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The species diversity of fusulinaceans and high-frequency sea-level changes in the Carboniferous-Permian boundary section at Xikou, Zhen'an County,Shaanxi Province, China 被引量:2
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作者 ZHANG Haijun1, WANG Xunlian2, DING Lin1, XIA Guoying3 & WANG Lei2 1. Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2. Faculty of Earth Sciences and Mineral Resources, China University of Geosciences, Beijing 100083, China 3. Tianjin Institute of Geology and Mineral Resources, Tianjin 300170, China 《Science China Earth Sciences》 SCIE EI CAS 2006年第7期673-683,共11页
The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws ... The study on the interrelation between sea-level changes and biodiversity with its evolu-tion has great significance for understanding the impact of global changes on organic evolution and exploring the inherent laws of life-environment coevolution in geological history. In this paper, the stratigraphic distribution of fusulinacean fauna in the Carboniferous-Permian boundary section at Xikou, Zhen’an County, Shaanxi Province, is analyzed quantitatively, and the relationship between the species diversity of fusulinaceans and relative sea-level changes is discussed. As a whole, the spe-cies numbers of fusulinacean fauna experience a rapid increase and an obvious decline in Xikou, Zhen’an County, from the Late Carboniferous to the Early Permian. There is a significant increase in species diversity around the Carboniferous-Permian boundary, which is one of the biggest bio-events of the fusulinacean fauna, and represents the radiation of Pseudoschwagerininae subfamily in the studied area. Integrated fusulinacean species diversity into sequence stratigraphic framework, de-tailed study suggests that the species diversity of the fusulinaceans is closely related to its relative stratigraphic location, and is essentially controlled by the sea-level changes, especially by the high-frequency sea-level changes. Generally, the species diversity of fusulinaceans is low, and the number of first and last appearance datum is small in the lower unit of high-frequency depositional cycle formed during the quick rise of the sea level; whereas the species diversity of fusulinaceans is high, and the number of first and last appearance datum is large in the upper unit of high-frequency cycle formed during the slow fall of the sea level. Within the third-order depositional sequence, the species diversity of the fusulinaceans at the first flooding surfaces and the maximum flooding surfaces is low, and it increases upward. The fusulinacean species diversity is low within the transgressive systems track, and it is high within the highstand systems track. The second-order rise and fall in sea level coincide with the bloom and decline of high order taxa of fusulinaceans. 展开更多
关键词 fusulinaceans species diversity high-frequency cyclothem sequence stratigraphy sea-level changes CARBONIFEROUS-PERMIAN boundary Zhen'an Shaanxi.
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Carbonate Diagenesis Controlled by Glacioeustatic Sea-Level Changes: A Case Study from the Carboniferous-Permian Boundary Section at Xikou, China 被引量:3
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作者 张海军 丁林 +3 位作者 王训练 王雷 王清山 夏国英 《Journal of China University of Geosciences》 SCIE CSCD 2006年第2期103-114,共12页
The platform-facies carbonate rocks of the Carboniferous-Permian boundary strata are well developed and outcropped in Xikou (西口), Zhen'an (镇安) County, Shaanxi ( 陕西 ) Province, China. The carbonate diagenc... The platform-facies carbonate rocks of the Carboniferous-Permian boundary strata are well developed and outcropped in Xikou (西口), Zhen'an (镇安) County, Shaanxi ( 陕西 ) Province, China. The carbonate diagencsis in the Carboniferous-Permian boundary section at Xikou contains many processes with conspicuous effects, including micritization, cementation, mechanical and chemical compaction, neomorphism, and dissolution. Based on mineralogical composition and microfabrics, the diagenetic environments are distinguished into marine, near surface meteoric and burial environments. Detailed petrographical observation of abundant thin sections integrated with previous studies on sequence stratigraphy reveals that the carbonate diagenesis in the Carboniferous-Permian boundary section is related to the relative stratigraphic position of the rocks in the high-frequency cycles and controlled by the glacioeustatic sea-level changes. There are distinctive differences in diagenetic patterns between the lower transgressive sequence and the upper regressive sequence in a cyclothem. The diagenesis in the lower transgressive sequence is mainly characterized by pressure dissolution and recrystallization of mudstone and wackstone in a burial environment, and the diagenesis in the upper regressive sequence by cementation and leaching of freshwater in a meteoric environment. 展开更多
关键词 CARBONATE DIAGENESIS diagenetic environment high-frequency cycle glacioeustatic sealevel change Carboniferous-Permian boundary Zhen'an Shaanxi
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Climate-environmental Deteriorations in a Greenhouse Earth System:Causes and Consequences of Short-Term Cretaceous Sea-Level Changes(a Report on IGCP 609)
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作者 Michael WAGREICH Benjamin SAMES HU Xiumian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第S01期144-146,共3页
Anthropogenic global warming and resulting sea-level rise in response to enhanced atmospheric greenhouse gases and melting of the Earth’s continental ice shields have become issues of continuously growing interest fo... Anthropogenic global warming and resulting sea-level rise in response to enhanced atmospheric greenhouse gases and melting of the Earth’s continental ice shields have become issues of continuously growing interest for the scientific community as well as the public,pointing to threads of societies in a future greenhouse Earth System. 展开更多
关键词 sea-level change GREENHOUSE CRETACEOUS
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Transgressions and the sea-level changes of the western Taiwan Strait since the Late Pleistocene
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作者 Lan Dongzhao, Zhang Weilin, Chen Chenghui, Xie Zaituan, Yu Yongfen and Cai Feng Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1993年第4期617-627,共11页
The sedimentary sequences since the Late Pleistocene can be divided into Layers E, D, C, B, A from old to young according to systematic analysis of grain-size, pollen and spore, diatom, foraminifera, radiocarbon datin... The sedimentary sequences since the Late Pleistocene can be divided into Layers E, D, C, B, A from old to young according to systematic analysis of grain-size, pollen and spore, diatom, foraminifera, radiocarbon dating and paleogeomagnetism of 16 sedimentary cores from the sea area of the western Taiwan Strait. The results proved the existences of the Langqi transgression (upper section of Layer D) formed in middle and late stages of early Wurm glacial period, Fuzhou transgression (Layer C) formed in Wurm sub-interglacial period and Changle transgression (Layer A) formed in postglacial period. It was also the first time to discover the Jinmen transgression (Layer E) formed in Riss -Wurm interglacial period. In this paper it is proposed that most part of the Taiwan Strait emerged as land in the early stage of early Wurm glacial period, and was still under sublittoral environment in late Wurm glacial period, as well as the existence of Dongshan Continental Bridge was in 8×103 a BP. 展开更多
关键词 Taiwan Strait sedimentary sequence TRANSGRESSION sea-level change
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Sedimentary Features and Sea-Level Changes Reflected in Drill Holes in the Zhuhai Area
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作者 CHEN Junren WAN Ling 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1999年第2期216-224,共9页
Abstract Experimental examinations and analyses have been made of the sediments from drill holes in the Zhuhai area, Guangdong Province. The studies show that there occurred four transgressions in this area over the h... Abstract Experimental examinations and analyses have been made of the sediments from drill holes in the Zhuhai area, Guangdong Province. The studies show that there occurred four transgressions in this area over the historical times. The first transgression occurred at 7500 a B.P., with the maxium sea level up to about 1 m above the present level. The second transgression occurred at 5750 a B.P., with the sea level possibly 4 m higher than the present. The third and fourth transgressions took place at 4650 a B.P. and 2600 a B.P. respectively, which lasted for a long time with multiple fluctuations. The fifth transgression is in process. It could be predicted that the sea level at Zhuhai would rise by 15–20 cm in the coming 50 years. 展开更多
关键词 sedimentary features sea-level changes Zhuhai
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Preliminary research on sea-level changes of the South China coast since late Epipleistocene
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作者 Zhang Hunan Zhao Hongmei Seismological Bureau of Guangdong Province, Guangzhou 510070, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1991年第4期565-591,共27页
Several views on sea-level changes of the South China coast are briefly introduced in this paper. On the basis of 236 samples whose ages are determined by 14C chronological method and their sites are corrected with an... Several views on sea-level changes of the South China coast are briefly introduced in this paper. On the basis of 236 samples whose ages are determined by 14C chronological method and their sites are corrected with ancient water depth and crustal deformation, a basic model about sea-level changes of the South China coast since late Epipleistocene is set up. This model basically accords with the general cognitions of predecessors, i. e. it not only represents the common characteristics of sea-level changes of the East China coast but has some features of the South China coast itself. In general, this model is relatively close to the Fairbridge's curve, indicating that the sea-level undulations exist since 6 ka ago but the ranges of undulations are slightly larger than those of Fairbridge's curve. 展开更多
关键词 than Preliminary research on sea-level changes of the South China coast since late Epipleistocene HO
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Devonian Sea-Level Change Rhythms in South China and Coupling Relationships Among the Earth-spheres 被引量:10
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作者 Gong Yiming,Faculty of Earth Science, China University of Geosciences, Wuhan,Hubei, 430074Wu Yi,Guangxi Institute of Geology, Nanning, GuangxiDu Yuansheng, Feng Qinglai and Liu BenpeiChina University of Geosciences, Wuhan, Hubei, 430074 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1997年第4期370-385,共16页
Twenty orthosequences and their corresponding sea-level change (SLC) cycles have been recognized in the Devonian overlying the Caledonian unconformity, of which 9, 5.5 and 5.5 occurred in the Lower, Middle and Upper D... Twenty orthosequences and their corresponding sea-level change (SLC) cycles have been recognized in the Devonian overlying the Caledonian unconformity, of which 9, 5.5 and 5.5 occurred in the Lower, Middle and Upper Devonian respectively. They can be grouped into 4 orthosequence sets, in which the maximum flooding surfaces lie in the sulcutus Zone (D12), perbonus Zone (D13), Middle and Upper varcus Zone (D22) and gigas Zone (D21) respectively. Four instant palaeogeographical reconstructions of South China have been made in the Emsian and Givetian. Devonian sea-level change rhythms of South China can be divided into 3 categories: the autorhythmic, the worldwide and regional allorhythmic, and the coupling-rhythmic. They developed respectively in the Famennian, Pragian, Eifelian, Lochkovian, Emsian, Givetian, Frasnian and the F / F (between the Frasnian and Famennian) event. The cause of the worldwide allorhythmic SLC of the Pragian and Eifelian under comparatively dry, warm and tranquil conditions may be related to the pulsating expanding and contracting of the oceanic basin volume or the earth volume pulsation, rather than the common glaciation and plate tectonism. The coupling-rhythmic SLC related to the F/ F event is a sensitive indicator of the interaction between terrestrial and extraterrestrial factors, and coordinated action among the earth-spheres. 展开更多
关键词 sequence stratigraphy sea-level change rhythm coupling among the earth-spheres instant palaeogeographical reconstruction DEVONIAN South China
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Changes in the global cryosphere and their impacts:A review and new perspective 被引量:2
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作者 ShiYin Liu TongHua Wu +6 位作者 Xin Wang XiaoDong Wu XiaoJun Yao Qiao Liu Yong Zhang JunFeng Wei XiaoFan Zhu 《Research in Cold and Arid Regions》 CSCD 2020年第6期343-354,共12页
As one of the five components of Earth's climatic system,the cryosphere has been undergoing rapid shrinking due to global warming.Studies on the formation,evolution,distribution and dynamics of cryospheric compone... As one of the five components of Earth's climatic system,the cryosphere has been undergoing rapid shrinking due to global warming.Studies on the formation,evolution,distribution and dynamics of cryospheric components and their interactions with the human system are of increasing importance to society.In recent decades,the mass loss of glaciers,including the Greenland and Antarctic ice sheets,has accelerated.The extent of sea ice and snow cover has been shrinking,and permafrost has been degrading.The main sustainable development goals in cryospheric regions have been impacted.The shrinking of the cryosphere results in sea-level rise,which is currently affecting,or is soon expected to affect,17 coastal megacities and some small island countries.In East Asia,South Asia and North America,climate anomalies are closely related to the extent of Arctic sea ice and snow cover in the Northern Hemisphere.Increasing freshwater melting from the ice sheets and sea ice may be one reason for the slowdown in Atlantic meridional overturning circulation in the Arctic and Southern Oceans.The foundations of ports and infrastructure in the circum-Arctic permafrost regions suffer from the consequences of permafrost degradation.In high plateaus and mountainous regions,the cryosphere's shrinking has led to fluctuations in river runoff,caused water shortages and increased flooding risks in certain areas.These changes in cryospheric components have shown significant heterogeneity at different temporal and spatial scales.Our results suggest that the quantitative evaluation of future changes in the cryosphere still needs to be improved by enhancing existing observations and model simulations.Theoretical and methodological innovations are required to strengthen social economies'resilience to the impact of cryospheric change. 展开更多
关键词 cryospheric change sea-level rise water resources climate change
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Coastal dune rock development and Holocene climate changes in South China 被引量:1
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作者 WANG Wei WU Zheng 《Journal of Geographical Sciences》 SCIE CSCD 2010年第3期469-480,共12页
Coastal dune rocks in China are eolian sands cemented by calcium carbonate under subaerial conditions, widely distributing on the tropical and subtropical coasts of South China. Particular temperature and precipitatio... Coastal dune rocks in China are eolian sands cemented by calcium carbonate under subaerial conditions, widely distributing on the tropical and subtropical coasts of South China. Particular temperature and precipitation as well as local wave and landform conditions are required for the formation of the dune rocks. A correspondence was found between Holocene environmental changes and coastal dune rock development by comparing the features of the sea-level and climate changes in the Holocene period with the ages, scales, and cementation of the dune rocks on the South China coasts. The findings provide well grounded explanation for some problems unresolved in the past researches on the coastal dune rock in South China: (1) There were no dune rocks with ages older than 6000 years in South China because the dune rocks formed before 6000 a BP were covered by the sea water that rose in the later period; (2) the dune rocks with ages of around 3000 a BP were widely found in South China today because the coastal dunes were cumulated on a large scale at that time as a result of temperature falling after the end of Megathermal; (3) Medieval Warm Period was the main period for the eolian dunes to be cemented into the coastal dune rocks in South China; (4) lack of dune rocks of younger than 1000 a BP was accounted for by that the climate conditions in recent one thousand years were not suitable for the cementation. 展开更多
关键词 coastal dune rock South China coast Holocene climate change Holocene sea-level change
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An Outline of Mesozoic to Paleogene SequenceStratigraphy and Sea-Level Changes in Northern Himalayas,Southern Xizang 被引量:1
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作者 Shi Xiaoying Yin Jiarun(Department of Geology and Mineral Resources, China University of Geosciences,Beijing 100083) 《Journal of Earth Science》 SCIE CAS CSCD 1995年第1期16-40,共20页
In the Northern Himalayan region of Southern Xizang (Tibet),from the Lower Triassic to Upper Eocene 73 Sequences have been identified, with an average duration of 2.9 Ma;these can in turn be grouped into 24 super-Sequ... In the Northern Himalayan region of Southern Xizang (Tibet),from the Lower Triassic to Upper Eocene 73 Sequences have been identified, with an average duration of 2.9 Ma;these can in turn be grouped into 24 super-Sequences and 6 super-sequence sets. During Mesozoic and Paleogene, several large sea - level falls occurred in the Eastern Neo-Tethys. Among the recognized sea- level falls, the important ones include those at the ages of 255 Ma, 215 Ma,177 Ma, 138 Ma, 103 Ma and 68 Ma .Those at 239 Ma, 215 Ma, 157 Ma,80 Ma, 50Ma and 36 Ma are also significant. The third-order Sequences and sea-level cycles Probably reflect mainly global sea - level fluctuations, while the higher rank cycles seem more closely related to the basin evolution of the Neo-Tethys. Based on the study, six major periods have been suggested for ths tectonic evolution of the Eastern Neo-Tethys and the plates, i. e. the Pangea Period (Pre-Triassic), continental rifting Period (Triassic to Early Jurassic ), inter-continental sea Period (Middle Jurassic ), continental divergence period (late Middle Jurassic to Early Cretaceous ), continental convergence period (Late Cretaceous ) and the continental collision Period (Paleogene ). These major Periods can be further subdivided into eight stages according to the basin evolution. In each of the periods and Stages, Sequences and their boundaries show clear characters related to the tectonic background. The study indicater that the initial breakup of the Pangea along the Indus- Yarlung may have taken Place around 239 Ma. The Late Bathonian to Early Callovian seems to have been a critical time in the evolution of the Neo-Tethys, with the turning Point around 158 Ma. The blocks split from the northern margin of the Gondwana continual did not obviously drift away from the Indian Plate until Callovian .The oceanic crust subduction in the Neo- Tethys may have Started at 113Ma, while the contraction of the ocean probably began at 107- 103 Ma. The initial contact of the Indian Plate with the Eurasian plate may have taken Place around 80 Ma, with strong uplifting and thrushng in Late Paleocene. 展开更多
关键词 Sequence stratigraphy sea-level change MESOZOIC Cenozoic Northern Himalayas southern Xizang.
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Sea level change and forecast in the future — climate of the past,today and the future 被引量:1
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作者 岳军 DONG yue +3 位作者 陈满春 韩芳 段焕春 王国明 《Marine Science Bulletin》 CAS 2011年第2期33-50,共18页
The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change... The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change is really a sensitive integral variation value of many variations, or a combined function of coupling effects of various big systems. Therefore the above mentioned superposed action of different systems and the coupling effect of sun earth and biological aspects may be called as sun earth biological coupling effect system. Based on this hypothesis, the corresponding sun dynamic, air dynamic, water dynamic and earth dynamic conceptional models are established in order to research the multiple coupling effects and feedback machsnism between these big systems. In order to determine the relations, effectness and coherent relation of different variations, the quantity, analysis is conducted through collective variation and stage division. The quantity analysis indicates that the earths spindle rotation speed is the dynamic mechanism controlling the sea level change of fluctuation. The change rate of sea level in the world is +1.32 + 0.22 mm/a, while the sea level change rate in China is only+1.39 + 0.26 mm/a in average. If take the CO2 content as the climate marker, eight cold stages (periods) are grouped out since two hundreds years AC. The extreme cold of the eighth cold stage started approximately at 1850 years AC. and if the stage from the extreme cold to extreme warm is determined as long as 200 years, the present ongoing warm stage will end at about 2050 years, there after the temperature will begin to tower. If the stage between cold and warm extremes lasts for 250 years, then the temperature will become lower at about 2100 year. Until to that time, the sea-level is estimated to raise +7 - +11 + 3.5 cm again, and there after, the sea level will begin the new lowering trend. In the same time, the climate will enter into next new cold stage subsequently. 展开更多
关键词 Sun earth biological coupling effect system sea-level change mechanism change rate of the sea-level climate cold stage forecast of the sea-level changes in the future
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Carbon Isotope from Shallow Marine System in North China:Implications for Stratigraphical Correlation and Sea-Level Changes in Cambrian 被引量:2
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作者 Jingxun Zuo Xuejian Zhu +1 位作者 Yonglin Chen Wenjian Zhai 《Journal of Earth Science》 SCIE CAS CSCD 2023年第6期1777-1792,共16页
Cambrian System at the Shatan Section in northern Henan,North China,consists of sedimentary successions of tidal flat and shallow-water carbonate platform facies.Data of carbon isotope(δ^(13)C_(carb))from this sectio... Cambrian System at the Shatan Section in northern Henan,North China,consists of sedimentary successions of tidal flat and shallow-water carbonate platform facies.Data of carbon isotope(δ^(13)C_(carb))from this section reveals five positive δ^(13)C_(carb)(P_(st-1)-P_(st-5))and five negative δ^(13)C_(carb) excursions(N_(st-1)-N_(st-5)).In the positive excursions,δ^(13)C_(carb) rises to 0.88‰,1.05‰,2.04‰,1.00‰ and 2.97‰,respectively,while in the negative excursions δ^(13)C_(carb) drops to -8.00‰,-3.50‰,-1.00‰,-0.33‰ and around -2.00‰,respectively.On the basis of chronostratigraphy of Cambrian,the most remarkable carbon isotope excursions can be correlated regionally and globally.In addition,one second-order and ten third-order sequences have been recognized at this section.Correlating third-order sequences and chemostratigraphy indicates that carbonates from the basal part of the transgression system tract(TST)and the upper part of the high-water system(LHST)generally have lighter δ^(13)C_(carb) values,whereas massive carbonates with microbialite from the lower part of the high-water system tract(EHST)usually have heavier δ^(13)C_(carb) values.The association of δ^(13)C_(carb) values with sea-level fluctuations suggests that the positive carbon isotope excursions or high δ^(13)C_(carb) values may have been caused by an increase in the marine primary productivity in response to maximum seawater flooding during the transgression. 展开更多
关键词 carbon isotope sedimentary rocks sea-level change shallow-water Cambrian System STRATIGRAPHY North China
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Global Sea Level Change and Thermal Contribution 被引量:9
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作者 ZUO Juncheng ZHANG Jianli +2 位作者 DU Ling LI Peiliang LI Lei 《Journal of Ocean University of China》 SCIE CAS 2009年第1期1-8,共8页
The global long-term sea level trend is obtained from the analysis of tide gauge data and TOPEX/Poseidon data. The linear trend of global mean sea level is highly non-uniform spatially, with an average rate of 2.2 mmy... The global long-term sea level trend is obtained from the analysis of tide gauge data and TOPEX/Poseidon data. The linear trend of global mean sea level is highly non-uniform spatially, with an average rate of 2.2 mmyear^-1 in T/P sea-level rise from October 1992 to September 2002. Sea level change due to temperature variation (the thermosteric sea level) is discussed. The results are compared with TOPEX/Poseidon altimeter data in the same temporal span at different spatial scales. It is indicated that the thermal effect accounts for 86% and 73% of the observed seasonal variability in the northern and southern hemispheres, respectively. The TOPEX/Poseidon observed sea level lags behind the TSL by 2 months in the zonal band of 40%-60% in both the northern and southern hemispheres. Systematic differences of about 1-2 cm between TOPEX/Poseidon observations and thermosteric sea level data are obtained. The potential causes tbr these differences include water exchange among the atmosphere, land, and oceans, and some possible deviations in thermosteric contribution estimates and geophysical corrections to the TOPEX/Poseidon data. 展开更多
关键词 global sea level seasonal variation secular change thermosteric sea-level
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Paleoecology of Early Ordovician Reefs in the Yichang Area,Hubei:a Correlation of Organic Reefs Between Early Ordovician and Jurassic 被引量:7
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作者 Chuantao XIAO Meng LI +2 位作者 Wei YANG Mingyi HU Chao LI 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2011年第5期1003-1015,共13页
The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the ... The Early Ordovician System is composed mainly of a series of carbonate platform deposits interbedded with shale and is especially characterized by a large number of organic reefs or buildups that occur widely in the research area.The reefs have different thicknesses ranging from 0.5 m to 11.5 m and lengths varying from 1 m to 130 m.The reef-building organisms include Archaeoscyphia, Recepthaculitids,Batostoma,Cyanobacteria and Pulchrilamina.Through the research of characteristics of the reef-bearing strata of the Early Ordovician in the Yichang area,four sorts of biofacies are recognized,which are(1) shelly biofacies:containing Tritoechia-Pelmatozans community and Tritoechia-Pomatotrema community;(2) reef biofacies:including the Batostoma,Calathium-Archaeoscyphia, Pelmatozoa-Batostoma,Archeoscyphia and Calathium-Cyanobacteria communities; (3) standing-water biofacies:including the Acanthograptus-Dendrogptus and Yichangopora communities;and(4) allochthonous biofacies:containing Nanorthis-Psilocephlina taphocoense community.The analysis of sea-level changes indicates that there are four cycles of sea-level changes during the period when reef-bearing strata were formed in this area,and the development of reefs is obviously controlled by the velocity of sea-level changes and the growth of accommodation space.The authors hold that reefs were mostly formed in the high sea level periods.Because of the development of several subordinate cycles during the sea-level rising,the reefs are characterized by great quantity, wide distribution,thin thickness and small scale,which are similar to that of Juassic reefs in northern Tibet.The research on the evolution of communities shows that succession and replacement are the main forms.The former is favorable to the development of reefs and the latter indicates the disappearance of reefs. 展开更多
关键词 organic reef PALEOECOLOGY sea-level change Early Ordovician Yichang area
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Sea-Level Rise and Coastal Inundation: A Case Study of the Gulf Coast Energy Infrastructure
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作者 David E. Dismukes Siddhartha Narra 《Natural Resources》 2018年第4期150-174,共25页
The United States (U.S.) Gulf Coast is a prominent global energy hub with a set of highly integrated critical energy infrastructure that rivals, if not surpasses, any comparable set of infrastructure anywhere in the w... The United States (U.S.) Gulf Coast is a prominent global energy hub with a set of highly integrated critical energy infrastructure that rivals, if not surpasses, any comparable set of infrastructure anywhere in the world. Past extreme weather events in the region have led to critical energy infrastructure disruptions with national and global implications. Future sea-level rise (SLR), coupled with other natural hazards, will lead to a significant increase in energy infrastructure damage exposure. This research assesses coastal energy infrastructure that is at risk from various fixed SLR outcomes and scenarios. The results indicate that natural gas processing plants that treat and process natural gas before moving it into the interstate natural gas transmission system may be particularly vulnerable to inundation than other forms of critical energy infrastructure. Under certain SLR assumptions, as much as six Bcfd (eight percent of all U.S. natural gas processing capacity) could be inundated. More extreme SLR exposure assumptions result in greater levels of energy infrastructure capacity exposure including as much as 39 percent of all U.S. refining capacity based on current operating levels. This research and its results show that while fossil fuel industries are often referenced as part of the climate change problem, these industries will likely be more than proportionally exposed to the negative impacts of various climate change outcomes relative to other industrial sectors of the U.S. economy. This has important implications for the U.S. and global energy supplies and costs, as well as for the U.S. regional economies reliant on coastal energy infrastructure and its supporting industries. 展开更多
关键词 GULF COAST Energy Infrastructure sea-level RISE CLIMATE change Natural Gas Processing REFINING Power Generation
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Magnetic susceptibility variations of carbonates controlled by sea-level changes——Examples in Devonian to Carboniferous strata in southern Guizhou Province,China 被引量:10
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作者 张世红 王训练 朱鸿 《Science China Earth Sciences》 SCIE EI CAS 2000年第3期266-276,共11页
This paper presents magnetic susceptibility results of 578 samples from three De-vono-Carboniferous carbonate successions in the Yangtze Block. They indicate that the magnetic susceptibility variations in carbonates a... This paper presents magnetic susceptibility results of 578 samples from three De-vono-Carboniferous carbonate successions in the Yangtze Block. They indicate that the magnetic susceptibility variations in carbonates are controlled by ancient sea-level changes. It is particularly so if the supply of detrital materials was low, when the magnetic susceptibility was mainly controlled by the content of authigenic minerals. If the supply of detrital materials was high, the average susceptibility value would be higher, but there is still a correlation between susceptibility and sea-level curves. A sea level rise would lead to a decrease in the content of the detrital materials, and therefore to a decrease in the susceptibility values. On the top of HST, the uplift and exposure events may lead to elevated magnetic susceptibility values. Carbonate susceptibilities can therefore be considered as one of the environmental proxy data for the research of sequence stratigraphy. 展开更多
关键词 carbonate magnetic susceptibility sea-level change SOUTHERN Guizhou Province DEVONIAN Carboniferous.
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Sea-level changes and hydrothermal sedimentary mineralization of large-superlarge ore deposits among Sinian to Triassic in South China 被引量:5
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作者 陈多福 陈先沛 陈光谦 《Science China Earth Sciences》 SCIE EI CAS 2003年第z1期154-163,共10页
Among the Sinian to Triassic strata in South China, the stratiform, quasi-stratiform and lenticular metallic deposits in association with hydrothermal sedimentation mainly occur in the four periods: (1) the Sinian Dat... Among the Sinian to Triassic strata in South China, the stratiform, quasi-stratiform and lenticular metallic deposits in association with hydrothermal sedimentation mainly occur in the four periods: (1) the Sinian Datangpo interglacial period, (2) the early period of Early Cambrian, (3) the late period of Middle Devonian to early period of Late Devonian,and (4) the late period of Early Permian. The four mineralization periods all happened around the maximum flooding period in the third-order seal-level cycle during the ascending stage in the first-order sea-level cycle. The deep seawater layer, starved and non-compensatory basin, low sedimentary rate, and low energy and anoxic environment during the maximum flooding period are very suitable for the formation and preservation of large to superlarge hydrothermal sedimentary deposits. The maximum flooding period also coincided with the intensified regional tectonism, extensive deep magmatism and hydrothermal sedimentation, which provide, for the formation of large to superlarge hydrothermal sedimentary deposits through the rapid accumulation of hydrothermal sediments, the needed dynamics, ore-forming materials and favorable passway for hydrothermal fluids to enter the basin. 展开更多
关键词 sea-level change SUPERLARGE hydrothermal SEDIMENTARY deposits SINIAN to Triassic South China.
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Sedimentary Evolution of the Holocene Subaqueous Clinoform off the Southern Shandong Peninsula in the Western South Yellow Sea 被引量:20
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作者 QIU Jiandong LIU Jian +4 位作者 SAITO Yoshiki YANG Zigeng YUE Baojing WANG Hong KONG Xianghuai 《Journal of Ocean University of China》 SCIE CAS 2014年第5期747-760,共14页
Based on the stratigraphic sequence formed since the last glaciation and revealed by 3000 km long high-resolution shallow seismic profiles and the core QDZ03 acquired recently off the southern Shandong Peninsula, we a... Based on the stratigraphic sequence formed since the last glaciation and revealed by 3000 km long high-resolution shallow seismic profiles and the core QDZ03 acquired recently off the southern Shandong Peninsula, we addressed the sedimentary characteristics of a Holocene subaqueous clinoform in this paper. Integrated analyses were made on the core QDZ03, including sedimentary facies, sediment grain sizes, clay minerals, geochemistry, micro paleontology, and AMS 14 C dating. The result indicates that there exists a Holocene subaqueous clinoform, whose bottom boundary generally lies at 15–40 m below the present sea level with its depth contours roughly parallel to the coast and getting deeper seawards. The maximum thickness of the clinoform is up to 22.5 m on the coast side, and the thickness contours generally spread in a banded way along the coastline and becomes thinner towards the sea. At the mouths of some bays along the coast, the clinoform stretches in the shape of a fan and its thickness is evidently larger than that of the surrounding sediments. This clinoform came into being in the early Holocene(about 11.2 cal kyr BP) and can be divided into the lower and upper depositional units(DU 2 and DU 1, respectively). The unit DU 2, being usually less than 3 m in thickness and formed under a low sedimentation rate, is located between the bottom boundary and the Holocene maximum flooding surface(MFS), and represents the sediment of a post-glacial transgressive systems tract; whereas the unit DU 1, the main body of the clinoform, sits on the MFS, belonging to the sediment of a highstand systems tract from middle Holocene(about 7–6 cal kyr BP) to the present. The provenance of the clinoform differs from that of the typical sediments of the Yellow River and can be considered as the results of the joint contribution from both the Yellow River and the proximal coastal sediments of the Shandong Peninsula, as evidenced by the sediment geochemistry of the core. As is controlled mainly by coactions of multiple factors such as the Holocene sea-level changes, sediment supplies and coastal dynamic conditions, the development of the clinoform is genetically related with the synchronous clinoform or subaqueous deltas around the northeastern Shandong Peninsula and in the northern South Yellow Sea in the spatial distribution and sediment provenance, as previously reported, with all of them being formed from the initial stage of the Holocene up to the present. 展开更多
关键词 subaqueous clinoform HOLOCENE Yellow Sea Shandong Peninsula Yellow River PROVENANCE sea-level change sedimentary
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Stable carbon and oxygen isotopic compositions of carbonates in middle Mesoproterozoic Wumishan Formation and sea-level change 被引量:8
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作者 Renwei Li Jinshi Chen Shukun Zhang 《Chinese Science Bulletin》 SCIE EI CAS 1999年第23期2130-2136,共7页
δ13C of dolostones from the Wumishan Formation (1 310-1 207 Ma) in the Ming Tombs area near Beijing ranges from - 1.5 to 1.5‰ (PDB), and generally, the δ18O ranges from - 4 to - 5‰ (PDB). The secular variation of ... δ13C of dolostones from the Wumishan Formation (1 310-1 207 Ma) in the Ming Tombs area near Beijing ranges from - 1.5 to 1.5‰ (PDB), and generally, the δ18O ranges from - 4 to - 5‰ (PDB). The secular variation of stable carbon isotopic compositions is cyclic. δ13C displays positive shifts from a sequence boundary to 1.5 per mil (PDB), then 展开更多
关键词 carbon and OXYGEN ISOTOPES Mesoproterozoic. sea-level change.
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Sedimentary Evolution and Transgressions of the Western Subei Basin in Eastern China since the Late Pliocene 被引量:9
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作者 CHENG Yu LI Xiangqian +6 位作者 SHU Junwu BAI Shibiao ZHAO Zengyu ZHANG Xiangyun GUO Gang ZHANG Ping LIN Jingxing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第1期155-166,共12页
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
关键词 FORAMINIFERA and OSTRACODS sea-level change TRANSGRESSION Subei Basin
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