongsan Rivers) yield stronger fractionations than Chinese river sediments (Changjiang, Huanghe and Yalujiang), shown by obvious enrichments of LREE (light rare earth element) relative to UCC (upper continental crust). Variations of source rock compositions in the drainage basins are responsible for the differences of REE compositions between the river sediments. REE fractionation parameters including (La/Yb)UCC and (Gd/Yb)UCC as well as the ratios of La/Sc and Th/Sc can be treated as proper proxies for identifying the Chinese river sediments from those Korean river matters, and furthermore, for studying the provenances and paleoenvironmental changes of the marginal seas of China.展开更多
Based on analysis of magnetic febric and magnetic relict, the paleocurrents recorded in drilling cores in Subei coastal plain are bidirectional. NE_SW in the northern core and NW_SE in the southern core. The paleocurr...Based on analysis of magnetic febric and magnetic relict, the paleocurrents recorded in drilling cores in Subei coastal plain are bidirectional. NE_SW in the northern core and NW_SE in the southern core. The paleocurrent pattern in the area is similar to that of the tidal current system in the South Yellow Sea. So it is inferred that the convergent_divergent tidal current system existed during stage of sand body formation, and they should be radial in plane.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 49999560 and 49976016) and the State Key Basic Research and Development Program (Grant No. 2000078505).
文摘The relatively abundant palynomorphs were recovered from the samples of the first paleosol layer of core CY in Shanghai for the first time. A total of 55 genera and families of spore, pollen and phytoplankton were identified. According to the characteristics of the palynological assemblages, the depositional conditions in the development period of the paleosols were discussed and the microfossil evidence to study the origin of the paleosols in the Yangtze Delta area was provided as well. The research results show that paleosols should be freshwater deposits. The palynological assemblage sequence in the first paleosol layer reveals fluctuations of freshwater palynomorphs, mainly Concentricystis, and terricolous herbs pollen, reflecting the alternations of deposition and exposure in the development period of the paleosols. Concentricystis developed prosperously in the period of flood, while terricolous herbs grew on the emerged land in the period of exposure. The variations in the palynological
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.4997601 6 and 40206008)the Korean Science and Engineering Foundation.
文摘Rare earth element (REE) compositions of the suspended sediments from the rivers around the Yellow Sea were different in that Korean river sediments (Han, Keum and Yeongsan Rivers) yield stronger fractionations than Chinese river sediments (Changjiang, Huanghe and Yalujiang), shown by obvious enrichments of LREE (light rare earth element) relative to UCC (upper continental crust). Variations of source rock compositions in the drainage basins are responsible for the differences of REE compositions between the river sediments. REE fractionation parameters including (La/Yb)UCC and (Gd/Yb)UCC as well as the ratios of La/Sc and Th/Sc can be treated as proper proxies for identifying the Chinese river sediments from those Korean river matters, and furthermore, for studying the provenances and paleoenvironmental changes of the marginal seas of China.
文摘Based on analysis of magnetic febric and magnetic relict, the paleocurrents recorded in drilling cores in Subei coastal plain are bidirectional. NE_SW in the northern core and NW_SE in the southern core. The paleocurrent pattern in the area is similar to that of the tidal current system in the South Yellow Sea. So it is inferred that the convergent_divergent tidal current system existed during stage of sand body formation, and they should be radial in plane.
