检索结果-南通市图书馆

Petrogenesis of Songshugou dunite body in the Qinling orogenic belt, Central china: Constraints from geochemistry and melt inclusions

引用

Science china Earth Sciences 2005年第8期48卷 1146-1157页

作者： SU Li1,2. SONG Shuguang3 & ZHOU Dingwu1 1. Key laboratory of Continental Dynamics of the Ministry of Education, Department of Geology, Northwestern university, Xi’an 710069, {2. 2. the geological lab center, {2. university of geosciences (beijing), beijing 100083. china 3. Key laboratory of Orogenic Belts of the Ministry of Education, Department of Geology, Peking university, beijing 100871, {2. Key laboratory of Continental Dynamics of the Ministry of Education Department of Geology Northwestern University Xi’an China The geological lab {2. China University of Geosciences (Beijing)Beijing China Key laboratory of Orogenic Belts of the Ministry of Education Department of Geology Peking University Beijing China

The Songshugou dunite body, which occupies an area of about 2. km2. is the largest ultramafic massif in the eastern Qinling orogenic belt, Central china. The major compo-nent of this body is dunitic rocks including mylonitic dunite and coarse-grained dunite; they oc-cupy about 95 vol% of the total body. Petrography, mineral composition, major and trace ele-ments and primitive melt inclusions have been investigated in this paper; all revealed that this dunite body is the product of melt-rock interaction by porous percolation flow. In comparison with dunite sills or veins in harzburgite from the basal part of Oman ophiolite, this dunite body is characterized by lower contents of Al2.3, CaO and HREE but higher content of highly incom-patible elements and Zr and Hf. The LREE enriched patterns and primitive mantle normalized spidergrams of trace elements are also different from the Oman dunite. Combining with melt in-clusions observed in olivines, we conclude that this dunite body is the product of large- scale porous percolation flow of high-MgO melts within depleted mantle peridotites. The high-MgO magma, in essence, was most probably produced at the hot head of an upwelling mantle plume. The occurrence of the Songshugou dunite body is closely associated with the activity of mantle super-plume in Neo-Proterozoic era in the Yangtze Craton.

关键词： Songshugou dunite body, geochemistry, melt inclusion, mantle plume, Qinling orogenic belt.

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

Petrogenesis and dating of the Kangding complex,Sichuan Province

引用

Science china Earth Sciences 2005年第5期48卷 622-634页

作者： CHEN Yuelong 1 , LUO Zhaohua 1 , ZHAO Junxiang, LI Zhihong, ZHANG Hongfei & SONG Biao 3 1. Faculty of Earth Sciences and Natural Resources, china university of {2., beijing 100083. china 2. Faculty of Earth Sciences, china university of {2., Wuhan 430074, china 3. beijing SHRIMP center, Institute of Geology, Chinese Academy of geological Sciences, beijing 100037, china Faculty of Earth Sciences and Natural Resources China University of Geosciences Beijing China Faculty of Earth Sciences China University of Geosciences Wuhan China beijing SHRIMP center Institute of Geology Chinese Academy of Geological Sciences Beijing China

An analysis of major and trace element geochemistry and SHRIMP U-Pb zircon dating of mafic, intermediate, and felsic rocks from the Mianning metamorphic complex of Si- chuan Province was conducted. One of our conclusions is that a majority of the zircons crystal- lized between 72. and 773 Ma in a magmatic regime. The complexes contain early to late Pa- leo-proterozoic relict zircons from ancient continental crust. The oldest age, 2.68 Ma, may rep- resent the basement of the Yangtze block. Overgrowth zircon rims and palingenetic zircons have been observed and dated, and are believed to have formed after crystallization, during Paleozoic and Mesozoic metamorphic-anatexis. We also conclude that depletion of Nb, Ta, HREE, in a spider-diagram normalized to primitive mantle and calc-alkaline association, implies that they formed in island-arc or under-plating settings.

关键词： Kangding complex, zircons, SHRIMP, tectonic setting.

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, {2. 2. Development and Research center, {2. geological Survey, beijing 100037, {2. 3. {2. university of geosciences, beijing 100083. china 4. {2. university of geosciences, Wuhan 430074, {2. 5. Information center of Ministry of Land and Resources, beijing 100812. {2. 6. Institute of Geology, State Seismological Bureau, beijing 10002., {2. Institute of Geology Chinese Academy of Geological Sciences Beijing China Development and Research center China Geological Survey Beijing China china university of {2. Beijing China china university of {2. Wuhan China Information center of Ministry of Land and Resources Beijing China Institute of Geology State Seismological Bureau 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

Origin,evolution and extinction of Cathaysia flora

引用

Chinese Science Bulletin 1999年第2期44卷 100-108页

作者： SUN Keqinchina university of {2., beijing 100083. china china university of {2. Beijing China

Recent research results showed that the Cathaysia flora originated and developed from the global uniform Lepidodendropsis flora of the Early Carboniferous, which had already become an independent flora in the early Late Carboniferous (Namurian B to C). The center of origin of the Cathaysia flora is restricted to the North china Plate. On the basis of the successional characteristics of the Cathaysia flora in different {2. ages, it may be divided into seven evolutionary stages. The evolutionary trend of the Cathaysia flora, as a whole, was characterized by the gradual increase of the typical Cathaysian elements in the sequence from the early Late Carboniferous to the early Late Permian, which began to decline during the late Late Permian. The climatic differentiation, tectonic movement,oceanic circulation, palaeogeographical environment, extraterrestrial event and plant evolution caused the mass extinction of the Cathaysia flora on a large scale by the end of the Permian.

关键词： Asia Cathaysia flora origin evolution extinction Late Carboniferous Permian.

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

Southeastern extension of the Red River fault zone (RRFZ) and its tectonic evolution significance in western South china Sea

引用

Science china Earth Sciences 2006年第8期49卷 839-850页

作者： LIU Baoming1,2.3, XIA Bin1, LI Xuxuan1,3, ZHANG Minqiang1,3, NIU Binhua2. ZHONG Lifeng1, JIN Qinghuan1,4 & JI Shaocheng1,5 1. Key laboratory of Marginal Sea Geology and Resources, Chinese Academy of Sciences,Guangzhou 510640, china 2. china university of geosciences (beijing), beijing 100083. china 3. Research center of Science & Technology Department, CNOOC, beijing 10002., china 4. Guangzhou Marine geological Survey, Ministry of Land & Resources, Guangzhou 510075, china 5. Ecole Polytechnique Montreal, H3C3A7, Canada Key laboratory of Marginal Sea Geology and Resources Chinese Academy of Sciences Guangzhou China china university of {2. (beijing) Beijing China Research center of Science & Technology Department CNOOC Beijing China Guangzhou Marine geological Survey Ministry of Land & Resources Guangzhou China Ecole Polytechnique Montreal Canada

Recent geophysical surveys and basin modeling suggest that the No.1 fault in the Ying- gehai basin (YGHB) is the seaward elongation of the Red River fault zone (RRFZ) in the South china Sea (SCS). The RRFZ, which separates the South china and Indochina block, extends first along the Yuedong fault, offshore of Vietnam, and then continues southward and breaks off into two branches: the Lupar fault and the Tinjia fault. The southern extension of the Lupar fault dies out beneath the NW Borneo while the Tinjia fault extends southeast and reaches the Brunei-Sabah area. According to the gravity and geomagnetic data, and the tectonic evolution of the basins, there are different evolution histories between the Wan’an basin (WAB) and the basins in the Nansha block. The Tinjia fault may be the boundary between the Balingian block and the Nansha block. Hence, the line linking the Yue- dong fault and the Tinjia fault, which both are continental margin faults and strike-slip ones in the geological evolution histories, constitute the boundary between the Indochina and Nansha block. The Lupar fault, in contrast, is an intraplate fault within the Indochina block. The results provide new hints for reconstructing the tectonic evolution history of the RRFZ and the opening of the SCS, and also a framework for hydrocarbon prospecting in the region.

关键词： Red River fault zone, tectonic evolution, fault, extension, western South china Sea.

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 U-Pb dating and Hf isotopic analyses of Middle Ordovician meta-cumulate gabbro in central Qiangtang, northern Tibetan Plateau

引用

Science china Earth Sciences 2010年第5期53卷 657-664页

作者： ZHAI QingGuo1 WANG Jun1, LI Cai2.& SU Li3 1 Institute of Geology, Chinese Academy of geological Sciences, beijing 100037, {2. 2.College of Earth Sciences, Jilin university, Changchun 130061, {2. 3 The geological laboratory center and State Key laboratory of geological Processes and Mineral Resources, {2. university of Geo- sciences,{12. Institute of Geology Chinese Academy of Geological Sciences Beijing China College of Earth Sciences Jilin University Changchun China The geological laboratory {2. and State Key laboratory of geological Processes and Mineral Resources China University of Geosciences Beijing China

Metabasites consisting of metamorphic ultra-mafic rocks, cumulate gabbro, gabbro (diabase), basalt, and plagiogranite are exposed at the Taoxinghu area in central Qiangtang, northern Tibetan Plateau. Zircon SHRIMP U-Pb dating for the cumulate gabbro yields a weighted mean age of 467±4 Ma, which is the oldest and most reliable magmatic age in this area. Zircon 176Hf/177Hf ratios range from 0.2.2.15 to 0.2.2.57, with εHf(t) values of 5.02.0.2., indicating that the cumulate gabbro was mainly derived from the depleted mantle. In addition, geochemical data of metabasites suggest that they have similar characteristics to those in the mid-ocean ridge basalts (MORB). The Taoxinghu metabasites may represent the fragment of Early Paleozoic ophiolite in the "Central Uplift" of the Qiangtang, northern Tibetan Plateau.

关键词： Qiangtang cumulate gabbro SHRIMP dating Hf isotope

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

Experimental study on interaction between simulated sandstone and acidic fluid

引用

Petroleum Science 2009年第1期6卷 8-16页

作者： Zhang Yongwang Zeng Jianhui Yu Bingsong State Key laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China Basin and Reservoir Research center China University of Petroleum Beijing 102249 China State Key laboratory of geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China

In order to investigate the controlling mechanism of temperature, fluid and other factors on water-rock interaction in the diagenetic process, we performed a series of simulated experiments on the interaction between two kinds of fluids with different salinity and a composite mineral system （simulated sandstone）, which contains albite, K-feldspar and other minerals. The experimental results showed that acidity was the most important factor that affected the dissolution of minerals in the composite mineral system. The lower the pH value, the more easily the minerals dissolved. At the same pH value, the dissolution abilities of different acids for various mineral components were also different. Compared to hydrochloric acid （inorganic acid）, oxalic acid （organic acid） was more able to dissolve aluminosilicate minerals. However, the dissolution ability of oxalic acid for carbonate minerals was lower than that of hydrochloric acid. In the process of fluid-rock interaction, dissolution of feldspar was relatively complicated. Increase of temperature would accelerate the dissolution of feldspar. Under acidic conditions, albite had a higher dissolution rate than K-feldspar. K-feldspar could dissolve and convert into montmorillonite and kaolinite, while albite could dissolve and convert into kaolinite both at 40℃ and 80℃. Presence of organic acid, and decrease of pH value and water salinity were all favorable for the dissolution of feldspar, but weakened the ability to form clay minerals.

关键词： Fluid simulated sandstone dissolution static experiment

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

Age of Yingfeng rapakivi granite pluton on the north flank of Qaidam and its geological significance

引用

Science china Earth Sciences 2004年第4期47卷 357-365页

作者： XIAO Qinghui1,2. LU Xinxiang1,3, WANG Fei4, SUN Yangui5, WEI Xiangdong3 & XING Zuoyun6 1. Division of Granite Geology, china geological Survey, Yichang 443003, china 2. Information center of Ministry of Land and Resources, beijing 100812. china 3. geological Survey of Henan Province and Institute of geological Research of Henan Province, Zhengzhou 450053, china 4. geological Institute, china Seismological Bureau, beijing 10002., china 5. geological Survey Institute of Qinghai Province, Xining 810032. china 6. china university of geosciences, Wuhan 430074, china Division of Granite Geology China Geological Survey Yichang China Information center of Ministry of Land and Resources Beijing China geological Survey of Henan Province and Institute of geological Research of Henan Province Zhengzhou China geological Institute China Seismological Bureau Beijing China geological Survey Institute of Qinghai Province Xining China china university of {2. Wuhan China

The Yingfeng rapakivi granite on the north flank of Qaidam is a newly discovered Proterozoic rapakivi pluton in china, which was found after the discovery of Shachang rapakivi in Miyun County, beijing and Kuandian rapakivi in Jilin Province. Yingfeng rapakivi pluton is ex-posed on the north side of the suture belt between Qinling-Kunlun orogenic belt and North china plate. U-Pb zircon isotopic dating and Ar-Ar isotopic dating of both hornblende and K-feldspar from the Yingfeng rapakivi granite have been conducted. The results show that the age of (1776±33)Ma at the upper intercept in Concorde diagram represents the age of formation of the plu-ton, whereas the age of (52. 2.1) Ma at the lower intercept and Ar-Ar mineral dating of horn-blende and K-feldspar correspond to the age of a later event affecting the pluton, suggesting that Yingfeng pluton has ever been affected by strong regional Caledonian-Hercynian tectonic movement after its formation. The discovery of middle Proterozoic Yingfeng rapakivi granite pro-vides a petrologic evidence for the timing of cratonization of both the continental crust basement in western china and the basement of the North china plate and for a rifting event taking place in the mid-Proterozoic, suggesting that an amalgamation of ancient china continents had ever happened during the L liang Movement?between the early Proterozoic and the mid-Proterozoic.

关键词： rapakivi, U-Pb dating, Ar-Ar dating, Kunlun-Qinling orogenic belt.

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

An eSnake model for medical image segmentation

引用

Progress in Natural Science:Materials International 2005年第5期15卷 424-429页

作者： Lv Hongyu1, YUAN Kehong2. BAO Shanglian1, ZU Donglin1 and DUAN Chaijie1*(1. The Research center for Tumor Diagnosis and Therapeutical Physics & beijing Key {2.oratory of Medical Physics and Engineering, beijing 100871, china 2. Key {2.oratory of Pure and Applied Mathematics, School of Mathematical Sciences, Peking university, beijing 100871, china) beijing Key lab. of Med. Phys. and Eng. Res. Ctr. for Tumor Diagnosis and Therapeutical Phys. Beijing 100871 China Key lab. of Pure and Applied Math. Sch. of Math. Sci. Peking Univ. Beijing 100871 China

A novel scheme of external force for detecting the object boundary of medical image based on Snakes (active contours) is introduced in the paper. In our new method, an electrostatic field on a template plane above the original image plane is designed to form the map of the external force. Compared with the method of Gradient Vector Flow (GVF), our approach has clear physical meanings. It has stronger ability to conform to boundary concavities, is simple to implement, and reliable for shape segmenting. Additionally, our method has larger capture range for the external force and is useful for medical image preprocessing in various applications. Finally, by adding the balloon force to the electrostatic field model, our Snake is able to represent long tube-like shapes or shapes with significant protrusions or bifurcations, and it has the specialty to prevent Snake leaking from large gaps on image edge by using a two-stage segmentation technique introduced in this paper. The test of our models proves that our methods are robust, precise in medical image segmentation.

关键词： image segmentation eSnake external force electrostatic field balloon force.

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

Re-Os(ICP-MS)dating of the massive sulfide ores from the Jinchuan Ni-Cu-PGE deposit

引用

Science china Earth Sciences 2005年第10期48卷 1672-1677页

作者： YANG Gang1,2. DU Andao1, LU Jiren3, QU Wenjun1 & CHEN Jiangfeng2.1. National Research center of Geoanalysis, beijing 100037, {2. 2. laboratory for Earth Material Cycling, School of Earth and Space Sciences, university of Science and Technology of {2., Hefei 2.002., {2. 3. Institute of Mineral Resource, Chinese Academy of geological Sciences, beijing 100037, {2. National Research center of Geoanalysis university of Science and Technology of china Chinese Academy of geological Sciences

Massive sulfide ore from the Jinchuan Ni-Cu-PGE deposit was dated by Re-Os technique using Carius Tube digestion, Os distillation, Re extraction by acetone and ICP-MS measurement. An isochron giving an age of 833 ± 35 Ma, initial 187Os/188Os ratio of 0.2.9 ± 0.018 (MSWD = 1.7) and γOs = 130 ± 15 is obtained. The Re-Os age obtained agrees, within analytical uncertainties, with previous SHRIMP zircon U-Pb age of 82. ± 8 Ma (n=5, MSWD = 4.3). The result suggests that the deposit was formed at Neoproterozoic and that the formation of the Jinchuan Ni-Cu-PGE sulfide deposit may be closely related to the plume activity, which were attributed to the breakup of the Rodinia supercontinent. The high γOs of the massive ores sug-gests that crustal material was involved in the formation of the Jinchuan deposit, however, the quantity of the added crustal material is less than 10%.

关键词： Jinchuan Ni-Cu-PGE deposit, Re-Os dating, 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

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：