检索结果-南通市图书馆

A novel model of the carbon cycle in the Cambrian ocean

Science China Earth Sciences 2024年第6期67卷 1759-1778页

作者： Huajian WANG Shuichang ZHANG Xiaomei WANG Jin SU Yuntao YE Yuke LIU key laboratory of Petroleum Geochemistry Research Institute of Petroleum Exploration and DevelopmentChina National Petroleum CorporationBeijing 100083China key laboratory of orogenic belts and crustal evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China

The classic model of the carbon cycle suggests that the extensive burial of ^(12)C-enriched organic carbon leads to a positive carbon isotope(δ^(13)C)excursion(CIE),while massive oxidation of organic carbon results in a negative ***,global events such as the BAsal Cambrian Carbon isotope Excursion(BACE)and the Steptoean Positive Carbon Isotope Excursion(SPICE)are global negative and positive δ^(13)C excursions,respectively,and they also exhibit significant organic carbon burial anomalies,displaying decoupling between carbon isotope anomalies and organic carbon *** on the analyses of the Cambrian carbon cycle and paleoceanographic evolution records from well Tadong2 in the Tarim Basin,we propose a novel model of the carbon cycle in the Cambrian ocean that incorporates oceanic dissolved organic carbon(DOC).Our findings are as follows.(1)The Cambrian ocean maintained substantial DOC reservoirs,which were regulated by ocean currents and paleo-redox conditions and exerted significant influence on the oceanic carbon cycle.(2)The oxidation of the oceanic DOC reservoirs during the early Cambrian led to the BACE and the Asian Phenomenon of the Cambrian petroleum systems,while the expansion of the oceanic DOC reservoirs during the SPICE resulted in a global positive δ^(13)C excursion and the absence of significant organic carbon burial.(3)The deep-basin sedimentary environment in the eastern depression of the Tarim Basin may have fostered the development of organic-rich black shales during the Furongian Series,corresponding to organic carbon burial during the SPICE and representing potential prospects for ultra-deep oil and gas *** research should focus on the formation mechanism,reserve scale,and influencing factors of the oceanic DOC reservoirs,as well as their resource and environmental *** is expected that new breakthroughs will be made in the fields of Earth system science and oil and gas exploration.

关键词： Carbon isotope Organic carbon BACE SPICE Dissolved organic carbon Climate change Black shale

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

Three-stage niobium mineralization at Bayan Obo, China

引用

National Science Review 2024年第4期11卷 102-110页

作者： Yan Yu Yang Li Yu Liu Xiao-Xiao Ling Li-Guang Wu Li Yang Lan Yang Bo Yang Yong-Gang Zhao Xian-Hua Li State key laboratory of Lithospheric evolution Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth and Planetary Science University of Chinese Academy of Sciences ministry of education key laboratory of orogenic belts and crustal evolution School of Earth and Space SciencesPeking University Mining Research Institute Baotou Iron and Steel(Group) Co.LTD State key laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization

The Chinese Bayan Obo deposit is a world-class rare earth element(REE) deposit with considerable niobium(Nb) and iron(Fe) resources. A complete genetic understanding on all metals is fundamental for establishing genetic models at Bayan Obo. With extensive research being focused on REE enrichment, the timing and controls of Nb enrichment remain unresolved at Bayan Obo, which is mainly due to the challenges in dating, i.e. multistage thermal events, fine-grained minerals with complex textures and the rare occurrence of uranium-enriched minerals with mature dating methods. Based on robust geological and petrographic frameworks, here we conducted ion probe uranium-lead(U-Pb) dating of ferrocolumbite to unravel the timing, hence the genesis of Nb mineralization. Three types of hydrothermal ferrocolumbites—key Nb-bearing minerals—are identified based on their textures and mineral assemblages. They yield U-Pb ages of 1312 ± 47 Ma(n = 99), 438 ± 7 Ma(n = 93), and 268 ± 5 Ma(n = 19), respectively. In line with deposit geology, we tentatively link the first, second and third stage Nb mineralization to Mesoproterozoic carbonatite magmatism, ubiquitous early Paleozoic hydrothermal activity, and Permian granitic magmatism, respectively. While quantifying the contribution of metal endowment from each stage requires further investigation, our new dates highlight that multi-stage mineralization is critical for Nb enrichment at Bayan Obo, which may also have implications for the enrichment mechanism of Nb in REE deposits in general.

关键词： niobium mineralization U-Pb dating ferrocolumbite Bayan Obo

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

Microstructures,Deformation Mechanisms and Seismic Properties of Synkinematic Migmatite from Southeastern Tibet:Insights from the Migmatitic Core of the Ailao Shan-Red River Shear Zone,Western Yunnan,China

引用

Journal of Earth Science 2024年第4期35卷 1149-1169页

作者： Weiwei Ma Bo Zhang Fulong Cai Baoyou Huang Lei Zhang key laboratory of orogenic belts and crustal evolution School of Earth and Space SciencesPeking UniversityBeijing100871China Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing100085China

Seismic anisotropy originating within the continental crust is commonly used to determine the deformation and kinematic flow within active orogens and is attributed to regionally oriented mica or hornblende ***,naturally deformed rocks usually contain compositional layers(e.g.,parallel compositional banding).It is necessary to understand how both varying mineral contents and differing intensities of compositional layering influence the seismic properties of the deep *** this study,we analyzed the seismic response of migmatitic amphibolite with compositional banding *** present the microstructures,fabrics,calculated seismic velocities,and seismic anisotropies of mylonitic amphibolite from a horizontal shear layer preserved within the Ailao Shan-Red River shear zone,southwestern Yunnan,*** investigated sample is characterized by pronounced centimeter-scale compositional *** microstructures and fabrics suggest that migmatitic amphibolite rocks within deep crust may delineate regions of deformation-assisted,channelized,reactive,porous melt *** origin of compositional banding in the studied migmatitic amphibolite is attributed primarily to partial melting together with some horizontal shearing *** microfabrics and structures investigated in this study are considered to be typical for the base of active horizontal shear layers in the deep crust of southeastern *** responses are modeled by using crystal preferred orientations for minerals of the migmatitic amphibolite by applying the Voigt-Reuss-Hill homogenization *** P-wave and S-wave velocities are largely consistent in the various layers of the ***,seismic anisotropies of P-wave(AV_(p))and S-wave(AVs)are higher in the melanosomes(AV_(p)=5.6%,AV_(s)=6.83%)than those in the leucosomes and the whole rock(AV_(p)=4.2%–4.6%,AV_(s)=3.1%–3.2%).In addition,there is pronounced,S-wave splitting oblique to the foliation plane in the migm

关键词： deformation-assisted melt flow seismic anisotropy microstructure compositional banding migmatite deep crust southeastern 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

Effect of Iron on the Stability of Rhodochrosite at the Topmost Lower Mantle Conditions

引用

Journal of Earth Science 2024年第2期35卷 504-513页

作者： Tianlei Zhai Fei Qin Shengxuan Huang Shan Qin Yu Gong key laboratory of orogenic belts and crustal evolution Ministry of EducationSchool of Earth and Space SciencesPeking UniversityBeijing100871China School of Earth Sciences and Resources China University of GeosciencesBeijing100083China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China

Carbonates are viewed as the principal oxidized carbon carriers during subduction,and thus the stability of subducted carbonates has significant implications for the deep carbon *** we investigate the high pressure-temperature behaviors of rhodochrosite in the presence of iron up to∼34 GPa by in-situ X-ray diffraction and ex-situ Raman *** relatively low temperature below∼1500 K,MnCO_(3)breaks down into MnO and CO_(2).Upon heating to∼1800 K,however,the MnCO_(3)-Fe^(0)reactions occur with the formation of Mn_(3)O_(4),Fe^(O)and reduced carbon.A'three-stage'reaction mechanism is proposed to understand the kinetics of the carbon-iron-manganese redox *** results suggest that Fe^(0)can serve as a reductant to greatly affect the stability of rhodochrosite,which implies that the effect of Fe-metal should be seriously considered for the high pressure-temperature behaviors of other predominant carbonates at Earth's mantle conditions,particularly at depths greater than∼250 km.

关键词： deep carbon cycle rhodochrosite reduced mantle diamond formation high pressure tectonics geochemistry

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 Deep Mantle Source for the Late Neoarchean Metamorphosed Basalts in Eastern Hebei,North China Craton:Insights from Whole-Rock Geochemistry and Sm-Nd Isotopes,and Zircon U-Pb-Hf Isotopes

引用

Journal of Earth Science 2024年第1期35卷 29-40页

作者： Zhuang Li Chunjing Wei Chuan Yang Xi Zhang College of Geosciences China University of PetroleumBeijing 102249China MOE key laboratory of orogenic belts and crustal evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China China Transport Telecommunications and Information Center Beijing 100011China

The basalts within the greenstone belt worldwide serve as an ideal target to decipher the nature of Archean mantle sources and further to extend the understanding of the early stages of Earth's *** provide important insights into the issues,we carried out a detailed investigation of whole-rock geochemistry and Sm-Nd isotopes,and zircon U-Pb-Hf isotopes for the Late Neoarchean metamorphosed basalts in eastern Hebei,North China Craton.U-Pb isotopic dating using the LA-ICPMS on zircons reveals that the basalts in eastern Hebei erupted at ca.2.48-2.51 Ga and subsequently experienced multiple regional metamorphic events at 2477 and 1798 Ma,*** metamorphosed basalts are featured by low SiO_(2),MgO,K_(2)O+Na_(2)O,and high Fe O contents,endowed with the subalkaline and high-Fe tholeiitic *** radiogenic initial Nd and Hf isotope values and correlations among V,Ni and Cr contents strongly imply that the basalts experienced significant clinopyroxene and olivine fractionation and minor crustal contamination during magma *** are also characterized by the relatively low total REE contents and exhibit significant depletions to moderate enrichments in the LREE contents,indicating the derivation from a deep mantle source in an Archean proto-mantle plume setting.

关键词： zircon U-Pb-Hf isotopes geochemistry Late Neoarchean basaltic magmatism North China Craton Archean proto-mantle plume

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

Microstructures, Fabrics, and Seismic Properties of Mylonitic Amphibolites: Implications for Strain Localization in a Thickening Anisotropic Middle Crust of the North China Craton

引用

Journal of Earth Science 2024年第3期35卷 769-785页

作者： Siqi Liu Bo Zhang Jinjiang Zhang Jian Zhang Lei Guo Tao Wang Baoyou Hang Xiaorong Li key laboratory of orogenic belts and crustal evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China Department of Earth Sciences The University of Hong KongHong KongChina Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

Strain localization processes in the continental crust generate faults and ductile shear zones over a broad range of scales affecting the long-term lithosphere deformation and the mechanical response of faults during the seismic *** anisotropy originated within the continental crust can be applied to deduce the kinematics and structures within orogens and is widely attributed to regionally aligned minerals,e.g.,***,naturally deformed rocks commonly show various structural layers(e.g.,strain localization layers).It is necessary to reveal how both varying amphibole contents and fabrics in the structural layers of strain localization impact seismic property and its interpretations in terms of *** present microstructures,petrofabrics,and calculate seismic properties of deformed amphibolite with the microstructures ranging from mylonite to *** transition from mylonite to ultramylonite is accompanied by a slight decrease of amphibole grain size,a disintegration of amphibole and plagioclase aggregates,and amphibole aspect ratio increase(from 1.68 to 2.23),concomitant with the precipitation of feldspar and/or quartz between amphibole *** intensities of amphibole crystallographic preferred orientations(CPOs)show a progressively increasing trend from mylonitic layers to homogeneous ultramylonitic layers,as indicated by the JAm index increasing from 1.9–4.0 for the mylonitic layers and 4.0–4.8 for the transition layer,to 5.1–6.9 for the ultramylonitic *** CPO patterns are nearly random for plagioclase and *** amphibole aggregates in the amphibolitic mylonite deform by diffusion,mechanical rotation,and weak dislocation creep,and develop CPOs *** polymineralic matrix(such as quartz and plagioclase)of the mylonite and the ultramylonite deform dominantly by dissolution-precipitation,combined with weak dislocation *** mean P and S wave velocities are estimated to be 6.3 and 3.5 km/

关键词： amphibolitic mylonite microstructures petrofabrics seismic property middle crust rheology tectonics.

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

Neogene integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

引用

Science China Earth Sciences 2024年第4期67卷 1326-1359页

作者： Tao DENG Xiaomin FANG Qiang LI Shiqi WANG Feixiang WU Sukuan HOU Jiao MA Qigao JIANGZUO Danhui SUN Yan ZHENG Qinqin SHI Boyang SUN Lu LI key laboratory of Vertebrate evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China CAS Center for Excellence in Life and Paleoenvironment Beijing 100044China University of Chinese Academy of Sciences Beijing 100049China CAS Center for Excellence in Tibetan Plateau Earth Sciences and key laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China key laboratory of orogenic belts and crustal evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China

The remarkable uplift of the Tibetan Plateau in the Neogene had great impacts on the climate and environment of East Asia and even the ***,establishment of the Neogene stratigraphic framework of the Tibetan Plateau is of great significance to research in various fields of *** on marine sediments,the international chronostratigraphic system of the Neogene is divided into six stages in the Miocene and two stages in the *** the beginning of the Cenozoic,the share of terrestrial strata on continents has increased *** the Neogene,it had far exceeded that of marine strata,and almost all deposits on the Tibetan Plateau and its surrounding areas were terrestrial *** China,the Miocene includes five stages and the Pliocene includes two *** for the Tunggurian of the Miocene,which has a lower boundary at 15 Ma,the other stages have the same paleomagnetic definitions and time intervals as the corresponding international marine *** fossils play a very important role in the division and correlation of Cenozoic terrestrial strata,and rodent,carnivore,proboscidean,perissodactyl and artiodactyl fossils are especially important in Neogene terrestrial *** are many basins with well-exposed strata and abundant mammalian fossils in the Tibetan *** lower boundary stratotype sections of the Neogene Xiejian and Bahean stages are located respectively in the Xining and Linxia basins,and there are precise paleomagnetic dates in coordination with mammalian *** lower boundary stratotypes of other stages can also be effectively determined in the Tibetan *** first appearing mammalian genera in East Asia also appeared in the Tibetan Plateau and its surrounding areas,especially in the Linxia Basin on the northeast margin and in the Siwaliks on the southwest *** them,Prodeinotherium first appeared at the bottom of the Miocene in the Siwaliks,and the earliest Hipparion of the Old

关键词： Tibetan Plateau Neogene Terrestrial stratum Mammalian fossil Paleomagnetism

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

Late Mesozoic Exhumation of the Huangling Massif:Constraints on the evolution of the Middle Yangtze River

引用

Acta Geologica Sinica(English Edition) 2024年第1期98卷 250-264页

作者： SU Jianchao LIN Xu LI Chang’an Jolivet MARC WU Lin CHENG Feng DENG Bin WU Zhonghai CHEN Xiaokang HU Chengwei School of Geography and Information Engineering China University of GeosciencesWuhan 430074China College of Civil Engineering and Architecture China Three Gorges UniversityYichangHubei 443002China Géosciences Rennes CNRS-UMR6118Univ RennesRennesFrance State key laboratory of Lithospheric evolution Institute of Geology and GeophysicsChinese Academy of SciencesBejing 100029China key laboratory of orogenic belts and crustal evolution Ministry of EducationSchool of Earth and Space SciencesPeking UniversityBeijing 100871China State key laboratory of Oil and Gas Reservoir Geology and Exploitation/Chengdu University of Technology Chengdu 100871China Institute of Geological Mechanics Chinese Academy of Geological ScienceBeijing 100081China

Plate subduction leads to complex exhumation processes on *** Huangling Massif lies at the northern margin of the South China *** the Huangling Massif was exhumed as a watershed of the middle reaches of the Paleo-Yangtze River during the Mesozoic remains under *** examined the exhumation history of the Huangling Massif based on six granite bedrock samples,using apatite fission track(AFT)and apatite and zircon(U-Th)/He(AHe and ZHe)*** samples yielded ages of 157–132 Ma(ZHe),119–106 Ma(AFT),and 114–72 Ma(AHe),*** modeling revealed that three phases of rapid cooling occurred during the Late Jurassic–Early Cretaceous,late Early Cretaceous,and Late *** exhumation processes led to the high topographic relief responsible for the emergence of the Huangling *** integrated of our new data with published sedimentological records suggests that the Huangling Massif might have been the watershed of the middle reaches of the Paleo-Yangtze River since the *** that time,the rivers flowed westward into the Sichuan Basin and eastward into the Jianghan *** subduction of the Pacific Plate beneath the Asian continent in the Mesozoic deeply influenced the geomorphic evolution of the South China Block.

关键词： apatite zircon (U-Th)/He fission track Huangling Massif Yangtze River

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

Munabulake ophiolitic mélange:Implication for the evolution history of the north branch of the Proto-Tethys ocean

引用

Geoscience Frontiers 2024年第1期15卷 354-373页

作者： Changfeng Liu Wencan Liu Baoying Ye Zixian Zhao He Su Xin Xu China University of Geosciences(Beijing) Beijing 100083China Experimental School of Beijing Ritan High School Beijing 100123China The key laboratory of orogenic belts and crustal evolution Ministry of EducationSchool of Earth and Space SciencesPeking UniversityBeijing 100871China

One of the ophiolites that record the Proto-Tethys Ocean’s episodic closure is the Munabulake ophiolitic mélange,which is situated in the middle of the Kunlun-Qaidam and Altun-Qilian *** field mapping revealed that the Munabulake ophiolitic mélange comprises local(ultramafic rocks,basalts,andesites,gabbros,diorites,and plagiogranites)and exotic(marble,gneiss,schist,and amphibolite)blocks,many of which are in the schist matrix(Qimantage Group).Based on geochronological,geochemical,and petrological observations,the mafic rocks in the Munabulake ophiolitic mélange can be categorized into three categories:498-Ma OIB-like gabbros,468-Ma Hawaiian alkaline basalt-like dolerite and pillow basaltic slices,and 428 Ma massive SSZ-like ultramafic *** 501-452 Ma I-type granites exhibit arc affinities due to the oceanic crust *** findings,along with spatial relationships,suggest that the Early Paleozoic ophiolite complex,island arc rocks,and accretionary complex generated as an intra-oceanic arc system as a result of obduction of the south Altun Ocean’s onto the Central Altun block within a north-directed subduction event.A dextral strike-slip was evident throughout the Early Paleozoic oceanic crust subduction based on the whole set of planar and linear structural data,and the subduction polarity was likely to the *** to the ophiolitic mélange’s youngest rocks and the existence of 413 Ma granite dykes that are widely exposed in the Munabulake ophiolitic mélange,the Munabulake ophiolitic mélange was most likely emplaced during the Middle *** Munabulake ophiolitic mélange is similar in age and petrochemical characteristics to the other ophiolites in the South Altun subduction-collision belt,indicating that the Manabulak ophiolite mélange is a westward extension of the Apa-Mangya subduction-collision belt,which formed during the northward subduction of the South Altun Ocean slab during the Early ***,the final closing ti

关键词： Altun orogenic belt Munabulake Ophiolitic mé lange Early Paleozoic North-dipping subduction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Predicting Turbidite Channel in Deep-Water Canyon Based on Grey Relational Analysis-Support Vector Machine Model:A Case Study of the Lingshui Depression in Qiongdongnan Basin,South China Sea

引用

Energy Engineering 2024年第9期121卷 2435-2447页

作者： Haichen Li Jianghai Li Li Li Zhandong Li School of Earth and Space Sciences Peking UniversityBeijing100871China key laboratory of orogenic belts and crustal evolution Peking UniversityBeijing100871China Geotechnical Physical and Mechanical Properties laboratory Langfang Normal UniversityLangfang065000China Heilongjiang Northeast Petroleum University Science Park Development Co. Ltd.Daqing163318China College of Petroleum Engineering Northeast Petroleum UniversityDaqing163318China

The turbidite channel of South China Sea has been highly *** by the complex fault and the rapid phase change of lithofacies,predicting the channel through conventional seismic attributes is not accurate *** response to this disadvantage,this study used a method combining grey relational analysis(GRA)and support vectormachine(SVM)and established a set of prediction technical procedures suitable for reservoirs with complex geological *** the case study of the Huangliu Formation in Qiongdongnan Basin,South China Sea,this study first dimensionalized the conventional seismic attributes of Gas Layer Group I and then used the GRA method to obtain the main relational factors.A higher relational degree indicates a higher probability of responding to the attributes of the turbidite *** study then accumulated the optimized attributes with the highest relational factors to obtain a first-order accumulated sequence,which was used as the input training sample of the SVM model,thus successfully constructing the SVM turbidite channel *** results prove that the GRA-SVMmethod has a high drilling coincidence *** the core and logging data and taking full use of the advantages of seismic inversion in predicting the sand boundary of water channels,this study divides the sedimentary microfacies of the Huangliu Formation in the Lingshui 17-2 Gas *** comprehensive study has shown that the GRA-SVM method has high accuracy for predicting turbidite channels and can be used as a superior turbidite channel prediction method under complex geological conditions.

关键词： Support vector machine channel Huangliu Formation Qiongdongnan Basin

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

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：