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Archaean Greenstone Belts in China 被引量:1
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作者 Shen Baofeng, Peng Xiaoliang, Luo Hui and Mao DebaoTianjin Institute of Geology, Ministry of Geology and Mineral Resources, Tianjin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1994年第1期15-29,共15页
Chinese Achaean greenstone belts are mainly distributed along the northern and southwestern margins of the North China platform. In terms of their geological characteristics, the greenstone belts in China are comparab... Chinese Achaean greenstone belts are mainly distributed along the northern and southwestern margins of the North China platform. In terms of their geological characteristics, the greenstone belts in China are comparable to those in other countries but at the same time have unique features of their own. In view of their geochemistry, the Chinese greenstone belts may be grouped into three types: the Jiapigou type, Qingyuan type and Xiaoqinling type. The greenstone belts were formed possibly in a rift-type palaeo-tectonic setting, similar to that of the modern island are-continental margin mobile belts. 展开更多
关键词 Archaean greenstone belts types of greenstone belts rift type tectonic setting China
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Geochemistry of metasedimentary rocks of the Sonakhan and Mahakoshal greenstone belts,Central India:Implications for paleoweathering,paleogeography and mechanisms of greenstone belt development
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作者 Hamidullah Wani M.E.A.Mondal Iftikhar Ahmad 《Acta Geochimica》 EI CAS CSCD 2022年第1期64-83,共20页
A comparative study of the Precambrian Sonakhan(SGB)and Mahakoshal(MGB)greenstones belts of Central India has been undertaken to decipher their provenance,paleoweathering,paleogeography,and tectonics.As compared to th... A comparative study of the Precambrian Sonakhan(SGB)and Mahakoshal(MGB)greenstones belts of Central India has been undertaken to decipher their provenance,paleoweathering,paleogeography,and tectonics.As compared to the Upper Continental Crust(UCC),the MGB samples are enriched while the SGB samples are depleted in mafic elements indicating the presence of mafic rocks in the source of the MGB.This is complemented by the Ni–Cr diagram.The REE concentrations,LREE fractionated patterns and negative Eu anomalies of the MGB and SGB samples indicate derivation of sediments from a highly fractionated granitic source.Since MGB samples also contain the geochemical signature of mafic rocks,it is,therefore proposed that the MGB clastic load were derived from two sources(mafic+felsic)with arc character.This is attested by Cr and Zr relationships,and LILE enrichment,and HFSE depletion.These features suggest that the SGB developed as autochthonous while the MGB developed as an allochthonous belt.The chemical alteration indices such as chemical index of alteration(CIA),plagioclase index of alteration(PIA),and index of compositional variability for MGB samples indicate that they were dominantly derived as the first cycle(with minor recycled)sediments from bimodal sources(dominantly continental arcs)by intense chemical weathering as compared to the SGB samples,which were derived from felsic sources(dominantly cratonic rocks),and partly by recycling through a low chemical weathering.The CIA and PIA values of the samples reveal a change in the climatic conditions from Late Archean to Late Paleoproterozoic.Such change is interpreted in terms of migration of the Indian plate from high latitudes in the Late Archean to lower latitudes during the Late Paleoproterozoic.This is consistent with the paleomagnetic data that placed India in the configuration of 2.45 Ga Ur and 1.78 Ga Columbia supercontinents. 展开更多
关键词 Central Indian Shield Sonakhan and Mahakoshal greenstone belts Paleoweathering and paleogeography Greenstone belt development
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A Metallogenic Model of Gold Deposits of the Jiaodong Granite-Greenstone Belt 被引量:65
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作者 DENGJun YANGLiqiang +2 位作者 SUNZhongshi WANOJianping WANGQingfei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2003年第4期537-546,共10页
An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave... An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave, magnetic and gravity fields show that the crust-mantle structure and its coupling mechanism are the fundamental dynamic causes for the exchange and accumulation of materials and energy in the metallogenic system. Considering the evolution history of the structural setting, the tectono-metallogenic dynamics model of the area can be summarized as follows: (1) occurrence of the greenstone belt during the Archean-Proterozoic-the embryonic form of Au-source system; (2) stable tectonic setting in the Paleozoic-an intermittence in gold mineralization; (3) intensive activation and reformation of the greenstone belt in the Mesozoic-tectono-mineralization and tectono-diagensis; (4) posthumous structural activity in the Cenozoic-destruction of orebodies in the later stage. In the middle and late Indosinian, the Tancheng-Lujiang fault zone cut deeply into the upper mantle so that the ore-bearing fluids migrated to higher layers through the crust-mantle interaction, resulting in alteration and mineralization. 展开更多
关键词 Jiaodong granite-greenstone belt source of ore-forming materials crust-mantle structure tectono-metallogenic model
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Origin and Geological Significance of TTG Gneisses from the Maevatanana Greenstone Belt in North-Central Madagascar,and A Comparison with India 被引量:7
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作者 LI Peng LI Jiankang +2 位作者 LIU Shanbao PEI Rongfu SHI Guanghai 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第3期1003-1024,共22页
The Maevatanana greenstone belt in north-central Madagascar contains widespread exposures of tonalite-trondhjemite-granodiorite (TTG) gneisses, and is important for its concentrations of various metal deposits (e.g... The Maevatanana greenstone belt in north-central Madagascar contains widespread exposures of tonalite-trondhjemite-granodiorite (TTG) gneisses, and is important for its concentrations of various metal deposits (e.g., chromium, niekle, iron, gold). In this paper we report on the petrography, and major and trace element compositions of the TTG gneisses within the Berere Complex of the Maevatanana area, as well as LA-ICP-MS U-Pb ages and Lu-Hf isotopic compositions of zircons from the gneisses. The gneisses consist mainly of granitoid gneiss and biotite (± hornblende) plagiogneiss, and analysis of thin sections provides evidence of crushing, recrystallization, and metasomatism related to dynamic metamorphism. Samples have large variations in their major and trace element contents, with SiO2 = 55.87-68.06 wt%, Al2O3 = 13.9-17.8 wt%, and Na2O/K2O= 0.97-2.13. Geochemically, the granitoid gneisses and biotite plagiogneisses fall on a low-Al trondhjemite to granodiorite trend, while the biotite-hornblende plagiogneisses represent a high-Al tonalite TTG assemblage. Zircon U-Pb dating shows that the Berere Complex TTG gneisses formed at 2.5-2.4 Ga. Most εHf(t) values of zircons from the biotite (q- hornblende) plagiogneisses are positive, while most εHf(t) values from the granitoid gneisses are negative, suggesting a degree of crustal contamination. Two-stage Hf model ages suggest that the age of the protolith of the TTG gneisses was ca. 3.4-2.6 Ga, representing a period of paleocontinent formation in the Mesoarchean. Geothermometries indicate the temperature of metamorphism of the TTG gneisses was 522-612℃. Based on these data, the protolith of the TTG gneisses is inferred to have formed during the development of a Mesoarchean paleocontinent that is now widely exposed as a TTG gneiss belt (mostly lower amphibolite facies) in the Maevatanana area, and which records a geological evolution related to the subduction of an ancient oceanic crust and the collision of microcontinents during the formation of the Rodinia supercontinent. The lithological similarity of Precambrian basement, the close ages of metamorphism within greenstone belts and the comparable distribution of metamorphic grade all show a pronounced Precambrian geology similarity between Madagascar and India, which can provide significative clues in understanding the possible Precambrian Supercontinent tectonics, and also important constraints on the correlation of the two continental fragments. 展开更多
关键词 TTG gneiss PETROLOGY GEOCHRONOLOGY Maevatanana greenstone belt Madagascar INDIA
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“One Belt,One Road”:China and the “Oil Roads” 被引量:1
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作者 Lu Ruquan 《China Oil & Gas》 CAS 2016年第3期7-12,共6页
In the past one and a half years,if one were to have sifted through the keywords of reports,comments,and studies on China’s economy and politics,the'One Belt,One Road'initiative(abbrev.as'OBOR'hereaft... In the past one and a half years,if one were to have sifted through the keywords of reports,comments,and studies on China’s economy and politics,the'One Belt,One Road'initiative(abbrev.as'OBOR'hereafter)must have been one of the most popular words.When 展开更多
关键词 than more CNPC one belt one Road China and the Oil Roads
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Discussion on “One Belt One Road” Construction and International Financial Cooperation 被引量:1
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作者 Qing Miao Christian Asmussen 《Proceedings of Business and Economic Studies》 2020年第3期61-64,共4页
Under the grand economic vision of opening up and cooperation among countries,the world economy is gradually recovering,and economic and trade exchanges between countries are increasing,which is an important sign of s... Under the grand economic vision of opening up and cooperation among countries,the world economy is gradually recovering,and economic and trade exchanges between countries are increasing,which is an important sign of sound economic development.At the same time,we need the joint efforts of all countries to move towards the goal of mutual benefit and common development.We should fully develop one of the"one belt one road"in the economic construction.At the same time,we need to deepen economic cooperation,improve the investment and financing system and credit system,and China International Finance is particularly important.International financial cooperation is one of the difficulties things and“One belt one road”is the same.The financial market's influence on the economic outflow of funds is not to be ignored.Based on this background,one will take the"one belt one road"as the starting point to explore the problems of international financial cooperation. 展开更多
关键词 one belt one road CONSTRUCTION International finance
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Research on Talent Training Model in Higher Vocational Colleges from the Perspective of"One Belt and One Road"Initiative 被引量:1
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作者 Zhang Min Zhang Yuanyuan 《教育研究前沿(中英文版)》 2019年第3期127-131,共5页
The proposal of "One Belt and One Road" development strategy further promotes the internationalization of Higher Vocationalcolleges, puts forward new requirements for personnel training in Higher Vocational ... The proposal of "One Belt and One Road" development strategy further promotes the internationalization of Higher Vocationalcolleges, puts forward new requirements for personnel training in Higher Vocational colleges, and also brings new opportunitiesfor development of Higher Vocational education. Under the background of the "One Belt and One Road" initiative, local highervocational colleges should innovate the talent training mode and accurately orientate the talent training. By sorting out somedeficiencies in the current talent training mode of Higher Vocational Education in China, this paper puts forward the path ofinnovative talent training mode, which can provide reference for higher vocational education to clear its objectives, perfect itsideas and correct its deficiencies, so as to meet the needs of the market for talent training. It is necessary to innovate the concept ofrunning a school, and adopt the school-enterprise cooperation and education model in accordance with the society's demand fortalents, and it is more targeted and effective in the cultivation of talents. Establish the talent training objectives needed to meetlocal development and the implementation of the “Belt and Road” strategy, and build a professional and curriculum system thattakes advantage of regional advantages. 展开更多
关键词 "one belt and one Road" Higher Vocational Colleges Talents Training
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Integrating Green Tourism of Jiangxi Province into “One Belt and One Road” Strategy
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作者 LIU Qiang CAO Chaowen 《Journal of Landscape Research》 2015年第6期99-101,104,共4页
"One Belt and One Road" is a signifi cant move of China to further deepen reform and opening up and improve economic development, and also a key working point of the future national development. This paper, ... "One Belt and One Road" is a signifi cant move of China to further deepen reform and opening up and improve economic development, and also a key working point of the future national development. This paper, on the basis of study on "One Belt and One Road" strategy and current situation of green tourism in Jiangxi, proposed that green tourism in Jiangxi could integrate into the construction of "One Belt and One Road" from the four perspectives of information flow, cultural flow, traffic flow and regional collaboration flow, which contributed to the implementation of national strategies, promoted green tourism development of Jiangxi, and showed the "exceptionally beautiful scenes" of Jiangxi. 展开更多
关键词 one belt and one Road JIANGXI Green tourism
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Reflections on Foreign Language Education Policy Reform in China Under the Background of“One Belt and One Road”Initiative
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作者 XIONG Jinsi JIANG Xiangyong 《Sino-US English Teaching》 2020年第5期149-153,共5页
The initiative of“One Belt and One Road”is an important development strategy under the new normal economic background of China,and foreign economic development relies heavily on foreign language talents of the natio... The initiative of“One Belt and One Road”is an important development strategy under the new normal economic background of China,and foreign economic development relies heavily on foreign language talents of the nation.However,the current foreign language education in China has faced problems from a shortage of compound foreign language talents,inadequacy of foreign languages offered,and imbalanced regional development.Given that the initiative has higher requirements for cultivating foreign language talents,we hold that China’s current foreign language education policy may reform from conducting theoretical studies of foreign language teaching,offering more foreign languages and enhancing professional development of teachers.Conversely,China’s foreign language talents can contribute more to the effective and smooth implementation of the“One Belt and One Road”initiative. 展开更多
关键词 one belt and one Road”initiative foreign language education policy foreign language ability
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A Research on the Construction of International Training Course for Maritime Talents Based on the Initiative of "One Belt and One Road"
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作者 Ding Zi-Hua 《Journal of Shipping and Ocean Engineering》 2018年第2期69-75,共7页
Based on the initiative of "One Belt and One Road" and the demand analysis of the international shipping market for high-quality maritime talents with good skills of communicating ability and international vision, t... Based on the initiative of "One Belt and One Road" and the demand analysis of the international shipping market for high-quality maritime talents with good skills of communicating ability and international vision, this paper analyzes the feasibility, necessity, construction goal, construction principle, construction content, tutorial setting, tutorial structure and tutorial demonstration and explore how" to make China maritime universities' have ability to train the international students in an efficient and orderly manner; by investigating the relevant enterprises and institutions, and presents a plan for the construction of "One Hundred Courses, One Thousand Class-Hours". 展开更多
关键词 The initiative of one belt and one Road" maritime talents one Hundred Courses one Thousand Class-Hours
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The Opportunities, Challenges and Countermeasures of Energy Cooperation between China and Kazakhstan under the Background of "One Belt and One Road"
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作者 KARIPBEK ZHASSULAN 《International English Education Research》 2018年第3期17-19,共3页
Relative to countries such as Russia, the United States, and Europe, China has only recently occupied a place in the energy sector in Kazakhstan. However, after 10 years of hard work, China has come to the fore and th... Relative to countries such as Russia, the United States, and Europe, China has only recently occupied a place in the energy sector in Kazakhstan. However, after 10 years of hard work, China has come to the fore and the fierce energy competition in Kazakhstan has become an important energy trading partner of Central Asian countries. Therefore, we can learn a lot of experience and lessons from our emphasis on cooperation with China's energy trade and research in Central Asian countries. Against the backdrop of fierce international energy competition and the deep implementation of the "One Belt and One Road" initiative, it is like a double-edged sword for energy trade cooperation between China and Central Asian countries, problem. How China seizes opportunities, resolves challenges, and further deepens pragmatic cooperation in the energy sector with Central Asian countries so as to better protect the country' s energy security is a very real issue. 展开更多
关键词 one belt one Road China and Kazakhstan Energy Cooperation
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Driving Force and Popularization Value on Guangzhou Higher Education Internationalization under the Background of National Strategy "One Belt & One Road"
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作者 Li Can 《International English Education Research》 2015年第5期35-38,共4页
With the impetus of the WTO and the further opening of China's international service trade in education, this paper is based on the background of China's national strategy "one belt & one road", analyzing Guangzh... With the impetus of the WTO and the further opening of China's international service trade in education, this paper is based on the background of China's national strategy "one belt & one road", analyzing Guangzhou higher education, its internationalization driving force and popularization value, ranging from the perspectives of higher education resources excess, the domestic university funding cuts, and the transnational education services output in developed countries to alleviate its school funds shortage to further introduction of foreign high-quality educational resources due to not fully meeting the requirements of domestic demand in developing and less developed countries, with expectation to promote the development of education internationalization healthily and orderly. 展开更多
关键词 one belt one Road" National Stratcgy Higher Education Internationalization Driving Force Popularization Value
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Quantitative Analysis of Mainstream Media Coverage of the“One Belt and One Road”Initiative in Central Asian Countries
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作者 Zhang Xin Che Xiangqian 《Cultural and Religious Studies》 2021年第6期267-276,共10页
Five Central Asian countries are active participants in the construction of“One Belt and One Road”.Understanding the acceptance and participation of the“One Belt and One Road”Initiative by Central Asian countries ... Five Central Asian countries are active participants in the construction of“One Belt and One Road”.Understanding the acceptance and participation of the“One Belt and One Road”Initiative by Central Asian countries will help promote the dissemination of some relevant issues,deepen the understanding of“One Belt and One Road”Initiative among the people of the five Central Asian countries,and promote the joint development of“One Belt and One Road”to be deeper and more concrete.This paper takes the official reports related to the“One Belt and One Road”Initiative among the five countries as samples,and on the basis of sorting out the number of reports and analyzing the content of the reports,uses Python language to conduct text mining,and analyzes in detail the reporting tendency and its causes.It is found that due to the different national conditions of Central Asian countries and the development level of their cooperation with China,there are differences in the number and content of the“One Belt and One Road”Initiative reports.Therefore,in addition to strengthening political mutual trust,different communication strategies should be adopted in economic,cultural,and media cooperation to spread the“One Belt and One Road”Initiative to Central Asian countries. 展开更多
关键词 Central Asia one belt and one Road”Initiative disseminate culture
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Training Strategies for Applied German-speaking Talents in the"One Belt One Road"Initiative
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作者 Junliang Ji 《Journal of Contemporary Educational Research》 2021年第7期13-18,共6页
Under the"One Belt One Road”initiative,China and Germany have become closer in cooperation and have made substantial progress in the fields of economy,trade,culture,science,and technology.The close cooperation b... Under the"One Belt One Road”initiative,China and Germany have become closer in cooperation and have made substantial progress in the fields of economy,trade,culture,science,and technology.The close cooperation between China and Germany has raised the demands for diversified German-speaking talents.After years of development and continuous exploration,China's educational institutions with German majors have established a mature talent training model but it is not enough to meet the country's growing demands for applied talents along with the economic development.With the advancement of the national education reform,many majors in various schools are thinking of reform plans suitable for their own development.Although German as a uminor^^language major is not very widely used,it plays an active and effective role in China's trade and cultural exchanges.Hence,there is a need to comprehensively improve students9 overall quality,advocate diversified training methods,adopt German-English bilingualism and professional German teaching methods,increase the cooperation of education between companies and institutions,as well as strive to train more applied German-speaking talents for the country. 展开更多
关键词 one belt one Road Applied German-speaking talents Talent training strategy Compound bilingual Cooperative education
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One Belt,One Law
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作者 Sudeshna Sarkar 《ChinAfrica》 2017年第5期38-39,共2页
THERE was a giant map unfurled beside him and as Lawrence Muiruri Ngugi spoke, he kept on gesturing at it for illumination. The CEO of the Nairobi Center for International Arbitration (NCIA) in Kenya traced the path... THERE was a giant map unfurled beside him and as Lawrence Muiruri Ngugi spoke, he kept on gesturing at it for illumination. The CEO of the Nairobi Center for International Arbitration (NCIA) in Kenya traced the pathways of some of the biggest infrastructure projects in Nairobi: a mammoth oil pipeline, a highway and a standard-gauge railway (SGR). 展开更多
关键词 one belt one Law
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Geochemical Mobility Associated to Gold and Base Metal Occurrences of Mangodara Sector, in Southern Burkina Faso, Banfora Greenstone Belts (West African Craton)
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作者 Bernadin Gnamou Hermann Ilboudo +1 位作者 Wilfried Antoine Bassou Toé Sâga Sawadogo 《Open Journal of Geology》 2023年第10期1024-1053,共30页
In the Mangodara area within the Banfora greenstone belts (Baoulé-Mossi domain of the West African Craton), our study focused on geochemical assessment of the mobility of major and trace elements. Gold and base m... In the Mangodara area within the Banfora greenstone belts (Baoulé-Mossi domain of the West African Craton), our study focused on geochemical assessment of the mobility of major and trace elements. Gold and base metal occurrences are hosted in highly metamorphic felsic (metarhyolite) and intermediate (metadacite and metaandesite) formations. Common mineral assemblages made up of staurolite - kyanite - pyrophyllite are interpreted to represent the metamorphosed equivalent of aluminous hydrothermal alteration. Associated felsic and intermediate volcanic rocks are enriched in Fe<sub>2</sub>O<sub>3</sub>, K<sub>2</sub>O (metaandesite, metarhyolite) and depleted in MgO, Al<sub>2</sub>O<sub>3</sub>, CaO, P<sub>2</sub>O<sub>5</sub>, Na<sub>2</sub>O (metarhyolite) and Fe<sub>2</sub>O<sub>3</sub>, MgO, CaO (metaandesite). Al<sub>2</sub>O<sub>3</sub> depletion in mineralized kyanite-staurotide bearing metarhyolites suggests corroded minerals. Mineralized metarhyolites show enrichment in Au, Ag, Ba, Bi, Cr, Cu, Eu, La, Mo, Ni, Pb, S, Sc, V and depletion in As Sb Co, Sn, Zn while mineralized metaandesites show enrichment in Au, Ag, As, Mo, S, Sb and depletion in Co, Sn, Zn, Bi, Cr, Cu, Eu, Ni, Pb, Sc. Ba, La, V are immobile in metaandesites. Finally, Ag, As, Sn appear as geochemical vectors for gold exploration in the study area since gold mineralization is characterized by Au + Ba + Cu + Eu + La + Mo + Ni + S association in metarhyolites and Au + S + Sb + As + Ag + Bi in metaandesites. 展开更多
关键词 Geochemical Mobility Aluminous Alteration METAMORPHISM GOLD Base Metal Banfora Greenstone belts Mangodara
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Fouimba and Goma Mounts Greenstone Belts Litho-Structural Analysis Related to Côte D’Ivoire Birimian Geodynamic Setting and Implying in West-Africa Craton Gold Deposits
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作者 Marc Ephrem Allialy Brice Roland Kouassi +3 位作者 N’guessan Nestor Houssou Fossou Jean Luc Kouadio Davy Bedel Siogbo Félix Oufouet Konan 《Journal of Geoscience and Environment Protection》 2023年第1期150-168,共19页
Mount Fouimba and Mount Goma (Seguela) greenstone belts petro-structural studies combine remote sensing, geophysics, petrography and structural analysis. In view of establishing mapping details of paleoproterozoic geo... Mount Fouimba and Mount Goma (Seguela) greenstone belts petro-structural studies combine remote sensing, geophysics, petrography and structural analysis. In view of establishing mapping details of paleoproterozoic geological formations, geological setting rocks observed are essentially magmatic formations, such as two-mica granite, granodiorites, and porphyritic basalts;and a few metamorphics which are metatonalite, amphibolites and amphibo-lopyroxenites. Remote sensing, such as Landsat 8 OLI satellite imagery and geophysical data, has been combined to show regional NNE-SW shear zone. Tectonic structures and microstructures have enabled to identify two main deformation phases: D1 phase corresponding to compression, and D2 is a transpression phase. Mechanisms responsible for deformations are respectively flattening and transpression. Geological formations derived from mantle origin but contain crustal components, and their tectonic setting occurred during subduction. 展开更多
关键词 Petro-Structural Mapping Greenstone belt BIRIMIAN Séguéla Côte D’Ivoire
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The Paleoarchean Northern Mundo Novo Greenstone Belt,São Francisco Craton:Geochemistry,U-Pb-Hf-O in zircon and pyriteδ^(34)S-Δ^(33)S-Δ^(36)S signatures
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作者 Guilherme S.Teles Farid Chemale Jr. +1 位作者 Janaína N.Ávila Trevor R.Ireland 《Geoscience Frontiers》 SCIE CAS CSCD 2022年第5期190-206,共17页
Greenstone belts contain several clues about the evolutionary history of primitive Earth.Here,we describe the volcano-sedimentary rock association exposed along the eastern margin of the Gavião Block,named the No... Greenstone belts contain several clues about the evolutionary history of primitive Earth.Here,we describe the volcano-sedimentary rock association exposed along the eastern margin of the Gavião Block,named the Northern Mundo Novo Greenstone Belt(N-MNGB),and present data collected with different techniques,including U–Pb–Hf–O isotopes of zircon and multiple sulfur isotopes(^(32)S,^(33)S,^(34)S,and ^(36)S)of pyrite from this supracrustal sequence.A pillowed metabasalt situated in the upper section of the N-MNGB is 3337±25 Ma old and has zircon with ε_(Hf)(t)=2.47 to1.40,Hf model ages between 3.75 Ga and 3.82 Ga,and δ^(18)O=+3.6‰to+7.3‰.These isotopic data,together with compiled whole-rock trace element data,suggest that the mafic metavolcanic rocks formed in a subduction-related setting,likely a back-arc basin juxtaposed to a continental arc.In this context,the magma interacted with older Eoarchean crustal components from the Gavião Block.Detrital zircons from the overlying quartzites of the Jacobina Group are sourced from Paleoarchean rocks,in accordance with previous studies,yielding a maximum depositional age of 3353±22 Ma.These detrital zircons have ε_(Hf)(t)=5.40 to0.84,Hf model ages between 3.66 Ga and 4.30 Ga,and δ^(18)O=+4.8‰to+6.4‰.The pyrite multiple sulfur isotope investigation of the 3.3 Ga supracrustal rocks from the N-MNGB enabled a further understanding of Paleoarchean sulfur cycling.The samples have diverse isotopic compositions that indicate sulfur sourced from distinct reservoirs.Significantly,they preserve the signal of the anoxic Archean atmosphere,expressed by MIF-S signatures(Δ^(33)S between1.3‰to+1.4‰)and a Δ^(36)S/Δ^(33)S slope of0.81 that is indistinguishable from the so-called Archean array.A BIF sample has a magmatic origin of sulfur,as indicated by the limited Δ^(34)S range(0 to+2‰),Δ^(33)S~0‰,and Δ^(36)S~0‰.A carbonaceous schist shows positive Δ^(34)S(2.1‰–3.5‰)and elevated Δ^(33)S(1.2‰–1.4‰)values,with corresponding negative Δ^(36)S between1.2‰to0.2‰,which resemble the isotopic composition of Archean black shales and suggest a source from the photolytic reduction of elemental sulfur.The pillowed metabasalt displays heterogeneous Δ^(34)S,Δ^(33)S,and Δ^(36)S signatures that reflect assimilation of both magmatic sulfur and photolytic sulfate during hydrothermal seafloor alteration.Lastly,pyrite in a massive sulfide lens is isotopically similar to barite of several Paleoarchean deposits worldwide,which might indicate mass dependent sulfur processing from a global and well-mixed sulfate reservoir at this time. 展开更多
关键词 Northern Mundo Novo Greenstone belt Multiple sulfur isotopes GEOCHRONOLOGY Paleoarchean Gavião Block São Francisco Craton
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Neoarchean granite-greenstone belts and related ore mineralization in the North China Craton:An overview 被引量:13
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作者 Li Tang M.Santosh 《Geoscience Frontiers》 SCIE CAS CSCD 2018年第3期751-768,共18页
Tectonic processes involving amalgamations of microblocks along zones of ocean closure represented by granite-greenstone belts(GGB) were fundamental in building the Earth's early continents. The crustal growth and... Tectonic processes involving amalgamations of microblocks along zones of ocean closure represented by granite-greenstone belts(GGB) were fundamental in building the Earth's early continents. The crustal growth and cratonization of the North China Craton(NCC) are correlated to the amalgamation of microblocks welded by 2.75-2.6 Ga and ~2.5 Ga GGBs. The lithological assemblages in the GGBs are broadly represented by volcano-sedimentary sequences, subduction-collision related granitoids and bimodal volcanic rocks(basalt and dacite) interlayered with minor komatiites and calc-alkalic volcanic rocks(basalt, andesite and felsic rock). The geochemical features of meta-basalts in the major GGBs of the NCC display affinity with N-MORB, E-MORB, OIB and calc-alkaline basalt, suggesting that the microblocks were separated by oceanic realm. The granitoid rocks display arc signature with enrichment of LILE(K,Rb, Sr, Ba) and LREE, and depletion of HFSE(Nb, Ta, Th, U, Ti) and HREE, and fall in the VAG field. The major mineralization includes Neoarchean BIF-type iron and VMS-type Cu-Zb deposits and these,together with the associated supracrustal rocks possibly formed in back-arc basins or arc-related oceanic slab subduction setting with or without input from mantle plumes. The 2.75-2.60 Ga TTG rocks,komatiites, meta-basalts and metasedimentary rocks in the Yanlingguan GGB are correlated to the upwelling mantle plume with eruption close to the continental margin within an ocean basin. The volcanosedimentary rocks and granitoid rocks in the late Neoarchean GGBs display formation ages of 2.60-2.48 Ga, followed by metamorphism at 2.52-2.47 Ga, corresponding to a typical modern-style subduction-collision system operating at the dawn of Proterozoic. The late Neoarchean komatiite(Dongwufenzi GGB), sanukitoid(Dongwufenzi GGB and Western Shandong GGB), BIF(Zunhua GGB) and VMS deposit(Hongtoushan-Qingyuan-Helong GGB) have closer connection to a combined process of oceanic slab subduction and mantle plume. The Neoarchean cratonization of the NCC appears to have involved two stages of tectonic process along the 2.75-2.6 Ga GGB and ~2.5 Ga GGBs, the former involve plume-arc interaction process, and the latter involving oceanic lithospheric subduction, with or without arcplume interaction. 展开更多
关键词 North China CRATON GRANITE GREENSTone belt NEOARCHEAN Plate and plume TECTONICS METALLOGENY
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Metallogenesis of Precambrian gold deposits in the Wutai greenstone belt:Constrains on the tectonic evolution of the North China Craton 被引量:6
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作者 Ju-Quan Zhang Sheng-Rong Li +2 位作者 M.Santosh Jing Lu Chun-Liang Wang 《Geoscience Frontiers》 SCIE CAS CSCD 2018年第2期317-333,共17页
The Wutai greenstone belt in central North China Craton(NCC) hosts a number of Precambrian gold deposits and ore occurrences. Based on the host rock association, these can be divided into Banded Iron Formation(BIF), m... The Wutai greenstone belt in central North China Craton(NCC) hosts a number of Precambrian gold deposits and ore occurrences. Based on the host rock association, these can be divided into Banded Iron Formation(BIF), meta-volcano-sedimentary and meta-conglomerate types. The two former types formed during ~2.5-2.3 Ga and the third one at ~1.85 Ga. The characteristics of these Precambrian gold deposits are broadly similar with those of the orogenic gold deposits. Based on available geochronological data, here we reconstruct the major tectonic events and their relationship with gold mineralization in the Wutai-Hengshan-Fuping region during Neoarchean to Paleoproterozoic as follows.(1)~2.6-2.5 Ga: widespread intrusion of tonalite-trondhjemite-granodiorite(TTG) magmas in the Hengshan terrane and Fuping continental arc, formation of the Wutai volcanic arc in the southern margin of Hengshan terrane with granitoids emplacement, and the Hengshan-Wutai intra-oceanic arc accretion to the Fuping arc at the end of Neoarchean.(2) ~ 2.5-2.3 Ga: the subduction of Hengshan arc from north leading to persistent magmatism and orogenic gold mineralization.(3)~2.2-2.1 Ga:extension leading to the formation of graben structure in the Wutai and Fuping region, deposition of the Hutuo and Wanzi Group sediments, formation of placer gold through erosion of the orogenic gold deposits.(4)~2.2-2.0 Ga: widespread magmatism in the Wutai-Hengshan-Fuping region.(5)~1.95-1.8 Ga: regional metamorphism associated with collision of the Western and Eastern Blocks of the NCC and associated orogenic gold deposits. The multiple subduction-accretion-collision history and subsequent deep erosion has significantly affected most of the Precambrian gold deposits in the Wutai greenstone belt. 展开更多
关键词 Wutai GREENSTone belt OROGENIC gold deposits Geochronology Tectonics North China CRATON
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