|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Tectonics of South China Continent and its implications显示文摘This paper aims at exploring the tectonic characteristics of the South China Continent(SCC)and extracting the universal tectonic rules from these characteristics,to help enrich the plate tectonic theory and better understand the continental dynamic system.For this purpose,here we conduct a multi-disciplinary investigation and combine it with the previous studies to reassess the tectonics and evolution of SCC and propose that the tectonic framework of the continent comprises two blocks,three types of tectonic units,four deformation systems,and four evolutionary stages with distinctive mechanism and tectonic characteristics since the Neoproterozoic.The four evolutionary stages are:(1)The amalgamation and break-up of the Neoproterozoic plates,typically the intracontinental rifting.(2)The early Paleozoic and Mesozoic intracontinental orogeny confined by plate tectonics,forming two composite tectonic domains.(3)The parallel operation of the Yangtze cratonization and intracontinental orogeny,and multi-phase reactivation of the Yangtze craton.(4)The association and differentiation evolution of plate tectonics and intracontinental tectonics,and the dynamic characteristics under the Meso-Cenozoic modern global plate tectonic regime. | ZHANG GuoWei GUO AnLin WANG YueJun LI SanZhong DONG YunPeng LIU ShaoFeng HE DengFa CHENG ShunYou LU RuKui YAO AnPing | 2013 | Science China Earth Sciences2013，56，11： | 88 |
| 2 | Structure and deformation around the Gyirong basin, north Himalaya, and onset of the south Tibetan detachment system显示文摘Gyirong basin and its adjacent area are located at a special position in the Himalayan orogen, where the south Tibetan detachment system (STDS) and N-S trending rift converged. The north Himalayan orogen here can be divided into five petrologic-tectonic units successively from south to north: 1) the Greater Himalayan crystalline complex (GHC); 2) the STDS shear zone; 3) the Tethyan Himalayan sedimentary sequence (THS); 4) the late Cenozoic sedimentary basins, such as Gyirong and Oma basins; and 5) the Malashan gneiss dome. Structural studies show that this area experienced four stages of deformation: 1) the earlier south-directed thrusting, preserved both in the GHC and THS; 2) top-down-to-north slip along the STDS, normal faults related to this slip formed the early controlling structures of the Cenozoic basins,and the tilted pattern of the blocks between the basins indicated a north-directed slip; 3) east-west extension, the resultant N-S trending normal fault formed the eastern boundary of the basins; and 4) late gravitational collapse. Zircon SHRIMP U-Pb dating on the syn-deformational (leuco-) granite along the STDS indicates that the major activity of the STDS occurred at ca. 26 Ma, but its onset may have begun as early as ca. 36 Ma. | YANG XiongYing ZHANG JinJiang QI GuoWei WANG DeChao GUO Lei LI PengYuan LIU Jiang | 2009 | Science China Earth Sciences2009，52，8： | 33 |
| 3 | Hypoxic preconditioning stimulates angiogenesis in ischemic penumbra after acute cerebral infarction显示文摘Previous studies have demonstrated the protective effect of hypoxic preconditioning on acute cerebral infarction,but the mechanisms underlying this protection remain unclear.To investigate the protective mechanisms of hypoxic preconditioning in relation to its effects on angiogenesis,we induced a photochemical model of cerebral infarction in an inbred line of mice(BALB/c).Mice were then exposed to hypoxic preconditioning 30 minutes prior to model establishment.Results showed significantly increased vascular endothelial growth factor and CD31 expression in the ischemic penumbra at 24 and 72 hours post infarction,mainly in neurons and vascular endothelial cells.Hypoxic preconditioning increased vascular endothelial growth factor and CD31 expression in the ischemic penumbra and the expression of vascular endothelial growth factor was positively related to that of CD31.Moreover,hypoxic preconditioning reduced the infarct volume and improved neurological function in mice.These findings indicate that the protective role of hypoxic preconditioning in acute cerebral infarction may possibly be due to an increase in expression of vascular endothelial growth factor and CD31 in the ischemic penumbra,which promoted angiogenesis. | Sijie Li Yanbo Zhang Guo Shao Mingfeng Yang Jingzhong Niu Guowei Lv Xunming Ji | 2013 | Neural Regeneration Research2013，8，31： | 31 |
| 4 | Thinning and destruction of the cratonic lithosphere:A global perspective显示文摘It has been proposed that the North China Craton(NCC)was thinned up to a thickness of>100 km during the Phanerozoic,and underwent an associated craton destruction.Evidently,it is an important topic worthy of future study to understanding the mechanism of cratonic destruction and its role played in the continental evolution.After synthesized the global cratons of India,Brazil,South Africa,Siberia,East Europe(Baltic)and North America,we found that lithospheric thinning is common in the cratonic evolution,but it is not always associated with craton destruction.Most cratons was thinned by thermal erosion of mantle plume or mantle upwelling,which,however,may not cause craton destruction.Based on the studies of the North American and North China Cratons,we suggest that oceanic subduction plays an important role in caton destruction.Fluids or melts released by dehydration of the subducted slabs metasomatize the mantle wedge above and trigger extensive partial melting.More importantly,the metasomatized mantle lost its original rigidity and make craton easier to be deformed and then to be destoyed.Therefore,we suggest that the widespread crust-derived granite and large-scale ductile deformation within the continental crust can be regarded as the petrological and structural indicators of craton destruction,respectively. | WU FuYuan XU YiGang ZHU RiXiang ZHANG GuoWei | 2014 | Science China Earth Sciences2014，57，12： | 33 |
| 5 | Geochemistry and regional distribution of ophiolites and associated volcanics in Mianlüe suture, Qinling-Dabie Mountains显示文摘Systematic studies of the ophiolites and associated volcanics stretching more than 1500 km from the Derni-Nanping-Pipasi-Kangxian area in the west to the Qingshuihe area of the south Dabie Mountains in the east indicate the existence of a suture zone (the Mianl黣 suture) and a vanished paleo-ocean basin (the Mianl黣 paleo-ocean basin) in the region. From west to east, ophiolitic mlange associations distribute discontinuously along the suture. Rock assem-blages include ophiolite, island arc and oceanic island rock series. The Mianl黣 paleo-ocean basin experienced its major formation and expending episode during the Carboniferous-Permian period. The finding of the suture zone and the paleo-ocean basin is tectonically significant in timing the collision between the North China-Qinling and Yangtze blocks and determining the formation and evolution of the Qinling orogenic belt. | LAI Shaocong, ZHANG Guowei, DONG Yunpeng, PEI Xianzhi & CHEN Liang Key Laboratory of Continental Dynamics, Ministry of Education and Department of Geology, Northwest University, Xian 710069, China | 2004 | Science China Earth Sciences2004，47，4： | 25 |
| 6 | Geochemical Features of Ophiolite in Mianxian Lueyang Suture Zone,Qinling Orogenic Belt显示文摘GeochemicalFeaturesofOphioliteinMianxianLueyangSutureZone,QinlingOrogenicBeltLaiShaocong;ZhangGuowei(DepartmentofGeology,Nort... | Lai Shaocong Zhang Guowei(Department of Geology, Northwest University, Xi’an 710069) | 1996 | Journal of Earth Science1996，15，2： | 22 |
| 7 | Climate and litter C/N ratio constrain soil organic carbon accumulation显示文摘Soil organic carbon(SOC) plays critical roles in stabilizing atmospheric CO2 concentration, but the mechanistic controls on the amount and distribution of SOC on global scales are not well understood. In turn, this has hampered the ability to model global C budgets and to find measures to mitigate climate change. Here, based on the data from a large field survey campaign with 2600 plots across China’s forest ecosystems and a global collection of published data from forested land, we find that a low litter carbon-to-nitrogen ratio(C/N) and high wetness index(P/PET, precipitation-to-potentialevapotranspiration ratio) are the two factors that promote SOC accumulation, with only minor contributions of litter quantity and soil texture. The field survey data demonstrated that high plant diversity decreased litter C/N and thus indirectly promoted SOC accumulation by increasing the litter quality. We conclude that any changes in plant-community composition, plant-species richness and environmental factors that can reduce the litter C/N ratio, or climatic changes that increase wetness index, may promote SOC accumulation. The study provides a guideline for modeling the carbon cycle of various ecosystem scales and formulates the principle for land-based actions for mitigating the rising atmospheric CO2 concentration. | Guoyi Zhou Shan Xu Philippe Ciais Stefano Manzoni Jingyun Fang Guirui Yu Xuli Tang Ping Zhou Wantong Wang Junhua Yan Gengxu Wang Keping Ma Shenggong Li Sheng Du Shijie Han Youxin Ma Deqiang Zhang Juxiu Liu Shizhong Liu Guowei Chu Qianmei Zhang Yuelin Li Wenjuan Huang Hai Ren Xiankai Lu Xiuzhi Chen | 2019 | National Science Review2019，6，4： | 21 |
| 8 | Process of Rifting and Collision along Plate Margins of the Qinling Orogenic Belt and Its Geodynamics显示文摘The Qinling erogenic belt underwent complicated processes of rifting and collision, as shown by the coexistence of (1) ocean extension and plate margin rifting and (2) subduction of the frontal oceanic crust and extension of the rear plate margin. These resulted in a basin-mountain framework characterized by the coexistence of plates separated by the ocean basin and continental blocks demarcated by the rifting sea trough in the marginal region and the coexistence of subduction orogeny and ocean extension. Generally speaking, the plate marginal area between the North China plate and Yangtze plate continually rifted from north to south and the rifted micro-plates continually accreted northwards. This especial orogenic process was probably controlled by two events of deep mantle geody-namic adjustment and mantle plume activities, which occurred in the Shangdan suture belt and Mianlue suture belt from north to south respectively. | LIU Shaofeng ZHANG Guowei | 1999 | Acta Geologica Sinica(English Edition)1999，73，3： | 20 |
| 9 | Age of Anzishan granulites in the Mianxian-Lueyang suture zone of Qingling orogen:With a discussion of the timing of final assembly of Yangtze and North China craton blocks显示文摘Many granulite blocks have been recently dis-covered in the Anzishan area, Mianxian County, ShaanxiProvince, in the central segment of the Manxian-Lueyangsuturc zone. Sm-Nd isochron and 40 Ar39 Ar ages of mineralsamples of granulites from this area are reported in the note.The granulite mineral samples give a Sm-Nd isochron age oft=(206 ± 55) Ma (2σ), with INd = 0.51302±7(2σ) and MSWD =1.6, and a biotite 40Ar/39 Ar plateau age of (199.7±l.7) Ma(2σ). The formation and uplift of the granulites were relatedto subduction of the Yangtze block beneath the SouthQinling microcontinent and their collision and the finalamalgamation of the Yangtze and Sino-Korean craton blocksin the Indosinian, and their age is consistent with or close tothose of the Dabie ultrahigh-pressure and high-pressuremetamorphic rocks, so have great tectonic significance. | ZHANG Zongqing ZHANG Guowei TANG SuohaiV XU Jifeng YANG Yongcheng WANG Jinhui | 2002 | Chinese Science Bulletin2002，47，22： | 19 |
| 10 | Zircon SHRIMP U-Pb ages and trace element geochemistry of the Kuhai gabbro and the Dur'ngoi diorite in the southern east Kunlun tectonic belt, Qinghai, Western China and their geological implications显示文摘Timing of the intermediate-basic igneous rocks developed in the area of Kuhai-A'nyêmaqên along the southern east Kunlun tectonic belt is a controversial issue. This paper presents new zircon SHRIMP U-Pb dating data for igneous zircons from the Kuhai gabbro and the Dur'ngoi diorite in the Kuhai-A'nyemaqen tectonic belt, which are 555±9 Ma and 493±6 Ma, respectively. The trace element geochemical features of the Kuhai gabbro and the Dur'ngoi diorite are similar to those of ocean island basalts (OIB) and island arc basalts (IAB), respectively. Thus, the Kuhai gabbro with the age of 555±9 Ma and OIB geochemical features is similar to the Yushigou oceanic ophiolite in the North Qilian orogen, whereas the Dur'ngoi diorite with the age of 493±6 Ma and IAB geochemical features is similar to the island arc volcanic rocks developed in the north Qaidam. The Late Neoproterozoic to Early Ordovician ophiolite complex in the area of Kuhai-A'nyêmaqên suggests that the southern margin of the 'Qilian-Qaidam-Kunlun' archipelagic ocean in this period was located in the southern east Kunlun tectonic belt. Therefore, the southern east Kunlun tectonic belt in the early Paleozoic is not comparable to the Mianlüe tectonic belt in the Qinling orogenic belt. | LI WangYe LI ShuGuang GUO AnLin SUN YanGui ZHANG GuoWei | 2007 | Science China Earth Sciences2007，50，z2： | 17 |
| 11 | Cenozoic basin development and its indication of plateau growth in the Xunhua-Guide district显示文摘The Xunhua, Guide and Tongren Basins are linked with the Laji Mountain and the northern West Qinling thrust belts in the Xunhua-Guide district. Basin depositional stratigraphy consists of the Oligocene Xining Group, the uppermost Oligocene-Pliocene Guide Group and the Lower Pleistocene. They are divided into three basin phases by unconformities. Basin phase 1 is composed of the Xining Group, and Basin phase 2 of the Zharang, Xiadongshan, Herjia and Ganjia Conglomerate Formations in the Guide Group, and Basin phase 3 of the Gonghe Formation and the Lower Pleistocene. Three basin phases all develop lacustrine deposits at their lower parts, and alluvial-braided channel plain depositional systems at upper parts, which constitute a coarsening-upward and progradational sequence. Basin deposition, paleocurrent and provenance analyses represent that large lacustrine basin across the Laji Mountain was developed and sourced from the West Qinling thrust belt during the stage of the Xining Group (Basin phase 1), and point-dispersed alluvial fan-braided channel plain deposition systems were developed beside the thrust and uplifted Laji Mountain and sourced from it, as thrusting migrated northwards during the stage of the Guide Group (Basin phase 2). Evolution of basin-mountain system in the study area significantly indicates the growth process of the distal Tibetan Plateau. The result shows that the Tibetan Plateau expanded to the northern West-Qinling at Oligocene (29―21.4 Ma) by means of northward folded-and-thrust thickening and uplifting and frontal foreland basin filling, and across the study area to North Qilian and Liupan Mountain at the Miocene-Pliocene (20.8―2.6 Ma) by means of two-sided basement-involved-thrust thickening and uplifting and broken foreland basin filling, and the distant end of Tibetan Plateau behaved as regional erosion and intermontane basin aggradational filling during the Pliocene and early Pleistocene (2.6―1.7 Ma). | LIU ShaoFeng ZHANG GuoWei P.L.HELLER | 2007 | Science China Earth Sciences2007，50，z2： | 17 |
| 12 | The LA-ICP-MS zircons U-Pb ages and geochemistry of the Baihua basic igneous complexes in Tianshui area of West Qinling显示文摘Baihua meta-igneous complex consists mainly of pyroxenite-gabbro(diorite)-diorite-quartz diorite. They form a complete comagmatic evolutionary series. The geochemical characteristics of basic-interme- diate basic igneous rocks indicate that they belong to a tholeiite suite. The REE distribution pattern is nearly flat type and LREE is slightly enriched type, and their primitive mantle-normalized and MORB-normalized trace element spider diagrams are generally similar; the LIL elements (LILE) Cs, Ba, Sr, Th and U are enriched, but Rb, K and the HFSEs Nb, P, Zr, Sm, Ti and Y are relatively depleted. All these show comagmatic evolution and origin characteristics. The tectonics environment discrimination of trace element reveals that these igneous complexes formed in an island-arc setting. The LA-ICP-MS single-zircons U-Pb age of Baihua basic igneous complex is 434.6±1.5 Ma (MSWD = 1.3), which proves that the formation time of the island-arc type magmatite in the northern zone of West Qinling is Late Ordovician or Early Silurian, also reveals that the timing of subduction of paleo-ocean basin represented by the Guanzizhen ophiolite and resulting island-arc-type magmatic activities is probably Middle-Late Ordovician to Early Silurian. | PEI XianZhi DING SaPing ZHANG GuoWei LIU HuiBin LI ZuoChen LI GaoYang LIU ZhanQing MENG Yong | 2007 | Science China Earth Sciences2007，50，z2： | 15 |
| 13 | Coupling mechanism of roof and supporting wall in gob-side entry retaining in fully-mechanized mining with gangue backfilling显示文摘We analyzed the deformation characteristics of overlying stratum in backfilling with fully-mechanized and retaining roadways along the gob area coal mining technology, and established a mechanical model for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fully- mechanized coal mining technology. Using Winkler elastic foundation theory, we analyzed a part of the key stratum under the action of elastic foundation coupling problem, and derived deflection analyt- ical expressions. Combined with specific conditions, we obtained the deflection curves for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fully-mechanized coal mining technology. On this basis, we adopted the Coulomb's earth pressure theory to solve the problem of lateral pressure of the gangue filling area on the supporting wall beside the roadway and to provide the theoretical basis for reasonable selection of the distance between gangue concrete wall and roof and fur- ther discussion on the supporting stability of roadway. | Ma Zhanguo Gong Peng Fan Jinquan Geng Minmin Zhang Guowei | 2011 | Mining Science and Technology2011，21，6： | 15 |
| 14 | Underwater explosion in centrifuge partⅠ:Validation and calibration of scaling laws显示文摘Centrifuge is a promising tool for underwater explosion(UNDEX) research as both Mach and Froude similitudes could be satisfied with hyper-gravity in models, which would result in similarities in both shock wave and bubble oscillation. Scaling laws for UNDEX in centrifuge have been proposed based on dimensional analysis. Two dimensionless numbers, i.e.,π_3 and π_4, are used to characterize shock wave and bubble oscillation, respectively. To validate scaling laws, 17 UNDEX tests are designed by varying accelerations or explosive weights and positions in centrifuge. The tests are classified into different groups to validate scaling laws as well as calibrate coefficients in empirical formulae for both shock wave and bubble oscillation. The results show that changes of gravity acceleration or hydrodynamic pressure almost has no influence on shock wave peak pressure and time constant as long as π3 is constant. The dimensionless bubble period and maximum radius agreed with each other when π4 is constant. Based on the research, an example is exhibited to suggest method for the computation of initial loading conditions for a submerged obstacle subjected to UNDEX. | HU Jing CHEN ZuYu ZHANG XueDong WEI YingQi LIANG XiangQian LIANG JianHui MA GuoWei WANG QiuSheng LONG Yuan | 2017 | Science China(Technological Sciences)2017，60，11： | 14 |
| 15 | Geochemistry of the ophiolite and oceanic island basalt in the Kangxian-Pipasi-Nanping tectonic mélange zone, South Qinling and their tectonic significance显示文摘Detailed studies indicate that Kangxian-Pipasi-Nanping tectonic zone is a complicated mélange zone which includes many tectonic slabs of different origins. Ophiolite (MORB-type basalt), oceanic island tholeiite and alkaline basalt have been identified. Moreover, this tectonic mélange zone is eastward connected with the Mianlüe suture zone. The deformation characteristics, consisting components and volcanic rock geochemical features for the Kangxian-Pipasi-Nanping tectonic mélange zone are much similar to those of the Mianlüe suture zone and Deerni ophiolite. Therefore, the Kangxian-Pipasi-Nanping tectonic mélange zone should be the westward extension part of the Mianlüe suture zone. It indicates that the Mianlüe suture zone had extended to the Nanping area. | LAI Shaocong ZHANG Guowei PEI Xianzhi YANG Haifeng | 2004 | Science China Earth Sciences2004，47，2： | 13 |
| 16 | Mesozoic basin development and its indication of collisional orogeny in the Dabie orogen显示文摘The Dabie orogen underwent deep continental subduction, rapid exhumation, and the huge amount of erosion during the Mesozoic. Its tectonic evolution, especially how its evolution was recorded by sedimentary basins at the flanks of the Dabie orogen is one of the most important issues of the world's attention. These years, newly studies of basin sedimentology, combined with structural geology, have shown a fundamental progress. The overall distribution of different basin types in the orogen indicates that shortening and thrusting at the margins of the orogen from the Late Triassic to the Early Cretaceous controlled the foreland basins, and extension, doming and rifting were initiated in the core of the orogen from the Jurassic to the Early Cretaceous and were expanded to the whole orogen after the Late Cretaceous. Therefore, The Dabie orogen records gradual transition from overall shortening and thrusting to dominantly extension and rift basin formation expanded from its core to its margins, although these shortening and extension overlapped in time from the Jurassic through Early Cretaceous at crustal levels. The unroofing ages of the ultra-high pressure (UHP) metamorphic rocks in the Dabie orogen change from Early Jurassic to Late Jurassic westward. The depth of exhumation increases eastwards. The sediment sources for the Hefei basin are mostly composed of the deeply exhumed, axial Dabie metamorphic complex, and the sediment sources for the Middle Yangtze basin are mostly from cover strata in the southern orogen and related strata with subjacent (i.e. subsequently overthrusted) Mianlue suture belt. Geodynamic analysis represents that continental collision between the North China Block and the South China Block along the Shangdan and Mianlue sutures, subsequently northwestward progradation of the Jiangnan fold and thrust belt, and the underthrusting of the North China Block along the Northern Boundary Fault of Qinling Range led to crustal thickening, gravitational spreading and balanced rebound of the resultant thick crustal welt, and multi-episodic exhumation of the HP/UHP metamorphic rocks. The future studies by the methods of tracing the Dabie orogeny through deposition in the marginal basins should focus on eastward extension of the Mianlue suture, thrust and overlap of the Dabie HP/UHP metamorphic block on different lithotectonic zones and basins along the northern South China Block, the structural framework of the source area of the basins in the syn-depositional stage, the basin lateral extension, huge amount of erosion and sediment transportation from the Dabie blanket and basement rocks, and recovery of subducted and re- moved structural units within the Dabie orogen, etc. | LIU ShaoFeng ZHANG GuoWei | 2013 | Chinese Science Bulletin2013，58，8： | 12 |
| 17 | Geochemistry of the subduction-related magmatic rocks in the Dahong Mountains, northern Hubei Province--Constraint on the existence and subduction of the eastern Mianlüe oceanic basin显示文摘The existence and subduction of the eastern Mianl黣 oceanic basin in the south Qinling belt are keys to understand the Qinling orogen. Based on geological mapping, several volcanic slices have been identified in Tumen, Zhoujiawan, Xiaofu and Yuantan areas, which distribute in the northern margin of the Dahong Mountains (DHM), and thrust into the Sanli-gang-Sanyang fault. These slices consist mainly of diabases, basaltic-andesitic lavas, pyroclastic rocks and a minor tuff. The geochemistry of the basalts, andesites,and diabases is characterized by depleting in Nb and Ta, enriching in Th and LILE (e.g.K, Rb, Ba), and undifferentiating in HFSE. These geochemical characteristics suggest that the original magma of these rocks was derived from a mantle wedge above a subduction zone, and formed in an island-arc setting in Carboniferous-early Triassic. Comparing with the ophiolites and island-arc volcanic rocks in Mianxian-Leyang area to the west, it is reasonable to consider that there had been an oceanic basin connecting with the Mianle ancient ocean to the westward, distributing along the south edge of the Tongbai-Dabie block. In view of the ophiolite in Huashan area and these island-arc volcanic rocks along the north of the Dahong Mountains, it is suggested that there had been a plate tectonic evolutionary history with oceanic basin rifting and subduction in this region. | DONG Yunpeng, ZHANG Guowei, ZHAO Xia, YAO Anping & LIU Xiaoming The Key Laboratory of Continental Dynamics, Ministry of Education, Department of Geology, Northwest University, Xi抋n 710069,China | 2004 | Science China Earth Sciences2004，47，4： | 12 |
| 18 | Ore-forming event and geodynamic setting of molybdenum deposit at Wenquan in Gansu Province,Western Qinling显示文摘The Wenquan molybdenum deposit is associated with a Triassic granite in this area.The Wenquan granite is enriched in LILE and LREE,poor in HFSE,and has significantly higher contents of alkali(K2O+Na2O) and Sr,Ba than those of the island arc volcanic rocks.These geochemical characteristics are similar to post-collisional granites in high K calc-alkaline series.Studies of major elements,trace elements,REEs and chronology of the Wenquan pluton show that,in the geodynamic transition stage of continent-continent convergence to extension,the partial melting of the enriched lithospheric mantle generated the basaltic magma and triggered the partial melting of the thickened lower crust which produceded the acidic magma,and the Wenquan pluton was formed by mixing of the two magmas.Molybdenite Re-Os isotopic dating gave Os model ages of 212.7±2.6 Ma to 215.1±2.6 Ma with a weighted mean of 214.1±1.1 Ma,and an Re-Os isochron age of 214.4±7.1 Ma.These ages are close to K-Ar ages(223 to 226 Ma) and a SHRIMP zircon U-Pb age(223±7 Ma) for the Wenquan granite within the error range,but relatively younger.This implies that the Mo mineralization occurred in a late stage of the magmatic intrusion,and the metallogenesis took place in the transition stage from syn-collision to post-collision in the tectonic setting of the Qinling Orogenic Belt(QOB) after continental collision be-tween the North China Block(NCB) and the South China Block(SCB).This process is also corre-sponding to the geological events of metamorphism and deformation in South Qinling,closure of the Mian-Lue oceanic basin,and exhumation of the Dabie-Sulu ultrahigh-pressure metamorphic rocks.The large-scale continent-continent collision between NCB and SCB in the middle Triassic triggered sig-nificant crustal thickening and exhumation of subducted slab.In the late Triassic,the tectonic setting was transformed to the transition stage from collision to extension.Materials from the asthenospheric mantle would ascend into the root of the lower crust,which could induce partial melting of the lower crust and generate Mo-enriched granitic magma.The ore-forming elements enriched in the fluid derived from the condensation and fraction of the magma resulted in the Mo mineralization.The Mo deposits in the QOB are mainly formed in two episodes,namely 220± Ma and 140± Ma.The two episodes of metal-logenesis were developed in the tectonic transition settings from compression to extension,but they were in the different stages of the tectonic evolution.The occurrence of the Wenquan Mo-bearing plu-ton indicates that the Triassic tectonic-magmatic belt of Western Qinling is another favorable region for Mo mineralization in the QOB.Therefore,it is significant to pay more attention to evaluation of the ore-forming potentiality in the Triassic granites in Western Qinling. | ZHU LaiMin DING ZhenJu YAO ShuZhen ZHANG GuoWei SONG ShiGang QU WenJun GUO Bo LEE Ben | 2009 | Chinese Science Bulletin2009，54，13： | 12 |
| 19 | Deep seismic sounding data reveal the crustal structures beneath Zoigê basin and its surrounding folded orogenic belts显示文摘Songpan-Garze massif is located at the turning position of tectonics from the nearly west-east direction to the nearly north-south direction in the northeastern margin of Tibetan Plateau,with Zoigê basin in the centre of the massif.In this paper,we build a crustal structure model of Zoigê basin and its surrounding folded orogenic belts using the deep seismic sounding data in this region.We also discuss structures and properties of the basement in Zoigê basin,tectonic relations between Zoigê upland basin and its surrounding folded orogenic belts,crustal deformation and thickening in the northeastern margin of Tibetan Plateau,and decoupling and relaxing processes in the crust.The results indicate that a special 'Mesozoic basement' is formed of Triassic rocks with high density (2.65-2.75 g/cm3) and high velocity (5.6 km/s) in Zoigê basin.Songpan-Garze tectonic massif was transformed into two types of tectonic units with different crustal structures,i.e.,relatively stable Zoigê upland basin and active folded orogenic belts around the basin,in the course of the crustal material of Tibetan Plateau flowing eastward and obstructed by surrounding stable blocks.The thickening of the crust in the northeastern margin of Tibetan Plateau mainly occurred in the mid and lower crust,and the structure characterized by low velocities and multiple reflectors obviously appears in the folded orogenic belts around Zoigê basin.It implies that the mid and lower crust underwent a strong tectonic deformation in the folded orogenic areas.The thickness of the crust is about 50 km in Zoigê basin and the folded orogenic belts at the both southern and northern sides of Zoigê basin.The 'Mountain root' cannot be identified.It is inferred that during the later orogenic period the eastwards flowing deep materials moved clockwise along the relatively relaxing southern side around the eastern tectonic knot under the obstructing of surrounding rigid massifs,and it resulted in the strong stretching action of the folded orogenic belts around Zoigê basin. | JIA ShiXu,ZHANG XianKang,ZHAO JinRen,WANG FuYun,ZHANG ChengKe,XU ZhaoFan,PAN JiShun,LIU Zhi,PAN SuZhen & SUN GuoWei Geophysical Exploration Center,China Earthquake Administration,Zhengzhou 450002,China | 2010 | Science China Earth Sciences2010，53，2： | 11 |
| 20 | Geochemistry and spatial distribution of OIB and MORB in A’nyemaqen ophiolite zone: Evidence of Majixue-shan ancient ridge-centered hotspot显示文摘The mafic volcanic association is made up of OIB, E-MORB and N-MORB in the A'nyemaqen Paleozoic ophiolites. Compared with the same type rocks in the world, the mafic rocks generally display lower Nb/U and Ce/Pb ratios and some have Nb depletion and Pb enrichment. The OIB are LREE-enriched with (La/Yb)N =5―20, N-MORB are LREE-depleted with (La/Yb)N = 0.41―0.5. The OIB are featured by incompatible element enrichment and the N-MORB are obviously depleted with some metasomatic ef- fect, and E-MORB are geochemically intermediated. These rocks are distributed around the Majixue- shan OIB and gabbros in a thickness greater than a thousand meters and transitionally change along the ophiolite extension in a west-east direction, showing a symmetric distribution pattern as centered by the Majixueshan OIB, that is, from N-MORB, OIB and E-MORB association in the Dur'ngoi area to OIB in the Majixueshan area and then to N-MORB, OIB and E-MORB assemblage again in the Buqing- shan area. By consideration of the rock association, the rock spatial distribution and the thickness of the mafic rocks in the Majixueshan, coupled with the metasomatic relationship between the OIB and MORB sources, it can be argued that the Majixueshan probably corresponds to an ancient hotspot or an ocean island formed by mantle plume on the A'nyemaqeh ocean ridge, that is the ridge-centered hotspot, tectonically similar to the present-day Iceland hotspot. | GUO AnLin ZHANG GuoWei SUN YanGui ZHENG JianKang LIU Ye WANG JianQi | 2007 | Science China Earth Sciences2007，50，2： | 11 |
您所在的机构暂未开通此部分的功能，请联系管理员