Sedimentary sequences in the Subei Basin are complex and have been affected by interactions between the ocean and rivers since the Late Pliocene, including the Yellow River, Huaihe River, and the Yangtze River. This s...Sedimentary sequences in the Subei Basin are complex and have been affected by interactions between the ocean and rivers since the Late Pliocene, including the Yellow River, Huaihe River, and the Yangtze River. This sedimentary evolution, in particular the timing of Pleistocene transgressions, has long been a matter of controversy owing to the lack of precise chronological evidence. The aim of this study is to explore the evolution of the sedimentary environment throughout the past 3.00 Ma in this region on the basis of a comprehensive analysis of particle size and foraminifera and ostracods collected in the TZK9 core from the Subei Basin combined with geochronological studies of magnetostratigraphy, AMS^(14)C and optically stimulated luminescence(OSL). The results show that fluvial facies in the sedimentary environment from 3.00 to 1.01 Ma. There were fluvial facies and reflects six sea-level high stands from 1.01 to 0.25 Ma. The study area was affected by four large-scale transgressions since 0.25 Ma. The four marine sedimentary layers known as DU7(buried at 48–52 m), DU5(buried at 35–41 m), DU3(buried at 16–23 m), and DU1(buried at 2–4 m) are recorded in the MIS7(210–250 ka), MIS5, MIS3, and Holocene, respectively. The magnitude of the DU5 transgression was identical to that of the DU3 transgression, both were larger than the DU7 transgression, and the DU1 transgression was the weakest. The variation of transgression strength reflects the influence of global changes in sea level, tectonic subsidence, shell ridges, and sand dams. In the TZK9 core, we found evidence of seven sea-level high stands from the Early–Middle Pleistocene, and the first one caused by regional rapid subsidence and could be traced back to 0.83-0.84 Ma. The sea-level high stands and the age of the first one recorded above was different from other cores in eastern China, this was caused by the lack of absolute age control and the differences in paleotopography during this period. This study reconstructs sedimentary evolution, determines the transgression and its age, establishes the chronology since the Late Pliocene, and provides a scientific framework for further paleoenvironmental and tectonic studies. The results of this study highlight the important role that local tectonics and global sea level play in the sedimentary evolution and transgressions that have occurred in the western Subei Basin.展开更多
Whether there has been water on the Moon or not is a heated debate.A very detailed examination of satellite photographs of the Tycho Meteorite Crater shows what appears to be a lake(A-Lake).
The nature of the Moon＇s surface has always been controversial. American scientists first suggested that there has been water and ice on the Moon （Watson et al., 1961）, a hypothesis supported by some but not other ...The nature of the Moon＇s surface has always been controversial. American scientists first suggested that there has been water and ice on the Moon （Watson et al., 1961）, a hypothesis supported by some but not other researchers （Compiling Committee, 2006; Ouyang, 2005; Wang, 2010）. So whether there has been or is any water on the Moon or not, is a matter of heated debate.展开更多
Based on the data from 121 boreholes(9552 samples) and the distribution pattern analysis of foraminifera,ostracods,pollen,spores,wooly rhinoceros,elephants,water buffalo and beachrocks in time and space,three abrupt c...Based on the data from 121 boreholes(9552 samples) and the distribution pattern analysis of foraminifera,ostracods,pollen,spores,wooly rhinoceros,elephants,water buffalo and beachrocks in time and space,three abrupt climate change events since the Late Pleistocene are recognized in the North China Plain.These climatic events caused three very warm periods and two severely cold periods.During the two warmest periods,the mean temperature was about 7℃ higher than at present,and during the two extreme cold periods,the mean temperature was some 6℃ lower than today.Moreover,the last warm period was in the Middle Holocene;its mean temperature was 3℃ higher than now in the region.展开更多
基金supported by the China Geological Survey Project(DD20160060,121201140 42901)the National Natural Science Foundation of China(41502119,41371207)
文摘Sedimentary sequences in the Subei Basin are complex and have been affected by interactions between the ocean and rivers since the Late Pliocene, including the Yellow River, Huaihe River, and the Yangtze River. This sedimentary evolution, in particular the timing of Pleistocene transgressions, has long been a matter of controversy owing to the lack of precise chronological evidence. The aim of this study is to explore the evolution of the sedimentary environment throughout the past 3.00 Ma in this region on the basis of a comprehensive analysis of particle size and foraminifera and ostracods collected in the TZK9 core from the Subei Basin combined with geochronological studies of magnetostratigraphy, AMS^(14)C and optically stimulated luminescence(OSL). The results show that fluvial facies in the sedimentary environment from 3.00 to 1.01 Ma. There were fluvial facies and reflects six sea-level high stands from 1.01 to 0.25 Ma. The study area was affected by four large-scale transgressions since 0.25 Ma. The four marine sedimentary layers known as DU7(buried at 48–52 m), DU5(buried at 35–41 m), DU3(buried at 16–23 m), and DU1(buried at 2–4 m) are recorded in the MIS7(210–250 ka), MIS5, MIS3, and Holocene, respectively. The magnitude of the DU5 transgression was identical to that of the DU3 transgression, both were larger than the DU7 transgression, and the DU1 transgression was the weakest. The variation of transgression strength reflects the influence of global changes in sea level, tectonic subsidence, shell ridges, and sand dams. In the TZK9 core, we found evidence of seven sea-level high stands from the Early–Middle Pleistocene, and the first one caused by regional rapid subsidence and could be traced back to 0.83-0.84 Ma. The sea-level high stands and the age of the first one recorded above was different from other cores in eastern China, this was caused by the lack of absolute age control and the differences in paleotopography during this period. This study reconstructs sedimentary evolution, determines the transgression and its age, establishes the chronology since the Late Pliocene, and provides a scientific framework for further paleoenvironmental and tectonic studies. The results of this study highlight the important role that local tectonics and global sea level play in the sedimentary evolution and transgressions that have occurred in the western Subei Basin.
基金financially supported by the National Key Research and Development Project(grant No.2016YFC060110602)the China-Germany Cooperation Fund(grant No.41761134096)“The Application and Research of the Scientific Data of Lunar Exploration Project”(grant No.2010AA12220105)from the National High Technology Research and Development Program of China(“863”Program)
文摘Whether there has been water on the Moon or not is a heated debate.A very detailed examination of satellite photographs of the Tycho Meteorite Crater shows what appears to be a lake(A-Lake).
基金funds from The National High Technology Research and Development Program of China("863"Program):"The application and research of the scientific data of the lunar exploration project"(Project NO.2010AA12220105)
文摘The nature of the Moon＇s surface has always been controversial. American scientists first suggested that there has been water and ice on the Moon （Watson et al., 1961）, a hypothesis supported by some but not other researchers （Compiling Committee, 2006; Ouyang, 2005; Wang, 2010）. So whether there has been or is any water on the Moon or not, is a matter of heated debate.
文摘Based on the data from 121 boreholes(9552 samples) and the distribution pattern analysis of foraminifera,ostracods,pollen,spores,wooly rhinoceros,elephants,water buffalo and beachrocks in time and space,three abrupt climate change events since the Late Pleistocene are recognized in the North China Plain.These climatic events caused three very warm periods and two severely cold periods.During the two warmest periods,the mean temperature was about 7℃ higher than at present,and during the two extreme cold periods,the mean temperature was some 6℃ lower than today.Moreover,the last warm period was in the Middle Holocene;its mean temperature was 3℃ higher than now in the region.
