检索结果-南通市图书馆

Journal of Earth Science 2024年第1期35卷 16-28页

作者： landry soh tamehe Huan Li Sylvestre Ganno Zuxing Chen Yanick Brice Lemdjou Safiyanu Muhammad Elatikpo School of Geosciences and Info-Physics Central South UniversityChangsha 410083China Department of Earth Sciences University of Yaounde IYaounde 3412Cameroon Institute of Oceanology Chinese Academy of SciencesQingdao 266071China Department of Geology Ahmadu Bello University ZariaZaria 810107Nigeria

The Bipindi iron ore district is located in the central section of the Nyong Complex at the northwestern margin of the Congo Craton in Southwest *** iron district contains numerous iron mineralization hosted by the Mewongo,Bibole,Kouambo,and Zambi banded iron formations(BIFs).These BIFs contain magnetite as the main iron ore mineral associated with pyrite,and gangue minerals are quartz with minor chlorite and *** origin of iron ore from these BIFs was investigated using a combination of in-situ magnetite and whole-rock *** studied BIF ore samples have a narrow range of TFe between 30.90 wt.%and 43.20 wt.%,indicating a low-grade *** geochemical signatures of magnetite such as low contents of base metals(e.g.,Cu,Co,V,and Zn)and low Co/Zn ratios600 and>75,respectively),we suggest that magnetite was derived from a mixture of seawater and~0.1%low-temperature hydrothermal fluids in an oxidizing ***,low-temperature hydrothermal and later metamorphic fluids were necessary for the transformation of the protolith Nyong Complex BIFs to iron ore.

关键词： banded iron formations iron ore geochemistry Congo Craton trace element composition LA-ICP-MS

Depositional age and tectonic environment of the Gouap banded iron formations from the Nyong group,SW Cameroon:Insights from isotopic,geochemical and geochronological studies of drillcore samples

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2021年第2期12卷 549-572页

作者： landry soh tamehe Chongtao Wei Sylvestre Ganno Carlos Alberto Rosiere Jean Paul Nzenti Chesther Gatse Ebotehouna Guanwen Lu Key Laboratory of CBM Resources and Reservoir Formation Process Chinese Ministry of EducationChina University of Mining and TechnologyXuzhouJiangsu221116China Department of Earth Sciences University of Yaounde IP.O.Box 812YaoundeCameroon Department of Geology Universidade Federal de Minas Gerais31270-901Belo HorizonteMinas GeraisBrazil School of Civil and Environmental Engineering University of Science and Technology BeijingBeijing 100083China

The discovery of the Gouap banded iron formations(BIFs)-hosted iron mineralization in the northwestern of the Nyong Group(Ntem Complex)in southwestern Cameroon provides unique insights into the geology of this *** this contribution,we firstly report detailed study of geochemistry,isotopic and geochronology of well preserved samples of the Gouap BIFs collected from diamond *** Gouap BIFs consist mainly of amphibole BIFs and amphibole-pyrite BIFs characterized by dominant Fe_(2)O_(3)+SiO_(2)contents and variable contents of CaO,MgO and SO_(3),consistent with the presence of amphibole,chlorite,epidote and pyrite,formed during amphibolite facies metamorphism and overprinted hydrothermal *** amphibole–pyrite BIFs are typically enriched in trace and rare earth elements(REE)compared to the amphibole BIFs,suggesting the influence of detrital materials as well as secondary hydrothermal *** Post Archean Australian Shale(PAAS)-normalized REE–Y profiles of the Gouap BIFs display positive La,Eu anomalies,weak negative Ce anomalies,indicating a mixture of low-temperature hydrothermal fluids and relatively oxic conditions probably under relative shallow *** present here the first isotopic data of BIFs within the Ntem ***δ^(30)Si_(NBS28)values of the quartz from the Gouap BIFs vary from-1.5‰to-0.3‰and from-0.8‰to-0.9‰for the amphibole BIFs and amphibole–pyrite BIFs,*** quartz hasδ^(18)OV-SMOW values of 6.8‰–9.5‰(amphibole BIFs)and 9.2‰–10.6‰(amphibole–pyrite BIFs).The magnetite from the Gouap BIFs showsδ^(18)O values ranging from-3.5‰to-1.8‰and from-3‰to-1.7‰for the amphibole BIFs and amphibole–pyrite BIFs,***,the pyrite grains in the amphibole–pyrite BIFs displayδ34S values of 1.1‰–1.8‰.All isotopic data of the Gouap BIFs confirm that they might have precipitated from low-temperature hydrothermal fluids with detrital input distant from the volcanic *** to their geochemical and isotop

关键词： Gouap Banded iron formations Isotope geochemistry Zircon geochronology Ryacian period Brasiliano-Congo orogeny

Geochemical constraints on the origin and tectonic setting of the serpentinized peridotites from the Paleoproterozoic Nyong series,Eseka area,SW Cameroon

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2020年第3期39卷 404-422页

作者： Philomene Nga Essomba Tsoungui Sylvestre Ganno Evine Laure Tanko Njiosseu Jean Lavenir Ndema Mbongue Brice Kamguia Woguia landry soh tamehe Jonas Didero Takodjou Wambo Jean Paul Nzenti Department of Earth Sciences University of Yaounde IP.O.Box 3412MessaYaoundeCameroon Department of Earth Sciences University of DschangP.O.Box.67DschangCameroon Key Laboratory of CBM Resources and Reservoir Formation Process Chinese Ministry of EducationChina University of Mining and TechnologyXuzhou 221116JiangsuChina

Serpentinized rocks closely associated with Paleoproterozoic eclogitic metabasites were recently discovered at Eseka area in the northwestern edge of the Congo craton in southern ***,we present new field data,petrography,and first comprehensible wholerock geochemistry data and discuss the protolith and tectonic significance of these serpentinites in the *** studied rock samples are characterized by pseudomorphic textures,including mesh microstructure formed by serpentine intergrowths with cores of olivine,bastites after *** constitutes almost the whole bulk of the rocks and is associated(to the less amount)with tremolite,talc,spinel,and ***-rock chemistry of the Eseka serpentinites led to the distinction of two *** 1 has high MgO(>40 wt%)content and high Mg#values(88.80)whereas Type 2 serpentinite samples display relatively low MgO concentration and Mg#values(50 ppm).This similarity,associated with the high Cr contents,spinel-peridotite protolith compositions and Mg/Si and Al/Si ratios imply that the studied serpentinites were formed in a subductionrelated *** U-shaped chondrite normalizedREE patterns of serpentinized peridotites,coupled with similar enrichments in LREE and HFSE,suggest the refertilized nature due to melt/rock interaction prior to *** on the results,we suggest that the Eseka serpentinized peridotites are mantle residues that suffered a high degree of partial melting in a subductionrelated environment,especially in Supra Subduction Zone *** new findings suggest that the Nyong series in Cameroon rep

关键词： Serpentinites Mantle peridotites Melt/rock interaction Paleoproterozoic suture zone Eseka area Nyong series Congo/Sao Francisco cratons

喀麦隆西南部Mamelles条带状铁建造元素地球化学特征

在线全文

学校读者我要写书评

暂无评论

海洋科学 2024年第7期48卷 47-56页

作者： soh tamehe landry GANNO Sylvestre 陈祖兴 ROSIÈRE Carlos Alberto 中国有色桂林矿产地质研究院有限公司广西桂林541004 Department of Earth Sciences University of Yaounde I812 YaoundeCameroon 中国科学院海洋研究所山东青岛266071 Department of Geology Universidade Federal de Minas Gerais31270-901 Belo HorizonteMinas GeraisBrazil

Mamelles铁矿床位于喀麦隆南部刚果克拉通西北缘,距离克里比地区东南方向约20km。该矿床由大规模、高品位磁铁矿矿体组成,赋存于Nyong杂岩体的条带状铁建造(BIF)中。该矿床中的BIF与角闪岩和片麻岩相伴生。在详细的野外调查基础上,我们... 详细信息

Mamelles铁矿床位于喀麦隆南部刚果克拉通西北缘,距离克里比地区东南方向约20km。该矿床由大规模、高品位磁铁矿矿体组成,赋存于Nyong杂岩体的条带状铁建造(BIF)中。该矿床中的BIF与角闪岩和片麻岩相伴生。在详细的野外调查基础上,我们获取了BIF的全岩地球化学数据,并用以约束它们的物质来源和沉积环境。弱正铕(Eu)异常(δEu=2.14~3.55)表明高温热液流体对MamellesBIF的贡献是通过海底火山岩蚀变作用的方式,并有少量碎屑物质输入。正铈(Ce)异常的缺失表明,这些BIF可能沉积在缺氧的深海环境中,如火山弧或弧后盆地深水区。

关键词：刚果克拉通喀麦隆 Mamelles铁矿条带状铁建造地球化学