检索结果-南通市图书馆

geochronology and geochemistry of the Hegenshan ophiolitic complex:Implications for late-stage tectonic evolution of the Inner Mongolia-Daxinganling Orogenic Belt,China

Geochronology and geochemistry of the Hegenshan ophiolitic c...

引用

中国科学院地质与地球物理研究所2.08学术年会

作者： Laicheng Miao~(a,*),Weiming Fan~a,Dunyi liu~b,Fuqin Zhang~a,Yuruo Shi~b,Feng Guo~c a institute of geology and geophysics,Chinese Academy of Sciences,{2. {2.,China b {2. SHRIMP Center,{4. of geology,Chinese Academy of Geological Sciences,{2. 100037,China c Guangzhou {4. of Geochemistry,Chinese Academy of Sciences,Guangzhou 51064.,China

The Hegenshan ophiolite in the Inner Mongolian-Daxinganling Orogenic Belt(IMDOB),northern China,consists of several discontinuous blocks composed dominantly of serpentinized ultramafic rocks with subordinate cumulate gabbros,mafic lavas and dikes, intruded by younger granodiorite *** ultramafic rocks are highly depleted,serpentinized harzburgites with minor dunite,characterized by relative enrichment in large ion lithophile elements(LILE,e.g.,Ba and Rb) and light rare earth elements(LREE).They are interpreted to be oceanic mantle that has undergone extensive melt extraction and variable degrees of *** cumulate rocks consist mainly of gabbro and troctolite with LREE-depleted chondrite-normalized REE patterns showing significant positive Eu *** are enriched in LILE,depleted in Nb,and have high positiveε(t)(+8 to +11),suggesting derivation from a subduction-modified N-MORB-like *** gabbros and mafic dikes have essentially the same age(2.5±15 and 2.8±9 Ma,respectively). The mafic dikes have flat to LREE-depleted,chondrite-normalized REE patterns,are depleted in Nb,enriched in LILE and have NMORB-type Nd isotopic signatures(ε(t)=+8.1 to +10).The mafic lavas,erupted at 2.3±1 Ma,can be divided into two groups;one composed of strongly deformed metabasalts similar in chemical and Nd-Sr isotopic compositions to the mafic dikes,and the other composed of undeformed and unmetamorphosed basalts with oceanic island basalt(OIB)-like trace element signatures and Nd isotopic *** granodiorite dikes,which were intruded at 2.4.4.Ma,have LREE-enriched,chondrite-normalized REE patterns with no Eu *** abnormally highε(t) values(+6.3 to +6.8) and low I(0.704.2.to 0.704.0) suggest formation from melts derived from thickened oceanic crust during or shortly after closure of the Paleo-Asian *** structure,lithology and geochemistry of the Hegenshan ophiolite suggest that it is a Cordilleran-type body formed in a supra-subduction

关键词： Ophiolite geochronology Geochemistry Late Paleozoic Inner mongolia

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Precise U-Pb zircon dating at a scale of ＜5 micron by the CAMECA 12.0 SIMS using a Gaussian illumination probe

Precise U-Pb zircon dating at a scale of ＜5 micron by the C...

引用

中国科学院地质与地球物理研究所第11届（2.11年度）学术年会

作者： Yu liu,~aXian-Hua Li,~(*a)Qiu-Li Li,~aGuo-Qiang Tang~a and Qing-Zhu Yin~b ~aState Key laboratory of Lithospheric Evolution,{2. of {2. and {4.,Chinese Academy of Sciences,{4.,10002.,China. ~bDepartment of {2.,University of California Davis,One Shields Avenue,Davis,CA,95616,USA

Zircon is arguably the best,certainly the most commonly used mineral for U-Pb geochronology. Modern large-geometry secondary ion mass spectrometry(SIMS) has been routinely utilized for precise U-Pb zircon age determination at a lateral resolution of 10-30μ***,in situ U-Pb dating at a scale of ca.5μm scale or less for fine-grained zircons and/or zircon crystals with complex structural and chemical features is still a challenge to the geoscience *** we describe a method of precise U-Pb dating for zircons as young as the Jurassic age at a scale of up to2.0 *** mode primary O and O probes of ca 5.2.m and ca.4.5μm in diameter with beam intensities of～100 pA were obtained,respectively,by optimizing the primary *** ion optics was optimized to ensure a high Pb sensitivity in zircons,producing～2. cps/ppm/nA using O and～13 cps/ppm/nA using O(with oxygen flooding technique).As a demonstration of this method,three well-characterized zircon standards with a range of ages,AS3 (1099 Ma),Plesovice(377 Ma) and Qinghu(159.5 Ma),were *** demonstrate with these zircon standards that their ages could be determined with precision and accuracy of 1-2.using a spotgeochronology,because it has higher density and produces smaller craters on the target surface,with insignificant trade off in precision and accuracy of the final U-Pb *** U-poor minerals of younger ages,O might be preferred in order to generate sufficient Pb ions for measurement with minimal loss of spatial resolution.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

华北板内深部构造

引用

山西地震 2002年第4期 3-12页

作者：邢集善刘建华赵晋泉山西省地质勘查局物化院山西运城044004 中国科学院地质地球物理研究所北京100101 山西省地震局山西太原030002

华北板块的形成经历了早前寒武纪、燕山期及喜马拉雅期 3个主要构造发展期 ,由于华北板块自身运动及所受应力场的作用 ,加之上地幔岩石圈的不均一性等因素 ,在中、新生代形成许多特殊的板内构造块。综合应用地质、地球物理和地球化学的... 详细信息

华北板块的形成经历了早前寒武纪、燕山期及喜马拉雅期 3个主要构造发展期 ,由于华北板块自身运动及所受应力场的作用 ,加之上地幔岩石圈的不均一性等因素 ,在中、新生代形成许多特殊的板内构造块。综合应用地质、地球物理和地球化学的成果 ,对华北板内深部结构进行了研究。从深部构造角度划分出 6个金及多金属成矿带、4.金刚石成矿带 ,并对华北地区的地震及地热资源与新生带大陆裂谷的关系进行了探讨。

关键词：深部构造岩石圈-软流圈结构地震层析成象区域成矿作用华北板块构造应力场

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

喜马拉雅琼嘉岗伟晶岩型锂矿成矿地质特征和形成机制

引用

岩石学报 2024年第9期40卷 2664-2678页

作者：赵俊兴秦克章何畅通李俊瑜刘宇超施睿哲朱丽群赵永能林伟吴福元中国科学院矿产资源研究重点实验室中国科学院地质与地球物理研究所北京100029 岩石圈演化与环境演变全国重点实验室中国科学院地质与地球物理研究所北京100029 中国科学院大学地球与行星科学学院北京100049

西藏喜马拉雅琼嘉岗伟晶岩型锂矿是喜马拉雅稀有金属成矿带标志性的伟晶岩型矿床。其成矿地质特征、成矿机理-机制和含矿性评价的研究对喜马拉雅稀有金属成矿带的形成机制和找矿勘查工作研究具有重要意义。中国科学院地质与地球物理研... 详细信息

西藏喜马拉雅琼嘉岗伟晶岩型锂矿是喜马拉雅稀有金属成矿带标志性的伟晶岩型矿床。其成矿地质特征、成矿机理-机制和含矿性评价的研究对喜马拉雅稀有金属成矿带的形成机制和找矿勘查工作研究具有重要意义。中国科学院地质与地球物理研究所在2.2.~2.2.年期间对喜马拉雅琼嘉岗伟晶岩型锂矿形成机制研究中,获得如下认识:(1)琼嘉岗锂辉石伟晶岩的主矿体主要顺矽卡岩化大理岩和钙质千枚岩面理侵入,中部整体上呈板状近水平(10°~2.°),主矿体两侧倾角相对较大(30°~50°);(2.琼嘉岗矿床的富锂矿物主要为锂辉石(包括3个期次),次为透锂长石、锂绿泥石、锂云母等,其他稀有金属矿物包括绿柱石、日光榴石、羟硅铍石、铌锰矿-铌铁矿、锡石等,围岩蚀变主要为矽卡岩化并含有少量锡矿化;(3)琼嘉岗锂矿中花岗岩-伟晶岩的演化和成矿受岩浆结晶分异过程控制,锂辉石伟晶岩矿体的形成与系统大量流体出溶有关,花岗质熔体演化的早期阶段稀有金属可能达到饱和;(4.钾长石Ti温度计和流体包裹体等容线相交法揭示出从电气石白云母花岗岩到锂辉石伟晶岩呈现降温趋势,锂辉石伟晶岩石英形成时流体的捕获温度为4.0~4.5℃,捕获压力为180~2.0MPa,结合含锂矿物相关系揭示出降压是锂辉石伟晶岩形成的重要机制;(5)建立了琼嘉岗锂矿的成矿模式,指出高度结晶分异、流体出溶和降压过程控制了琼嘉岗锂辉石伟晶岩的形成,流体交代作用形成了稀有金属矿化;(6)长石结构和化学成分(Rb、Cs、Sr、Ba、K/Rb和形成温度)、石榴子石组成(高水含量、高Mn/(Mn+Fe)的锰铝榴石)、副矿物组成及其包裹矿物类型是琼嘉岗及周边伟晶岩含矿性评价的有效指标。

关键词：琼嘉岗锂矿地质特征成矿机制成矿模型喜马拉雅稀有金属成矿带

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

喜马拉雅东段库曲锂辉石伟晶岩铌钽矿物特征及指示意义

引用

地质学报 2024年第5期98卷 1473-1488页

作者：周起凤秦克章何畅通刘宇超施睿哲赵俊兴陈彤莫凌超中国冶金地质总局矿产资源研究院北京101300 中国科学院矿产资源研究重点实验室中国科学院地质与地球物理研究所北京100029 中国科学院大学地球与行星科学学院北京100049

铌钽矿物是花岗伟晶岩中重要的稀有金属矿物,记录了伟晶岩岩浆分异演化过程。喜马拉雅中段和东段新近取得伟晶岩型锂矿重要找矿发现。本文针对东段库曲岩体中三处含锂辉石伟晶岩脉和白云母花岗岩产出的铌钽矿物(铌铁矿族矿物和细晶石)... 详细信息

铌钽矿物是花岗伟晶岩中重要的稀有金属矿物,记录了伟晶岩岩浆分异演化过程。喜马拉雅中段和东段新近取得伟晶岩型锂矿重要找矿发现。本文针对东段库曲岩体中三处含锂辉石伟晶岩脉和白云母花岗岩产出的铌钽矿物(铌铁矿族矿物和细晶石)进行内部结构和化学组成研究。含锂辉石伟晶岩脉中的铌铁矿族矿物(CGM)为铌锰矿-钽锰矿,产出均一、核-边、补丁、不规则分带、振荡环带和复合结构,分为三个形成世代(CGM-I、CGM-Ⅱ、CGM-Ⅲ),由CGM-I至CGM-Ⅱ,铌铁矿族矿物向富Ta、Fe和略贫Y方向演化,体系经历了含Nb、Mn和Y矿物的结晶分异作用,形成了富Ta和Fe的富挥发分熔体或流体,由CGM-Ⅱ至CGM-Ⅲ,铌铁矿族矿物Ta/(Nb+Ta)和Mn/(Fe+Mn)值变化不一,反映了复杂的矿物-流体相互作用。含锂辉石伟晶岩脉和白云母花岗岩中的细晶石产出均一、核-边和不规则分带结构,分别揭示了富Ta和Ca流体作用、边界层效应或富Nb流体交代、以及动荡结晶环境下流体扰动。细晶石的TiO2.UO2.F含量以及Ta/(Nb+Ta)值可作为岩浆分异演化程度的潜在指示标志,但需考虑晚期热液流体对细晶石化学组成的影响。铌钽矿物研究揭示了库曲不同含锂辉石伟晶岩脉的岩浆特征与分异演化过程。1号含锂辉石伟晶岩脉岩浆相对富Fe,依次经历了含Fe矿物、含Nb和含Mn矿物、以及含Ta和含Mn矿物的结晶作用,局部伴随边界层效应或含Fe矿物结晶,晚期存在富Ta和Ca流体活动,并受边界层效应影响。2.含锂辉石伟晶岩脉岩浆就位后首先经历了含Nb和含Fe矿物结晶,之后经历了含Mn和含Y矿物结晶以及含Nb和含Ta矿物结晶耦合作用,晚期发育富Ta和Ca流体活动,随后发生富Nb流体作用。3号含锂辉石伟晶岩脉岩浆相对富挥发分,就位后经历了含Nb、Mn和Y矿物的结晶作用,以及复杂的矿物-液相介质相互作用,体系晚期存在富Ta和Ca流体活动。库曲含锂辉石伟晶岩脉经历了熔体、富稀有金属和挥发分熔体至复杂流体(富Ta和Ca流体和富Nb流体等)的演化过程。铌钽矿物的内部结构分带和化学组成特征揭示了库曲岩体中淡色花岗岩和伟晶岩脉经历的岩浆分异演化过程以及晚期复杂的流体活动。

关键词：铌铁矿族矿物细晶石岩浆分异演化库曲含锂辉石伟晶岩脉喜马拉雅

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

Effects of water discharge on river-dominated delta growth

引用

Petroleum Science 2021年第6期18卷 1630-1649页

作者： Yan-Bao Zhang Yi-Ke liu Jia Yi Xue-Jian liu institute of geophysics China Earthquake AdministrationBeijing100081China Key laboratory of Petroleum Resources Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China China Earthquake Disaster Prevention Center China Earthquake AdministrationBeijing100029China The Pennsylvania State University Department of GeosciencesUniversity ParkPA16802USA

River-dominated deltas are commonly developed at modern bays and lakes and ancient petroliferous *** discharge is an important variable at pay zone scales in river-dominated delta reservoirs,which affects deltaic sand distributions and ***,it's unclear how it influences riverdominated delta *** paper integrates Delft3 D simulations and modern analogs to analyze the effects of water discharge,considering growth time,sediment supply,and coupled effects of sediment *** water discharges lead to the formation of lobate deltas,and the water discharge of 1,000 m~3/s is a referenced threshold ***-grained,highly-cohesive sediments increase the threshold values of water discharge at which the deltas become lobate from digitate,and vice *** the same simulation time,high water discharges favor more rugose shorelines,more distributary channels(especially secondary distributaries),and longer and wider deltas with more land ***,for the same sediment supply,high water discharges have few effects on shoreline roughness and the number of distributary channels.

关键词： River-dominated delta Water discharge Morphology Distributary channel Hydrocarbon exploration

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

P wave velocity structure of upper and middle crust beneath the Three Gorges reservoir dam and adjacent regions

引用

Science China Earth Sciences 2009年第4期52卷 567-578页

作者： LI Qiang zhao Xu CAI JinAn liu RuiFeng LONG GuiHua AN YanRu National Earthquake Infrastructure Service China Earthquake AdministrationBeijing 100037China China Earthquake Network Center China Earthquake AdministrationBeijing 100045China institute of Earthquake Science China Earthquake AdministrationBeijing 100036China institute of geology and {2. Chinese Academy of SciencesBeijing 100029China

The three-dimensional P wave velocity structures of upper and middle crust beneath the Three Gorges reservoir dam and adjacent regions were reconstructed by means of the seismic tomography, using the absolute P-arrivals from the events observed by the Three Gorges seismic network. Our preliminary study of the deep structure shows: (1) the lithology of the Huangling anticline, integral and highly so-lidified, exhibits a uniformity. Down to a depth of 2. km, the Huangling anticline still shows high- velocity anomalies. Note that the characteristics of the velocity images with the different depths are not the same; (2. the depth of the sedimentary rocks beneath the entire Zigui basin is not constant, which is less than 6 km; (3) the top boundary of the crystalline basement varies from 0 to 7 km, whereas the bottom one between 14.and 16 km; (4. the partially molten substances of the upper mantle are located in the Badong-Zigui and its adjacent regions as well as nearby Peishi area. The development and evo-lution of the current tectonics are associated with the cooling and solidifying process of the molten substances within the upper mantle; (5) the different velocity structures of the deep crust in both east and west side of the Jiuwanxi fault are to be investigated in order to understand the origin of gravita-tional gradient zone in the Three Gorge areas; and (6) the velocities within the upper crust would be affected by reservoir water permeability.

关键词： Three Gorges reservoir upper and middle crust three-dimensional 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

Sapphirine-Bearing Pelitic Granulite from Ailaoshan Orogen,West Yunnan,China: Metamorphic Conditions and Tectonic Setting

引用

Journal of Earth Science 2019年第3期30卷 621-635页

作者： Cheng Wei Yuhao zhao Luhua Zhu Xuexiang Qi Zhihui Cai Xufeng liu Guangfei Ma Key laboratory for Continental Dynamics of Ministry of Land and Resources Institute of GeologyChinese Academy of Geological Sciences Beijing 100037 China School of Earth and Space Sciences Peking University Beijing 100871 China Nanjing institute of geology and Mineral Resources Chinese Academy of Geological Sciences Nanjing 210016 China geology Bureau for Nonferrous Metals of Guangdong Province Guangzhou 510080 China Hangzhou Mechanical Design Research institute of Ministry of Water Resources Standard & Quality Control Research Institute of Ministry of Water Resources Hangzhou 310012 China

To reveal the petrological characteristics, metamorphic evolution histon and tectonic setting of the pelitic granulites from Ailaoshan Orogen, Uest Yunnan, China, a comprehensive study in mineral chemistry, petrogeochemistry and geochronology studies is presented in this paper. Two metamorphic stages of the granulites can be established:(1) the peak metamorphism recorded by the mineral assemblage of garnet, kyanite, K-feidspar and rutile, and the initial retrograde metamorphism shown by the mineral assemblage of garnet, sillimanite, sapphirine, spinel, K-feldspar, plagioclase and biotite;(2. the superim-posed metamorphism recorded by the mineral assemblage of biotite, muscovite, plagioclase, quartz and ilmenite. Zircon LA-ICP-MS U-Pb dating indicates that the protolith of the granulite was deposited after 337 Ma. The initial retrograde metamorphism occurred at P-T conditions of 8.6-12.kbar at 850-92.℃ estimated by mineral assemblages, the low pressure limit of kyanite stability and GBPQ geothermobarometer in Indosinian (about 2.5 Ma), and the late superimposed metamorphism occurred at the P-T condition of 3.5-3.9 kbar at 572.576℃ estimated by GBPQ geothermobarometer since 33Ma. The first stage was related to the amalgamation of the South China and Indochina blocks during the Triassic, and the second stage was possibly related with the large scale sinistral slip-shearing since the Oligocene. It is inferred that the upper continental crust was suhducted/underthrusted to the lower continental crust (deeper than 30 km) and underwent granulite-facies metamorphism and then quickly exhumed to the middle-upper crust (10-12.km) and initial retrograde metamorphism occurred due to the collision of the Indochina and South China blocks during Indosinian, which was followed by superimposition of the second stage of metamorphism since the Oligocene.

关键词： high-pressure pelitic granulite sapphirine zircon LA-ICP-MS U-Pb dating metamorphic rocks Ailaoshan Orogen

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

Comment on"Mudflat/distal fan and shallow lake sedimentation (upper Vallesian-Turolian) in the Tianshui Basin,Central China:Evidence against the late Miocene eolian loess"by ***-Zarza,***,***,***,***,***-Perez,***-Garcia,X.X

Comment on"Mudflat/distal fan and shallow lake sedimentation...

引用

中国科学院地质与地球物理研究所第十届(2.10年度)学术年会

作者： Z.T.Guo~(a,*),J.Y Ge~a,G.Q,Xiao~(b,c),Q.Z.Hao~a,H.B.Wu~a,T.Zhan~a,L liu~a,L Qin~a,F.M.Zeng~a,B.Y.Yuan~a a institute of geology and geophysics,Chinese Academy of Sciences,P.O.Box 982.,{2. {4.,China b institute of Earth Environment,Chinese Academy of Sciences,Xian 710075,China c Graduate School of the Chinese Academy of Science,{2. 100039,China

Alonso-Zarza et al.(2.09)argued that the Miocene sedimentary sequence near Qinan(QA-I)(Guo et al., 2.02.,north to Tianshui in Central China,represents mudflat/distal fan and shallow lake *** we show that they(1)did not take into account extensive observational evidence supporting an eolian origin;(2.erroneously correlated deposits of different origins and small lateral extent occurring in different geomorphic units;(3)inferred a common origin for distal fans in the Tianshui and Qinan regions despite contrasting tectonic and geomorphic conditions;and(4.in some cases misinterpreted features typical of eolian ***,their study is not a sufficient basis for challenging earlier interpretations of Asian paleoclimates.

关键词： Miocene and Pliocene eolian deposits Fan and distal fan sediments Asian drying

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Recent Progresses on Ionospheric Climatology Investigations

引用

空间科学学报 2012年第5期32卷 665-680页

作者： liu Libo WAN Weixing CHEN Yiding LE Huijun zhao Biqiang (beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029

The ionosphere varies over multiple time scales,which are classified into two categories: the climatology and weather *** this national report,we give a brief summary of recent progresses in ionospheric climatology with focus on(1) the seasonal variations,(2. solar cycle effects, and(3) empirical modeling of the *** seasonal variations of the ionosphere have been explored in many works to give a more detailed picture with regional and global features at various altitudes by analyzing the observation data from various sources and ***,a series of studies reported the response of the ionosphere to solar cycle variations,which revealed some novel and detailed features of solar activity dependence of ionospheric parameters at different altitudes. These investigations have improved our understanding on the states of the ionosphere and underlying fundamental processes,provided clues to future studies on ionospheric weather,and guided ionospheric modeling,forecasting and related applications.

关键词： Ionosphere Climatological variation Seasonal variations Solar cycle Ionospheric modeling

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：