海生爬行动物在早三叠世生物复苏过程中遍布在古特提斯洋和西泛大洋,南漳‒远安动物群是早三叠世最早的海生爬行动物群落之一.然而,该动物群的具体生存时代以及所赋存的嘉陵江组地层的沉积时代都还不够明确.在湖北南漳‒远安一带针对南漳...海生爬行动物在早三叠世生物复苏过程中遍布在古特提斯洋和西泛大洋,南漳‒远安动物群是早三叠世最早的海生爬行动物群落之一.然而,该动物群的具体生存时代以及所赋存的嘉陵江组地层的沉积时代都还不够明确.在湖北南漳‒远安一带针对南漳‒远安动物群赋存地层开展岩石地层和同位素年代学研究.南漳‒远安动物群产于嘉陵江组二段上部的纹层状灰岩中,并获得SHRIMP II U-Pb年龄247.8±1.2 Ma.建立了南漳‒远安地区嘉陵江组上部地层对比格架,证明南漳‒远安动物群生存在早三叠世Spathian晚期.展开更多
The Quaternary sediments in the Yangtze delta are loose and lack precise stratification marks in the lithology. Moreover, due to the limitations of dating methods, it is difficult for Quaternary cores to deliver accur...The Quaternary sediments in the Yangtze delta are loose and lack precise stratification marks in the lithology. Moreover, due to the limitations of dating methods, it is difficult for Quaternary cores to deliver accurate age constraints. Thus, it is a challenge to establish the Quaternary stratigraphic framework. Gravity core LZK1 was drilled on Hengsha Island, Shanghai, in the Yangtze delta, in 2012. The core was terminated at 403.83 m below the local land surface, the uppermost 291.2 m comprising a thick sequence of Quaternary sediments. This study investigated the stratigraphic subdivision and paleoenvironmental change of the Quaternary sediments. From bottom to top, the Quaternary stratigraphic sequence can be subdivided into the lower Pleistocene Anting Formation, Middle Pleistocene Jiading Formation, Upper Pleistocene Chuansha Formation and Nanhui Formation, Holocene Loutang Formation, Shanghai Formation, and Rudong Formation. According to this study, the Hengsha Island area was dominated by a freshwater lacustrine environment during the early Pleistocene, an alternation of shallow lake and shore lake environment during the Middle Pleistocene, a delta plain to lagoonal environment during the early Upper Pleistocene, a fluvial channel to floodplain environment from the LGM(Last Glacial Maximum) to the end of the Upper Pleistocene, and a delta environment during the Holocene.展开更多
文摘海生爬行动物在早三叠世生物复苏过程中遍布在古特提斯洋和西泛大洋,南漳‒远安动物群是早三叠世最早的海生爬行动物群落之一.然而,该动物群的具体生存时代以及所赋存的嘉陵江组地层的沉积时代都还不够明确.在湖北南漳‒远安一带针对南漳‒远安动物群赋存地层开展岩石地层和同位素年代学研究.南漳‒远安动物群产于嘉陵江组二段上部的纹层状灰岩中,并获得SHRIMP II U-Pb年龄247.8±1.2 Ma.建立了南漳‒远安地区嘉陵江组上部地层对比格架,证明南漳‒远安动物群生存在早三叠世Spathian晚期.
基金funded by the Geological Survey of China(Nos.DD20190370,DD20160345-07)the National Natural Science Foundation(No.40902049)。
文摘The Quaternary sediments in the Yangtze delta are loose and lack precise stratification marks in the lithology. Moreover, due to the limitations of dating methods, it is difficult for Quaternary cores to deliver accurate age constraints. Thus, it is a challenge to establish the Quaternary stratigraphic framework. Gravity core LZK1 was drilled on Hengsha Island, Shanghai, in the Yangtze delta, in 2012. The core was terminated at 403.83 m below the local land surface, the uppermost 291.2 m comprising a thick sequence of Quaternary sediments. This study investigated the stratigraphic subdivision and paleoenvironmental change of the Quaternary sediments. From bottom to top, the Quaternary stratigraphic sequence can be subdivided into the lower Pleistocene Anting Formation, Middle Pleistocene Jiading Formation, Upper Pleistocene Chuansha Formation and Nanhui Formation, Holocene Loutang Formation, Shanghai Formation, and Rudong Formation. According to this study, the Hengsha Island area was dominated by a freshwater lacustrine environment during the early Pleistocene, an alternation of shallow lake and shore lake environment during the Middle Pleistocene, a delta plain to lagoonal environment during the early Upper Pleistocene, a fluvial channel to floodplain environment from the LGM(Last Glacial Maximum) to the end of the Upper Pleistocene, and a delta environment during the Holocene.
