检索结果-南通市图书馆

Ancient Changjiang channel system in the East china Sea continental shelf during the last glaciation

Science china Earth Sciences 2005年第11期48卷 1972-1978页

作者： LI Guangxue1,2. LIU Yong1, YANG Zigeng3, YUE Shuhong4. YANG Wenda5 & HAN Xibin1 1. College of Marine Geo-science, Ocean University of china, Qingdao 2.6003, china 2. Shandong Key Laboratory of Sea Floor Resource and Exploration Technique, Qingdao 2.6003, china 3. Qingdao institute of Marine Geology, Qingdao 2.6071, china 4. College of Marine Environment, Ocean University of china, Qingdao 2.6003, china 5. First Survey Team of Marine Geology, Shanghai bureau of Petroleum, Shanghai 2.12.8, china 1. College of Marine Geo-science Ocean University of China 266003 Qingdao China 2. Shandong Key Laboratory of Sea Floor Resource and Exploration Technique 266003 Qingdao China 3. Qingdao institute of Marine Geology 266071 Qingdao China 4. College of Marine Environment Ocean University of China 266003 Qingdao China 5. First Survey Team of Marine Geology Shanghai Bureau of Petroleum 201208 Shanghai China

Based on the data of high-resolution seismic profiles, an ancient river channel sys-tem of the last glaciation occurred along the Zhedong and Xihu depression in the southeast of Hupijiao rise. The distribution of the channel fill system shows that the ancient Changjiang River went through the Changjiang depression into the low land plain of the outside continental shelf during the low sea level cycle of the last glaciation. The big channel fill into Okinawa Trough is not found due to the depletion of the river kinetic energy in the low land plain. The river discharge dispersal was of an important role to the dilution of the northern Okinawa Trough sea at that time. Six ancient river channel systems (A―F), which are main distributaries of ancient Changjiang in the East china Sea continental shelf during the last glaciation, may be buried off the modern Changjiang estuary. The distribution of these channels coincides with the zonal elevations in the sea floor.

关键词： last glaciation, continental shelf plain, Changjiang River, ancient channel fill

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Some Evidence for a Possible Extraterrestrial Event at/near Permian-Triassic Boundary

引用

Journal of china University of Geosciences 2002年第2期13卷 151-156页

作者： Xu Daoyi institute of Geology, china {2. bureau, Beijing 10002. institute of Geology China Seismological Bureau Beijing 100029

A selection of evidence, including a carbon isotopic excursion, iridium anomaly, fullerenes (C 60 and C 70 ) with trapped noble gases, microspherules and shocked quartz, is discussed in this paper. All the evidence in hand favors the hypothesis that the PTB event was probably related to an extraterrestrial cause, and the impact would lead to great physical change, including large volcanic eruptions on the earth's surface. The ET markers for the CTB event could be considered only as an example, and cannot be taken as a unique standard of an ET event.

关键词： Permian Triassic boundary extraterrestrial event iridium anomaly carbon isotopic excursion.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Gradient analysis of landscape spatial and temporal pattern changes in Beijing metropolitan area

引用

Science china(Technological Sciences) 2010年第S1期53卷 91-98页

作者： YANG YeTao1,ZHOU QiMing2.GONG JianYa3 & WANG YingYing4.1 institute of geophysics and Geomatics,{2. University of Geosciences,Wuhan 4.0074.{2. 2.Department of Geography,Hong Kong Baptist University,Hong Kong 3 State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan 4.0074.{2. 4.Hubei Provincial bureau of Meteorology,Wuhan 4.0074.{2. 1. institute of geophysics and Geomatics China University of Geosciences Wuhan 430074 China2. Department of Geography Hong Kong Baptist University Hong Kong China3. State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan 430074 China4. Hubei Provincial Bureau of Meteorology Wuhan 430074 China

The gradient based landscape metrics analysis is now widely used to study the landscape pattern changes in respond to the *** order to discover the trend of spatio-temporal changes in Beijing metropolitan area during the past 15 years,several landscape metrics are computed using a moving window along a 96 km long transect across Beijing metropolitan area from west to ***,the spatial extent of sub-landscape,which is determined by the moving window’s size,is profoundly *** results show that the metrics varies smoothly and regularly along the selected transect when the window size is greater than 6 km×6 km,and irregularly fluctuated for the smaller window size,that the spatial and temporal landscape characteristics of Beijing city match the hypothetical framework of spatio-temporal urban sprawl in the form of alternating processes of diffusion and coalescence well,and that some new trends of the urban sprawl style in Beijing metropolitan area,such as leap-frog manner,are also detected by the gradient landscape analysis.

关键词： gradient analysis landscape metrics spatio-temporal urban expansion multi-extent

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Lead isotopic characteristics of the Xikuangshan superlarge Sb deposit and their geological implications

引用

chinese Science Bulletin 1999年第S2期44卷 52-53页

作者： PENG Jiantang~1, HU Ruizhong~1 and ZOU Liqun~2.1. institute of Geochemistry, chinese Academy of Sciences, Guiyang 550002.{2. 2. Xikuangshan Mining bureau, Lengshuijiang 4.7502.{2. institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Xikuangshan Mining bureau Lengshuijiang 417502 China

THE Xikuangshan Sb ore deposit located in the central part of Hunan Province, china, is the only superlarge Sb deposit so far reported in the world, and is titled as the antimony capital of the world. The strataexposed in the Xikuangshan orefield are only Devonian to Permian Series. Except for a lamprophyre dykeseen in the eastern part, no igneous rocks outcrop within or around the mining district. Orebodies occurdominantly in the Devonian Shetianqiao Formation （D3s） and subordinately in the Qiziqiao Formation（D2./sub>q）. The orebodies usually appear stratiform and stratoid in shape and are rather constant in boththickness and grade. The compositions of ores are simple. The metallic mineral is stibnite and the gangueminerals include quartz and calcite, with minor amounts of fluorite, barite and secondary gypsum. Theores are dominated by the quartz-stibnite type, the quartz-calcite-stibnite type and the

关键词： lead isotope Xikuangshan superlarge Sb deposit Hunan.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Geoscience Transect from Xiangshui,Jiangsu Province to Mandal,Inner Mongolia

引用

Acta Geologica Sinica(English Edition) 1992年第1期66卷 1-21页

作者： Ma Xingyuan Liu Changyuan Liu Guodong Jiang Minxi institute of Geology,State seismological {2.,Beijing Geophysical Exploration Pafrty,State seismological {2.,Zhengzhou. 2.0} of Geology State Seismological Bureau Beijing. 3Geophysical Exploration Party State Seismological Bureau Zhengzhou.

The Xiangshui to Mandal geoscience transect, which has a total length of 1,2.0 km, extends diagonally,from SE to NW, across the Sino-Korean plate and its ancient continental margin, passing through nine tectonicunits: the Subei-Jiaonan terrane, West Shandong block, North china rift basin, Taihang-Wutai block, Ordosblock, Hu-Bao (Hohhot-Baotou) Basin, Yinshan block and Inner Mongolian fold system. The graphic display of the transect is compiled according to the Guidelines for the Global GeoscienceTransect (GGT) Project on the basis of an integrated study of all available geological, geochemical andgeophysical data, thus bringing light to the process of cratonization of the Sino-Korean plate and its relation-ship with the transitional zone of the ancient continental margin, and the features of intraplate structures pro-duced by subsequent tectonic modifications and intraplate dynamics.

关键词： The Geoscience Transect from Xiangshui Jiangsu Province to Mandal Inner Mongolia

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

THE GLOBAL TECTONIC SYSTEMS AND A LATITUDINAL MOUNTAIN-PLATEAU CHAIN ON THE NORTH HEMISPHERE

引用

地学前缘 2000年第S1期7卷 344-345页

作者： Ma Zongjin(institute of Geology,china {2. bureau,Beijing 10002.,china)

Three global tectonic systems that formed since the middle Jurassic (160Ma ago)are outlined based on the global map of the Cenozoic and Mesozoic tectonics edited by Ma Zongjin et al.(1996).They are the circum\|Pacific tectonic system,the mid\|ocean ridge tectonic system and the intra\|continental tectonic system of the north *** map shows that about 80% of the total length of the continental orogens are concentrate on the north hemisphere of the earth,of which a latitudinal mountain\|plateau chain occur within a zone between north latitude 2.°and 50°.Seismic and volcanic activities demonstrate that the intracontinental tectonic system on the north hemisphere is still *** distribution of the continental deep\|focus earthquakes and almost ultra high\|pressure rock found so far over the World,that are assumed both related to recent or previous deep subduction of continent,along with this *** latitudinal mountain\|plateau chain is subdivided into four active tectonic region of Qinghai—Xizang(Tibet),Iranian,eastern mediterranean and North American,both characterized by an individual similar mountain\|plateau\|basin structure with major active boundaries or controlling faults (Fig.1).These active regions are all close to primary dynamic boundaries of continent\|continent *** of source mechanisms shows that regional tectonic stress field in these regions are dominated by a nearly NS or NNE—SSW direction compression corresponding to a local plate motions and a global compressive *** between the formation of the continental latitudinal mountain\|plateau chain on north hemisphere and the oceanic plate tectonics is discussed using the information of the “Map of Magnetic Lineations of the World’s Ocean Basins (Cande et al.,1989)”and the Cenozoic and Mesozoic tectonic evolution in the *** 4. accretion units formed during 6 accretion stages of the ocean spreading in three chief oceans (the Pacific,the India and th

关键词： global asymmetrical system geodynamics mountain\| plateau chain seismotectonic system latitudinal tectonic zone

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Application of rock creep experiment in calculating the viscoelastic parameters of earth medium

引用

Science china Earth Sciences 2006年第5期49卷 492-498页

作者： SHI Xingjue1, WEN Dan1, BAO Xueyang1, LI Chengbo1 & HUANG Yun2.1. School of Earth and Space Sciences, University of Science and Technology of china, Hefei 2.002., china 2. {2. bureau of Jiangsu Province, Nanjing 2.0014. china 1. School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China 2. seismological bureau of Jiangsu Province Nanjing 210014 China

Based on the rock creep experiment, the data of aftershock sequence and post-earth- quake deformation are used to estimate the viscosity of crust medium near earthquake focus. Firstly 9 samples that belong to 3 kinds of rock are conducted in creep experiment under constant pressure to obtain the creep curves directly. Inversion results show that the standard linear model is the best one to present the earth medium. It exhibits obvious elasticity within a short time, while it exhibits obvious rheology within a long time. The relationship between element module μ 2.and the whole module μ of standard linear model or the module of real earth medium is calculated and analyzed. On the basis of μ 2.= 2. μ, the sequence of aftershock of Gonghe earthquake in Qinghai Province is analyzed and the relationship between accumulated released strain and the time is obtained, which, combined with the creep experiment results, is used to estimate the viscosity of crustal medium in this area. The measured vertical deformation after the same earthquake also is combined with the creep experiment results, then it is used to calculate the relaxation time and viscosity through three different methods respectively, i.e. inversion of Kelvin model, difference method of deformation and viscoelastic dislo- cation theory. The viscosity of crustal medium in 32.km depth of earthquake focus of Gonghe area deduced from the different data and methods is about 1019 Pa·s, which is the same as the research results by other authors at home and abroad.

关键词： creep experiment, aftershock sequence, post-earthquake deformation, crustal viscosity.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

How Much Knowledge Has Been Obtained from an Earthquake?A Survey of seismological Publications

引用

Earthquake Research in china 2000年第4期14卷 88-98页

作者： Su Xiaolan, Zhu Chuanzhen,Wu Zhongliang and Huang Jinginstitute of geophysics,{2. seismological {4., Beijing 100081,{2. institute of geophysics China Seismological Bureau Beijing 100081 China

We analyzed the International Seismoogical Center(ISC)catalogue of seismologil publicationsfrom 1980 to 1995 to investigate how much infonformation provided by an earithquake hes beenutilized to obtain a better undertanding of earthauakes and selsmic *** sekect the ISCbulletin which has a wider coverage of seismological journals and languages than the ScientificCitation Index(SCI),so that there is less regional or language bias in the *** earth-quakes in the catalogue span the period from 1975 to *** which have direct relationwith an earthquake as defined by the ISC catalogue range from 1 to 10~2.in order of *** logarithm of the maximum number of papers on an earthquake is shown to be prop-ortional to the magnitude of the earthquake,which provides a possibility to define a“normali-zed impact strength”of an earthquake,so that earthquakes with different magnitudes can becompared with each *** span of the earthquakes with a certain“impact strengthlevel”

关键词： seismological publication Strategy of development ISC

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nd isotope as the tracer of seawater evolution of early Miocene in the eastern Pacific Ocean

引用

chinese Science Bulletin 2003年第B06期48卷 106-110页

作者： LIU Jihua~(1,2.3), CHEN Lirong~1, WANG Yingxi~4.& HAN Jianxiu~5 1. institute of Oceanology, chinese Acadcmy of ences, Qingdao 2.6071.{2. 2. Key Lab of Marine Sedimentology and Environmental Geology, First institute of Oceanograpgy, State Oceanic Administration, Qingdao 2.6061.{2. 3. Graduate School, chinese Academy of Sciences, Beijing 100039.{2. 4. Modern Analysis Center, Nanjing University. Nanjing 2.0093.{2. 5. Guangzhou Marine Investigation bureau, Guangzhou 510760.{2. 1. institute of Oceanology Chinese Academy of Sciences 266071 Qingdao China 2. Key Lab of Marine Sedimentology and Environmental Geology First Institute of Oceanograpgy State Oceanic Administration 266061 Qingdao China 3. Graduate School Chinese Academy of Sciences 100039 Beijing China 4. Modern Analysis Center Nanjing University 210093 Nanjing China 5. Guangzhou Marine Investigation bureau 510760 Guangzhou China

Fifty-six samples of nannofossil ooze were collected from Core PC5794.in the northern equatorial Pacific at 5 cm intervals. With the methods of mass spectrometer (VG354. and ICP, the Nd isotopic compositions (εNd(t)), Mn contents and Mg/Sr ratios of carbonate phase have been analyzed. CaCO3 contents of bulk sediments were obtained by dissolution of 0.5 mol/L HCl. Based on these data, the high-resolution εNd(t) profile of seawater in early Miocene with core depth(or time) have been established. The values of εNd(t) range from -6.2.to -2.97 and 4.fluctuation cycles existed during 2..06-2..02.Ma. 4.low εNd(t) values (about -6.4. correspond to high CaCO3 contents, which implicates that there were 4.cold epochs or 4.times of Antarctic Bottom Water activity. They occurred at the time of 2..06 Ma, 2..85 Ma,2..88 Ma and 2..2. Ma, respectively. High εNd(t) values correspond to the high Mn contents and high values of Mg/Sr ratio, which indicates the existence of 4.intense hydrothermal activity periods during 2..06-2. Ma, the durations of them are 4.05-2..98 Ma, 2..69-2..15 Ma, 2..74.2..37 Ma and 2..06-2..02.Ma, respectively.

关键词：同位素钕示踪原子海水演化中新世太平洋微化石分光计持续期海水样品

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on the 3-D Seismic Structures in Qinghai-Xizang Plateau

引用

Earthquake Research in china 2002年第1期16卷 27-38页

作者： Ding Zhifeng, He Zhengqin, Wu Jianping, and Sun Weiguoinstitute of geophysics,{2. seismological {4., Beijing 100081,{2. institute of geophysics China Seismological Bureau Beijing 100081 China

Based on the recording data from the analogue and broadband digital seismic stations in and around Qinghai-Xizang (Tibet) Plateau, the three dimensional (3-D) seismic velocity structures in Qinghai-Xizang Plateau were obtained by using the regional body wave tomography and surface wave tomography. The results from these two tomography methods have similar characteristics for P- and S-wave velocity structures in crust and upper mantle. They show that there are remarkable low velocity zones in the upper crust of Lhasa block in the southern Qinghai-Xizang Plateau and the lower crust and upper mantle of Qiangtang block in the northern Qinghai-Xizang Plateau. These phenomena may be related to the different steps of collision process in southern and northern Qinghai-Xizang Plateau.

关键词： Qinghai-Xizang Plateau Seismic tomography 3-D velocity structure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：