检索结果-南通市图书馆

Isotopic compositions of small shelly fossil Anabarites from Lower Cambrian in Yangtze Platform of South china: Implications for palaeocean temperature

引用

Progress in Natural Science:Materials International 2007年第10期17卷 1185-1191页

作者： Chen Yongquan1,2. Jiang Shaoyong1, Ling Hongfei1, Yang Jinghong1 and Wan Defan3(1. state key Laboatory for {2. Deposits Research and Center for Marine Geochemistry Research, Department of Earth Sciences, Nanjing university, Nanjing 2.0093, china 2. Tarim Oilfield Company Exploration & Development Research Institute, Ku’erle 841000, china 3. Institute of {2. resources, Chinese Academy of geological Sciences, Beijing 100037, china) state key Laboatory for {2. Deposits Research and Center for Marine Geochemistry Research Department of Earth Sciences Nanjing University Nanjing 210093 China arim Oilfield Company Exploration & Development Research Institute Ku’erle 841000 China Institute of mineral resources Chinese Academy of Geological Sciences Beijing 100037 China

Anabarites belong to small shelly fossils (SSF), which occur widely in the Lower Cambrian strata of Yangtze Platform in South china. They are phosphate shell in composition and represent the earliest stage of the Cambrian bioradiation of Bilateria, the so-called "Cambrian Explosion". In this study, we attempted to separate Anabarites fossils from Lower Cambrian dolostones, and we obtained samples of both the fossils (SSF) and the granular phosphates (GP). Isotopic analyses were performed on samples of SSF, GP, and matrix dolostone (DH-2.). The results showed that the δ30Si values of the quartz filling in fossils celoms, and the siliceous materials in granular phosphates are -0.6‰ and -0.7‰, which is different from normal sedimentary siliceous rocks from the Lower Cambrian strata (0—0.7‰) as reported by Li et al., but is consistent with the data for siliceous rocks and cherts of submarine hydrothermal origin. It is likely that a later hydrothermal replacement could have taken place in the SSF-bearing sedimentary rocks. The oxygen isotope values of the phosphate of SSF and GP are 16.8‰ and 17.0‰, respectively. These are significantly higher than the Neoproterozoic phosphate ores (10.9‰—13.9‰) as reported by Ling et al., hence, late diagenesis and hydrothermal replacement may not have caused a significant change in the oxygen isotope compositions of the small shelly fossils, and the calculated temperatures (2..4—2..3℃) for palaeo-seawater using a SSF phosphate oxygen isotope thermometer are therefore considered here as the upper limit of seawater temperature in the Early Cambrian ocean of the Yangtze Platform.

关键词： Anabarites oxygen isotope silicon isotope paleo-temperature.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

LA-ICP-MS U-Pb Zircon Geochronology,Geochemistry and Kinetics of Wenquan Ore-Bearing Granites from Western Qinling,china

引用

矿物学报 2009年第S1期29卷 298-300页

作者： CAO Xiao-feng1,2.Lü Xin-biao1,2.CHEN Chao2.LIU Shen-tai2.ZHANG Ping2.SU Yu-yun2.MEI Wei2.ZHANG Bin3(1. state key Laboratory of {2. Processes and mineral resources,china university of geosciences,Wuhan 430074,china 2. china Resource Department,china university of geosciences,Wuhan 430074,china)

As we know there is a famous East Qinling-Dabie molybdenum belt in china,where many molybdenum deposits located such as super giant Jinduicheng,Sandaozhuang,Shangfanggou and Nannihu molybdenum deposits(Li,2.08) ;The molybdenum mineralization in the East Qinling-Dabie belt clusters into three groups or mineralization pulses:2.3-2.1,148-138 and 131-112.Ma(Mao et al,2.08).

关键词： Pb LA-ICP-MS U-Pb Zircon Geochronology,Geochemistry and Kinetics of Wenquan Ore-Bearing Granites from Western Qinling,china ICP MS

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

On the Flood Disasters in the Lower Jingjiang Reaches: Grey Prediction Model and Application

引用

Chinese Journal of Population,resources and Environment 2005年第3期3卷 37-41页

作者： Yang Guifang 1, Huang Changsheng 2. Yin Hongfu 2.& Li Chang’an 2.1 state key Laborary of Estuarine and Coastal Research, East{2. Normal university, Shanghai 2.0062.{2. 2.5}, Wuhan 430074,{2. state key Laborary of Estuarine and Coastal Research East China Normal University Shanghai 200062 China china university of {2. Wuhan 430074 China

In the light of the historical substantial data (covering a 70-year period) collected in the Lower Jingjiang segment and aided by topological grey method, here we attempt to characterize the occurrence and future trend of flood calamities in the study area. Our findings indicate that overall the high-frequent flood disasters with middle to lower damage prevail at present. A series of dramatic flood waves will appear in the years of 2.16, 2.2., 2.30 and 2.42. particularly a destructive flood will occur between 2.41 and 2.45 in the Lower Jingjiang reaches. Typical of sensitive response to flood hazards in close association with its special geographical location, the lower Jingjiang segment hereby can reflect the development trend of floods in the middle Yangtze reaches. According to the results, a good fitness was revealed between the prediction and practical values. This actually hints that the topological grey method is an effective mathematical means of resolving problems containing uncertainty and indetermination, thus providing valuable information for the flood prediction in the middle Yangtze catchment.

关键词： flood hazard prediction occurrence future trend grey system method lower jingjiang reaches

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

Phylogeography of regional fauna on the Tibetan Plateau: A review

引用

Progress in Natural Science:Materials International 2009年第7期19卷 789-799页

作者： Shujuan Yanga, Hailiang Dongb,c, Fumin Lei d a state key Laboratory of {2. Processes and mineral resources, china university of geosciences, Beijing 100083, china b Geomicrobiology Laboratory, china university of geosciences, Beijing 100083, china c Department of Geology, Miami university, Oxford, OH 45056, USA d Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, china [a]state key Laboratory of {2. Processes and mineral resources China University of Geosciences Beijing 100083 China [b]Geomicrobiology Laboratory China University of Geosciences Beijing 100083 China [c]Department of Geology Miami University Oxford OH 45056 USA [d]Institute of Zoology Chinese Academy of Sciences Beijing 100101 China

The studies of uplift and glaciations of the Tibetan Plateau are summarized, and a series of recent case studies of the endemic species based on DNA sequences are detailed. In general, these molecular data show that all the organisms originated from Early Pliocene to Late Miocene, and then multi-stages of divergence/speciation occurred within each taxa following their original occupation on the plateau, mainly as a result of periodic glacial cycles and geographic isolation. The regional fauna may have undergone several range contractions and expansions during the Pleistocene glaciations. However, the population expansion and refugia may vary in space, time, and extent. The regional fauna of the Tibetan Plateau may be combinations of ancient movement from adjacent zoogeographical regions, speciation in situ, and postglacial colonization from adjacent areas. Geomorphic and climatic changes on the plateau definitely have a remarkable influence on the regional and adjacent biogeographic patterns, and the mechanism is very complex.

关键词： Divergence Refugia Postglacial colonization Phylogeography Regional fauna Tibetan Plateau

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Syndepositional Fault Controlling on Depositional Filling of the Third Member of Shahejie Formation in Beitang Sag

引用

Journal of Earth Science 2009年第6期20卷 949-958页

作者：黄传炎王华肖敦清陈思王家豪廖远涛 Faculty of Earth resources China University of Geosciences state key Laboratory of {2. Processes and mineral resources China University of Geosciences key Laboratory of Tectonics and Petroleum resources of Ministry of Education China University of GeosciencesWuhan Research Institute of Exploration and Development PetroChina Dagang Oilfield Company

In the continental lake basin whose structures were extraordinarily active, tectonism is an important factor in controlling the sequence and the depositional filling of the basin. This article reports the assemble patterns of syndepositional fault in the third member of Shahejie （沙河街） Formation in Beitang （北塘） sag. The results show that the comb-shape fracture system and the fracture transformation zone were developed in Beitang sag. These assemble patterns obviously controlled the sand-body and spatial distribution of sedimentary system. However, the steep slope belt of fault terrace, the multistage slope belt and the low uplift gentle slope belt controlled the development of sequence styles. Analyses of the spatial-temporal relationship of the assemble pattern of syndepositional faults and the sedimentary system help predict the favorable exploration zone.

关键词： Beitang sag syndepositional fault structural slope break zone the third member of Shahejie Formation.

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

High-resolution dating of Co-rich crusts: A comparative study using the methods of orbital pacing and ^(2.0)Th_(ex)/^(2.2.Th dating

引用

Science china Earth Sciences 2009年第4期52卷 484-488页

作者： HAN XiQiu1,2. QIU ZhongYan1,2.3, MA WeiLin1,2.& QIAN JiangChu1,2.1 key Laboratory of Submarine geosciences, {2. Oceanic Administration, Hangzhou 310012. china 2.Second Institute of Oceanography, {2. Oceanic Administration, Hangzhou 310012. china 3 Department of Earth Sciences, Zhejiang university, Hangzhou 31002., china key Laboratory of Submarine geosciences State Oceanic Administration Hangzhou 310012 China Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China Department of Earth Sciences Zhejiang University Hangzhou

Due to their slow growth rates, seamount Co-rich crusts are very difficult to date with high resolution and precision. This paper is to test the use of orbital pacing on the growth profile of crusts to determine high-resolution age and growth rate. Crust CB14 from the central Pacific Ocean was selected for this study. We first examined the growth pattern in detail under a reflected-light microscope and ascertained that the growth environment was stable for the sub-layer 1 (0-3 mm). We then used electron micro-probe line-scanning to obtain elemental profiles. The pattern of the power spectrum analysis of the Al-profile revealed that there are significant cycles of 113.9, 87.8, 51.5, 42.2.and 2..8 μm. These cycles correspond to the Milankovitch cycles of 53.1, 41, 2., 19.7 and 12.ka, respectively, and yield the growth rate of about 2.14 mm/Ma and an age of about 1.40 Ma for the boundary between the sub-layer 1 and sub-layer 2. We also used a drilling machine with a numerically controlled drive to obtain high-resolution samples at 0.1mm intervals, and used the 2.0Thex/2.2.h method to date the samples. For the uppermost 1.3 mm, the growth rate was about 2.15 mm/Ma, and the age for the layer at the depth of 3 mm was about 1.40 Ma, which coincides perfectly with the results obtained from orbital pacing. Thus, it is considered that orbital pacing is a new and effective method to determine the growth rate of the seamount Co-rich crust. This method is applicable for establishing a high-resolution age frame for the crusts of the world's oceans.

关键词： seamount Co-rich crust Milankovitch cycles 2.0Thex/2.2.h dating growth rates of Mn-crusts central Pacific Ocean

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

Lithosphere types in North china:Evidence from geology and geophysics

引用

Science china Earth Sciences 2005年第11期48卷 1809-1827页

作者： QIU Ruizhao1,2. DENG Jinfu3, ZHOU Su3, LI Jinfa4, XIAO Qinghui1,5, WU Zongxu6 & LIU Cui3 1. Institute of Geology, Chinese Academy of geological Sciences, Beijing 100037, china 2. Development and Research Center, china geological Survey, Beijing 100037, china 3. china university of geosciences, Beijing 100083, china 4. china university of geosciences, Wuhan 430074, china 5. Information Center of Ministry of Land and resources, Beijing 100812. china 6. Institute of Geology, {12. Seismological Bureau, Beijing 10002., china 1. Institute of Geology Chinese Academy of Geological Sciences 100037 Beijing China 2. Development and Research Center China Geological Survey 100037 Beijing China 3. china university of geosciences 100083 Beijing China 4. china university of geosciences 430074 Wuhan China 5. Information Center of Ministry of Land and resources 100812 Beijing China 6. Institute of Geology State Seismological Bureau 100029 Beijing China

On the basis of the characteristics of geology and geophysics in North china, three types of lithosphere, namely, the cratonic, the orogenic and the rift lithospheres can be classified. In terms of petrological method (based on the information from Precambrian rock assemblages, igneous activities, deep-seated enclaves, etc.) and the relationship between seismic velocity and rock compositions, the crust-mantle petrological and chemical structure models can be set up. Researching results indicate that the geology and geophysics of North china platform bears the similar characteristics in comparison with those of the global typical cratons. The Eerduosi(Ordos) block located in the west of the North china Platform is a remnant of cratonic lithosphere after the North china platform had undergone “activation” in Mesozoic and “reconstruction” in Cenozoic times. The continental crust consists mainly of TTG rock assemblage while the subcontinental lithosphere mantle mainly consists of strongly depleted harzburgite. The craton was finally formed in late Archaean and early Proterozoic, and has been kept in stability up to present; its crustal-mantle petrological structures of lithosphere can be set up as a reference for the study of North china craton and even Sino-Korean craton. In the Mesozoic period, the middle and east areas of North china platform were activated in the Yanshanian orogenic process, the continental crust was reformed by material and heat-transfer of convective mantle and the original crustal TTG component was reconstructed to be granitic crust, and the subcontinental lithosphere man- tle was replaced by the Yanshanian harzburgite-lherzolite. The Yanshan-Taihang Mountains were the remnants of orogenic lithosphere after the rifting in eastern North china in Cenozoic. The present thickness of continental crust and lithosphere in the Yanshan-Taihang Mountains is not equal to their thickness during the Yanshanian orogenic movement because they had undergone the

关键词： lithospheric types,evidence of geology and geophysics,crust-mantle petrological structure,deep process

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

Discovery of double-peaking potassic volcanic rocks in Langshan Group of the Tanyaokou hydrothermal- sedimentary deposit, Inner Mongolia, and its indicating significance

引用

Science china Earth Sciences 2005年第6期48卷 822-833页

作者： PENG Runmin1, ZHAI Yusheng1, WANG Zhigang2.& HAN Xuefeng2.1. key Laboratory of Lithospheric Tectonics and Lithoprobing Technology, Ministry of Education, china university of geosciences, Beijing 100083,{2. 2. Inner Mongolia geological Prospecting Institute, Ministry of Chemical Industry, Hohhot 010074,{2. Correspondences should be addressed to Peng Runmin 1. key Laboratory of Lithospheric Tectonics and Lithoprobing Technology Ministry of Education China University of Geosciences 100083 Beijing China 2. Inner Mongolia geological Prospecting Institute Ministry of Chemical Industry 010074 Hohhot China

It is revealed that the protolith of gray-light brown potash-feldspar-leucogranulites and granulites in the 2.d formation of the LG in Tanyaokou deposit are quartz kerotophyre of synsedimentary eruption based on the following facts and features: (1) The rocks look compact and homogeneous without obvious crystals with naked eyes; (2. they contain blastoporphyritic or glomeroporphyritic and blasto-crystalloclastic crystals consisting of quartz with wavy extinction and albite with obvious alteration and deformation; (3) they also contain radiated and fibrous blasto-microspherulitic texture and swallow-tailed bifurcate and blasto-hollow-skeleton crystal texture, representing the rapid cooling characteristic of the magma during submarine volcanic eruption; (4) the major chemical compositions of the rocks are: SiO2.= 70.80%―76.00%, K2. (4.83%―6.2.%)>Na2.(2.78%―3.80%), and K2.+Na2. = 8.63%―9.00%; and (5) their petro-chemical diagrams indicate that they are volcanic rocks. Together with the characteristic that they occur in the same sequence with potassic spilite (SiO2.= 46.12.―50.68%, K2. = 4.2.%―5.93%>Na2. = 2.15%―3.14%, K2.+Na2. = 6.51%―8.08%), it can be confirmed that the vol-canics occurring in the 2.d Formation of the LG in Tanyaokou district are double-peaking potas-sic volcanic rocks. The discovery, together with the tuffs with ore minerals and the distribution of lead isotopic as well as the value of Co/Ni of pyrites >1 showing the obvious endogenic metali-zation, can prove that the Tanyaokou deposit is an untypical SEDEX-type deposit formed in the extension fault basin in the Mesoproterozonic aulacogen of the northern margin of the North{2. Platform, and its metallogenesis is related to the synsedimentary volcanic activities and the hydrothermal exhalation, and both the ore-forming material source and volcanics came from mantle or lower crust. These facts mentioned above, together with the meta-volcanic rocks (double-peaking) found in the Dongshengmiao and Huog

关键词： extensional rift basin, double-peaking potassic volcanic rocks, Mesoproterozoic, the 2.d formation of LG, Tanyaokou deposit, 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

Identification of 3.5 Ga detrital zircons from Yangtze craton in south china and the implication for Archean crust evolution

引用

Progress in Natural Science:Materials International 2006年第6期16卷 663-666页

作者： LIU Xiaoming, GAO Shan, LING Wenli, YUAN Honglin and HU Zhaochu (National key Laboratory of geological Processes and {2. resources, Faculty of Earth Sciences, china university of geosciences, Wuhan 430074, china key Laboratory of Continental Dynamics, Department of Geology, Northwest university, Xi' an 710069, china) [a]National key Laboratory of geological Processes and {2. resources Faculty of Earth Sciences China University of Geosciences Wuhan China [b]key Laboratory of Continental Dynamics Department of Geology Northwest University China

The LA-ICP-MS U-Pb dating of hundreds of detrital zircon grains from the Sinian sandstones of Liantuo formation and tillites of Nantuo formation at Sanxia area in Yichang identified 3319-3508 Ma zircon grains. Their 2.7Pb/2.6Pb and 2.6Pb/2.8U ages show excellent agreement (concordia degree 99%-100% ). Their CL images exhibit well-developed oscillatory zoning and the Th/U ratios are within 0.46-0.76, implying that they are igneous zircons which formed during middle-early Archean. These zircons are the oldest ones discovered in Yangtze craton until now. However, the detrital zircons with ages older than 3. 3 Ga in the metamorphic rocks of Kongling group were not found by further investigation, which suggests the presence of crust older than high-grade metamorphic Kongling terrain in Yangtze craton.

关键词： early Archean detrital zircon zircon dating Yangtze craton.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Clay Rocks around Permian-Triassic Boundary at Daxiakou Section in Hubei Province,china

引用

Journal of Earth Science 2009年第6期20卷 909-920页

作者：张素新袁鹏赵来时童金南杨浩于吉顺史玉芳 state key Laboratory of {2. Processes and mineral resources China University of Geosciences Faculty of Earth Sciences China University of Geosciences state key Laboratory of {2. Processes and mineral resources China University of Geosciences

We studied the clay rocks around the Permian-Triassic boundary at the Daxiakou （大峡口） Section in Xingshan （兴山）, Hubei （湖北） Province, china. All clay rocks are predominated by illitemontmorillonite （I/M） mixed-layer minerals, and high-temperature hexagonal bipyramid （HB） quartz and pyrite are contained in different abundances. Clay microspheres are even found in some beds. The results show that volcanic activity was very frequent in this area or in the neighboring areas during the Permian-Triassic transition though the intensity of eruption and the position of the eruption center might have varied during the period. The frequent volcanic activity should be at least one of the leading events to cause the momentous turnover of biota and the ecosystem during the great Permian-Triassic transition.

关键词： volcanic activity Permian-Triassic boundary Daxiakou Section Hubei Province.

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：