检索结果-南通市图书馆

TWO TYPES OF XENOLITH—MANTLE XENOLITH AND CRUSTAL XENOLITH FOUND IN THE CENOZOIC VOLCANIC ROCKS FROM HOH XIL, NORTHERN TIBET PLATEAU

引用

地学前缘 2000年第S1期7卷 197-198页

作者： Wu Cailai,Yang Jingsui,Li Haibing,Shi Rendeng[WT5,5”BX](institute of {1.,chinese {3. of geological sciences,beijing 1.003.,China)

It is known that large amounts of Cenozoic high potassium volcanic rocks occur on the Tibetan plateau. The question is where do those high potassium magmas come from? Since the plateau is being compressed by subduction and collision from the surrounding continents,it is a puzzle for us what is the formational environment and tectonic setting of these volcanic rocks? In particular,what is the relationship between these special rocks and formation and uplift of the plateau? We recently carried out an investigation on these Cenozoic volcanic rocks in Hoh Xil,northern Tibetan plateau,including volcanic rocks in the Jingyuhu,Xiongyingtai and Shuangquanzi areas. In the region,some older lava flows occur as thick sheets with a flat surface and weathering crust; while some relatively younger lavas remain a relict volcanic cone or vent. Most of the relict cones are small (1.0m in diameter) and some are over hundred meters,distributed along faults,particular strike\|slip fault,e.g.,East Kunlun strike slip fault. Relatively,intermediate\|acid volcanic rocks are prominent,and basic\|intermediate and acid are subordinate. Petrological and geochemical results show that these volcanic rocks have many common affinities,characterized by high contents of w (K 2O)+ w (Na 2O) (about 8%),and w (K\-2O)/ w (Na\-2O)>1.or close to 1.and mostly belonged to shoshonite\|trachyte association and some to ultra\|potassic rocks. The K\|Ar dating of whole rock and mica shows that the volcanism lasts from middle Miocene (1. 47Ma) to Pleistocene (0 69Ma); they are 0 69Ma,1.0}77Ma and 1. 47Ma in Jingyuhu; 1. 05Ma,1. 22Ma and 1. 83.a in Xiongyingai,; 1.58Ma,2 24Ma,5 23.a,5 85Ma,8 20Ma,8 41.a and 1. 67Ma in *** types of xenolith and xenocryst were found in Jingyuhu and Xiongyingtai,i.e..,crustal xenolith and mantle xenocryst.

关键词： xenolith xenocryst shoshonite trachyte Cenozoic volcanic r ock Tibet Hoh Xil

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

A new species of Leptocycas (Zamiaceae) from the Upper Triassic sediments of Liaoning Province,China

引用

Journal of Systematics and Evolution 2010年第4期48卷 286-301页

作者： 1,2,3.ian-Wei ZHANG 2Jian-Xin YAO 1Jia-Rui CHEN 1Cheng-Sen LI 1(State Key Laboratory of Systematic and Evolutionary Botany,institute of Botany,{1. academy of {3.,beijing 100093.China) 2(State Key Laboratory of Stratigraphy and Paleontology,institute of geology,{1. academy of geological {3.,beijing {1.},China) 3.Graduate University,{1. academy of {3.,beijing 100049,China) (State Key Laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (State Key Laboratory of Stratigraphy and Paleontology Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China) (Graduate University Chinese Academy of Sciences Beijing 100049 China) *Correspondence: Cheng-Sen LI *Correspondence: ?Author for correspondence. E-mail: lics@*** Tel.: 86-1.-6283.643. Fax: 86-1.-6259-3.85.

A new cycad,Leptocycas yangcaogouensis ***.,was found in sediments from the Late Triassic in western Liaoning,*** pinnately compound leaves(Pseudoctenis type)are screwed in a crown on the stem *** leaflets are linear,with parallel veins and decurrent bases on the *** leaf bases are *** cataphylls intermix with the *** female cone is ovoid in *** characteristics of the new plant are more similar to those of Leptocycas gracilis,a Triassic cycad from North America,but the new species differs from *** in the size of its stem(7–8 vs.3.5 cm in diameter,respectively),leaves(length×width 1.0×1. vs.3.×7 cm,respectively)and leaf density along the stem(4–6 vs.1.2 bases/1.cm length,respectively).Both *** and ***,having leaves of the Pseudoctenis type,show a closer relationship to the extant Dioon of *** present study provides evidence for the origin of the genus Dioon,which may have come from Leptocycas plants of the *** would be assumed that the extent cycads in Zamiaceae originate from the pteridosperms in the Late Paleozoic and have evolved through the stage of *** and *** in Late Triassic,and reaching the extant Dioon.

关键词： China Cycadales Leptocycas Upper Triassic Zamiaceae

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

Geochronology of middle Neoproterozoic volcanic deposits in Yangtze Craton interior of South China and its implications to tectonic settings

引用

Science China Earth sciences 2010年第9期53卷 1307-1315页

作者： WANG ZhengJiang1. WANG Jian1. DUAN TaiZhong2, XIE Yuan1. ZHUO JieWen1.3.& YANG Ping1.1.Chengdu{1. and Mineral Resources, Ministry of Land and Resources, Chengdu 61.082, China 2 Marathon Oil UK Ltd., Aberdeen, Scotland, AB1. 6FZ, UK 3.Graduate Department,{1., beijing 1.003., China 1. Chengdu institute of geology and Mineral Resources Ministry of Land and Resources Chengdu 610082 China2. Marathon Oil UK Ltd. Aberdeen Scotland AB15 6FZ UK3. Graduate Department Chinese Academy of Geological Sciences Beijing 100037 China

Here we report new shrimp dating results of the crystal tuff in Ejiaao Formation of middle Banxi Group in northern Guizhou. The results indicate that the volcanic deposition occurred at ~780 Ma. We also suggests that the igneous activities across Yangtze Craton with diabase dyke swarms and basal volcanic rocks during middle Banxi time are indicative of the episodic, extensive and vigorous great bimodal igneous events during middle Neoproterozoic (825-720 Ma) in South China. The characteristics of the igneous series are contrary to the model claiming they are of island-arc origin, but suggest that they are the records of rifting process and may be related to the episodic plume activities leading to the break-up of Rodinia.

关键词： Yangtze Craton middle Neoproterozoic Ejiaao Formation of Banxi Group shrimp zircon U-Pb dating episodic and bimodal igneous series

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

Serpentinization of peridotites from the southern Mariana forearc

引用

Progress in Natural Science:Materials International 2009年第10期19卷 1287-1295页

作者： Xiaomei Wang a,b,Zhigang Zenga,Junbing Chenc a Key Laboratory of Marine geology and Environment,{1. of Oceanology,chinese {3. of sciences,7 Nanhai Road,Qingdao 266071.China b Graduate School of chinese {3. of sciences,1. Yuquan Road,beijing 1.0049,China c geological Brigade of Hydrogeology and Engineering geology,Zhejiang geological Prospecting Bureau,206 Baoshan Road,Ningbo 3.501.,China [a]Key Laboratory of Marine geology and Environment Institute of Oceanology Chinese Academy of Sciences 7 Nanhai Road Qingdao 266071 China [b]Graduate School of chinese {1. of sciences 19 Yuquan Road Beijing 100049 China [c]geological Brigade of Hydro{1. and Engineering {1. Zhejiang Geological Prospecting Bureau 206 Baoshan Road Ningbo 315012 China

A detailed petrologic and mineralogic study was carried out on serpentinized peridotites dredged from the southern landward slopes of the Mariana Trench,in order to reveal the serpentinization process of these unusual rocks and to identify the sole presence of the mineral *** constituent minerals of these southern Mariana forearc peridotites are olivine,amphibole and spinel,as well as serpentine,chlorite and *** with serpentinite seamounts,the serpentinized peridotites from the southern Mariana forearc are characterized by the absence of magnetite and brucite,and the common presence of talc;besides,the serpentine mineral variety is simplex,only *** mineral chemistry and mineral phase relationships,we conclude that(1. the absence of magnetite in the serpentinized peridotites is due to incomplete serpentinization,other than magnetite,the iron end-member in olivine forms Ferich brucite and Fe-rich serpentine;(2) brucite is not stable with high silica activity,reacting with later SiO2-rich fluid and then forming lizardite,leading to a lack of brucite in these serpentinized peridotites;(3. the occurrence of talc is the result of later SiO2-rich fluid reactions with lizardite;and(4) the reason for the sole occurrence of lizardite is that the temperature condition of our study are awas nothig henough for the formation of antigorite(whichisstable at >500 °C).Despite the broad overlap of lizardite and chrysotile in growth temperature,differences in the modes of occurrence of lizardite and chrysotile,such as the scarcity of H2O,low porosity and permeability,as well as the actual situation of initial serpentinization in the study area,result in the absolute prevalence of lizardite over chrysotile in the area.

关键词： Peridotite Serpentinization Mineral chemistry Lizardite Mariana

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

Conceptual design,data model and key techniques of“3. Assistant”

引用

中国有色金属学会会刊：英文版 2011年第S3期21卷 692-698页

作者： LI Qing-yuan1. ZHANG Xuan2, JIN Yang2, ZHOU Hui3. WANG Qian-jin3.WEI Zhan-yin1.1. Key Laboratory of Geo-Informatics, chinese {1. of Surveying and Mapping, beijing 1.083., China 2. School of Geo-Science and Surveying Engineering, China University of Mining and Technology, beijing 1.0083. China 3. School of Geomatics, Liaoning Technical University, Fuxin 1.3.00, China [a] Key Laboratory of Geo-Informatics Chinese Academy of Surveying and Mapping Beijing 100830 China [b] School of Geo-Science and Surveying Engineering China University of Mining and Technology Beijing 100083 China [c] School of Geomatics Liaoning Technical University Fuxin 123000 China

Conceptual design, data model and key techniques of "Geo-engineer 3. assistant", an underground 3. GIS oriented to geology and mine application, were discussed. In particular, the importance of high-order smoothing triangular pieces to surface's fine expression in {1. modeling was emphasized. The contour mode is the most favorite mode of the three modes about surface expression: DEM, TIN and contour. Topology in underground 3. modeling with CAGD was compared. From the view of boundary and coboundary, which is soul of IS 1.1.7 (Geographic information spatial schema), 3. underground topology was re-examined.

关键词： 3. assistant true 3. GIS fine expression of surface contour mode 3. topology

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

NORTH QAIDAM ULTRAHIGH PRESSURE METAMORPHIC (UHPM) BELT ON THE NORTHEASTERN QINGHAI-TIBET PLATEAU AND ITS EASTWARD EXTENSION

引用

地学前缘 2000年第S1期7卷 241-242页

作者： Yang Jingsui 1. Song Suguang 1. Wu Cailai 1. Shi Rendeng 1. Marc Jalivet 2(1.0},{1., beijing 1.003., China 2 Department of {3., University of Montpellier II, Montpellier, France)

Eclogite was firstly discovered at the Da Qaidam region (Yang,et al., 1.98), and then in the Xitieshan and Dulan regions in 1.99, constituting an over 3.0km long high\|pressure metamorphic belt in the northeastern Qinghai—Tibet plateau. Eclogites occur as pods in the garnet\|muscovite gneiss of the Dakendaban Group (or called Shaliuhe Group in Dulan) of Upper Proterozoic age. In general, the pods of eclogite vary in size; most of them are less than 20m×1.m, some large ones up to about 1.0m×50m. The eclogite\|hosted gneiss is pale\|gray in color, consisting mainly plagioclase and quartz, and minor muscovite (5%～1.% in vol.) and garnet (1.～2%). Some of the country rocks of eclogite are mica\|quartz\|(feldspar) schist, quartzite, and ultramafic rocks, the latter also occur in *** 50 pods were found in a belt of 1.km×3.m in the Da Qaidam region (No.1.location). Only a few pods of eclogite were found in the Xitieshan region in 1.99 field expedition (No.2 location). Eclogite in Dulan occurs in the Proterozoic strata of Shaliuhe Group (same as the Dakendaban Group but with a different name). The eclogites in the Dulan region (No.3.location) expose about 1.km wide in SN and an unknown length in EW, and can be subdivided into two belts, the North Eclogite Belt of Dulan (NEBD) and the South Eclogite Belt of Dulan (SEBD).

关键词： eclogite UHP ultrahigh pressure metamorphism coesite dulan Da Qaidam Qinghai Tibet

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

shrimp dating of the Bangong Lake SSZ-type ophiolite: Constraints on the closure time of ocean in the Bangong Lake-Nujiang River,northwestern Tibet

引用

chinese Science Bulletin 2007年第7期52卷 936-941页

作者： SHI RenDeng1.2 1.School of Earth and Space sciences, University of Science and Technology of China, Hefei 2{1.026, China 2{1., chinese academy of geological sciences,{{1., China (email: shird@***) School of Earth and Space sciences University of Science and Technology ofChina Hefei 230026 China

The Bangong Lake ophiolite is located in the westernmost part of the Bangong Lake-Nujiang River suture zone. It is a tectonic mélange consisting of numerous individual blocks of peridotite, pillowed and massive lavas and mafic dykes with SSZ-type ophiolitic geochemical affinity formed at the end of a Wilson circle. The shrimp U-Pb ages of the co-magmatic zircon domains from one gabbroic dyke (Sample 01.-1.5) range from 1.2.5±8.6 Ma to 1.7.1.1.4 Ma with an average of 1.7.0±1.4 Ma (n = 1., MSWD = 1.2), suggesting that the subduction of the Bangong Lake Neo-Tethyan Ocean started before the Middle Jurassic. It is inferred that the tectonic transform from spreading to subduction of the Neo-Tethyan Ocean began before the Middle Jurassic in the Bangong Lake area.

关键词：西藏班公湖怒江缝合带古海洋闭合时期 SSZ型蛇绿岩 shrimp 测年

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

Zircon shrimp U-Pb dating for gabbro at Chaotiehe in the Haicheng area, eastern Liaoning

引用

Science Bulletin 2010年第Z1期 403-410页

作者： MIAO LaiCheng1. ZHANG FuQin1. LIU DunYi2, SHI YuRuo2 & XIE HangQiang21.0} and Geophysics, {1. academy of {3., beijing 1.0029, China 2 beijing shrimp Centre, institute of geology, chinese academy of geological sciences, beijing 1.003., China

Chaotiehe gabbroic intrusion in the eastern part of Liaoning Province was dated by the zircon shrimp U-Pb technique. The results gave an emplacement age of 1.6±4 Ma, indicating that the intrusion thus formed during the lithospheric thinning of the North China Craton (NCC) in the Early Cretaceous rather than in a rifting setting during the Paleoproterozoic as previously thought. The gabbroic intrusion contains abundant old zircons with Paleoproterozoic (2.1.-2.46 Ga and ca. 1.87 Ga) and Neoproterozoic (747-969 Ma) ages. The Paleoproterozoic zircons were probably derived from NCC itself, whereas the Neoproterozoic ones were likely from materials of the Yangtze Craton that had previously been subducted beneath NCC. These geochronological dates are of important implications for understanding the Mesozoic crustal evolution of NCC.

关键词： Gabbro zircon shrimp age eastern Liaoning Province North China 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

Types, Metallogenic Environments and Characteristics of Temporal and Spatial Distribution of Copper Deposits in China

引用

Acta Geologica Sinica(English Edition) 1989年第1期63卷 79-92页

作者： Wang Zhitian and Qin Kezhang beijing{1. for Mineral Resources, CNNC, beijing Zhang Zhongmin CNNC BEIJING INST GEOL MINERAL RESOURCESBEIJINGPEOPLES R CHINA

Based upon a comprehensive study of 1.3.copper deposits in China. this paper reaches the following conclusions: 1. The crust in China was solidified pretty late; with the accretion of the plate, the copper mineralization moved towards its margin in space and became successively younger in age. 2. The major copper ore types ever found in the world have mostly been discovered in China, in which the porphyry type seems to be the most important and the massive sulfide type in the transitional bed between marine clastic and carbonate rocks is clearly defined. 3. Carbonate strata are widespread in China and their deposition lasted for a long geological period, so the proportion of copper deposits occurring in them is large as compared with other parts of the world. 4. Seven metallogenic epochs can be recognized, in which the Mesozoic one plays the leading role and the middle(late) Palaeozoic and Cenozoic ones are next in importance. Mineralization was comparatively simple in the early geological period. and became diversified later on. In the early epochs copper deposits related to basaltic magmatism and metamorphosed marine sediments predominated, whereas in the later epochs those related to granitic magmatism and continental sedimentation were dominant. 5. There exist in China thirteen metallogenic provinces, of which the Lower Yangtze downwarping belt, Sanjiang fold system, Jiangnan axis and Xikang-Yunnan axis are of greater significance. 6. The crustal mobility in China was rather pronounced, the polycyclic evolution of the crust has resulted in such obvious phenomena as the inheritance of mineralization, the coexistence of various types and the superposition of different genetic types.

关键词： Metallogenic Environments and Characteristics of Temporal and Spatial Distribution of Copper Deposits in China Types

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

Deep Tectonophysical Process of the Uplift of the Northern Qinghai--Tibet Plateau--Evidence from the Integrated geological--Geophysical Profile from Golmud to the Tanggula Mountains, Qinghai Province, China

引用

Acta Geologica Sinica(English Edition) 1997年第1期71卷 1-14页

作者： Xu Zhiqin Jiang Mei and Yang Jingsui chinese academy of geological sciences, {1. Jiang Minxi chinese {1. of geological {3. Beijing [?]Xu Zhiqin Born in 1.41.and graduated from the Department of geology Peking University in 1964. She has been doing research work mainly on structural geology etc. in the Institute of Geology Chinese Academy of Geological Sciences and now is Research Professor of the Institute of Geology CAGS and member of the Chinese Academy of Sciences.

The tectonic activities occurring since the Cenozoic in the northern part of theQinghai-Tibet Plateau (the region from the East Kunlun Mountains to the Tanggula Mountains)were probably caused by the intense intraplate deformation propagation after the collision be-tween the Indian plate and the Eurasian plate. Their main expressions include the substantial up-lifting of the plateau, alternation of horizontal extension and compression under the verticalgreatest principal stress σ_1. occurrence of rift-type volcanic activity, formation of thebasin-range system, and successive eastward extrusion of blocks resulting from large-scalestrike-slip faulting. Geophysical exploration and experiments have revealed that there exist close-ly alternating horizontal high-velocity and low-velocity layers as well as lithospheric faults of aleft-lateral strike-slip sense in the lower part of the lithosphere (the lower crust and lithosphericmantle, 60-1.0 km deep). Based on an integrated study of the geological-geophysical data avail-able, the authors have proposed a model of deep-seated mantle diapir and the associatedtectonophysical process as the dynamic source for the uplift of the northern part of theQinghai-Tibet Plateau.

关键词： northern Qinghai-Tibet Plateau geophysics uplift mantle diapir

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：