A marine stratigraphic sequence across the Pliocene / Pleistocene boundary has been found in the north-ern continental shelf of the South China Sea. The marine Quaternary deposits in the Yinggehai Basin may ex-ceed 2,...A marine stratigraphic sequence across the Pliocene / Pleistocene boundary has been found in the north-ern continental shelf of the South China Sea. The marine Quaternary deposits in the Yinggehai Basin may ex-ceed 2,000 m in thickness, probably providing the best section for studying the lower boundary of the marinePleistocene in South China. The vertical succession with planktonic foraminifers and nannofossils revealed inboreholes in the basin has been well correlated with that in the international stratotype section of thePliocene / Pleistocene boundary at Vrica, Italy, resulting in the acquirement of a biostratigraphic boundary at1.64 Ma. This boundary, however, does not coincide with any prominent lithological palaeoenvironmentalchanges in the study area and can hardly be used in geological practice. There are, in contrast, significantchanges at the level of LAD of Globorotalia multicamerata sensu lato located below the above-mentionedboundary. The percentage of planktonic foraminifers in the total population and preservation of foraminiferaltests display great changes at this level corresponding to a clear onlap on the seismic profiles and indicating adepositional hiatus at ca. 2.0-2.5 Ma. Since the level can be widely traced in the Pearl River Mouth Basin andthe Beibu Gulf Basin and well corresponds with the marked depositional environmental changes recorded inthe west Pacific and other regions, it is recommended that the Plio / Pleistocene boundary be drawn at the levelof Gr. multicamerata sensu lato LAD, roughly concurrent with the Gauss / Matuyama turn.展开更多
The present study examines material quarrying, utilization, and exploitation strategy with respect to availability, quality and distribution at Donggutuo, a Lower Pleistocene archeological site in the Nihewan Basin of...The present study examines material quarrying, utilization, and exploitation strategy with respect to availability, quality and distribution at Donggutuo, a Lower Pleistocene archeological site in the Nihewan Basin of North China. Through identification of the bedrocks in the vicinity, the analysis reveals that raw materials available at the Donggutuo site are mainly chert, dolomicrite, siliceous dolomite, siliceous limestone, tectonic breccia, quartzite and intermediate lava. Related documents and a geological survey of the area demonstrate that the chert was quarried from dolomite within the Gaoyuzhuang Formation of the Mesoproterozoic Changcheng Group, and the quartzite from the Yousuopu Formation of the Archeozoic Qianxi Group, as well as from Jurassic volcanic lava. Fractures formed by tectonic movements of the Yanshan Stage and the Himalaya Stage made it convenient to quarry these materials. It is observed that fragmentary rock pieces were directly collected and quarried from local fracture belts and that this became the principal strategy of raw material exploitation adopted by the Donggutuo toolmakers. In general, raw materials were not efficiently used, and many of them could have been reduced, retouched and used again. Some suggestions are also proposed to improve the understanding of earlyhumans’ tool complex in the Nihewan Basin.展开更多
文摘A marine stratigraphic sequence across the Pliocene / Pleistocene boundary has been found in the north-ern continental shelf of the South China Sea. The marine Quaternary deposits in the Yinggehai Basin may ex-ceed 2,000 m in thickness, probably providing the best section for studying the lower boundary of the marinePleistocene in South China. The vertical succession with planktonic foraminifers and nannofossils revealed inboreholes in the basin has been well correlated with that in the international stratotype section of thePliocene / Pleistocene boundary at Vrica, Italy, resulting in the acquirement of a biostratigraphic boundary at1.64 Ma. This boundary, however, does not coincide with any prominent lithological palaeoenvironmentalchanges in the study area and can hardly be used in geological practice. There are, in contrast, significantchanges at the level of LAD of Globorotalia multicamerata sensu lato located below the above-mentionedboundary. The percentage of planktonic foraminifers in the total population and preservation of foraminiferaltests display great changes at this level corresponding to a clear onlap on the seismic profiles and indicating adepositional hiatus at ca. 2.0-2.5 Ma. Since the level can be widely traced in the Pearl River Mouth Basin andthe Beibu Gulf Basin and well corresponds with the marked depositional environmental changes recorded inthe west Pacific and other regions, it is recommended that the Plio / Pleistocene boundary be drawn at the levelof Gr. multicamerata sensu lato LAD, roughly concurrent with the Gauss / Matuyama turn.
文摘The present study examines material quarrying, utilization, and exploitation strategy with respect to availability, quality and distribution at Donggutuo, a Lower Pleistocene archeological site in the Nihewan Basin of North China. Through identification of the bedrocks in the vicinity, the analysis reveals that raw materials available at the Donggutuo site are mainly chert, dolomicrite, siliceous dolomite, siliceous limestone, tectonic breccia, quartzite and intermediate lava. Related documents and a geological survey of the area demonstrate that the chert was quarried from dolomite within the Gaoyuzhuang Formation of the Mesoproterozoic Changcheng Group, and the quartzite from the Yousuopu Formation of the Archeozoic Qianxi Group, as well as from Jurassic volcanic lava. Fractures formed by tectonic movements of the Yanshan Stage and the Himalaya Stage made it convenient to quarry these materials. It is observed that fragmentary rock pieces were directly collected and quarried from local fracture belts and that this became the principal strategy of raw material exploitation adopted by the Donggutuo toolmakers. In general, raw materials were not efficiently used, and many of them could have been reduced, retouched and used again. Some suggestions are also proposed to improve the understanding of earlyhumans’ tool complex in the Nihewan Basin.
