检索结果-南通市图书馆

Geochemical evaluation of mineralization potential of the Somie-Ntem area within the Tikar plain,Cameroon:implication on petrogenesis

引用

Acta Geochimica 2022年第5期41卷 861-886页

作者： Mero Yannah Yaya Fodoue Maurice Kwekam Benoit Joseph Mbassa Juliana Amboh Tifang armand dongmo kagou Samuel Ndonwi Ayonghe Institute of Geological and Mining Research YaoundeCameroon Department of Earth Sciences University of DschangDschangCameroon Central Unit for Internal Control and Evaluation University of BueaBueaCameroon

Somie-Ntem area of the Tikar plain belongs to the western Cameroon *** lithology of the plain has been characterized,and the mineral potential is still unclear despite previous reports on Sn deposit within one of the magmatic *** results show two groups of granitic rocks displaying oxidized and reduced character;(1)mesocratic(oxidized)granites including biotitebearing,hornblende-biotite-bearing,hornblende-epidotebearing and pyroxene-bearing;(2)leucogranites(reduced)that are generally amphibole-pyroxene *** granitoids are hosted by gneisses and metasedimentary rocks partially covered by *** element composition shows high-K calc-alkaline to shoshonite affinity,metaluminous to weakly peraluminous I-type *** granites show moderately negative Eu anomaly,depleted in Nb,P,Ti,and are related to syn-collisional *** are post-orogenic with strong negative Eu anomaly,depleted in Ba and Sr and enriched in Hf,Nb and *** are fertile in Sn and Zn,enriched through postmagmatic metasomatism and ***–Cu–Ni–V mineralization occurs in hornblende-bearing gneisses and their enrichment suggests a possible Ni–Cutype PGEs mineralization in this ***,their trace element shows high Ni/Cu,very low Rb/Sr,low LILE and LREE which indicates mantle fractionation at *** absence of olivine and pyroxene,and increased SiO_(2)and Al_(2)O_(3)in the Cr–Cu–Ni–V-bearing rocks show that the parent magma experienced fractional crystallization and crustal contamination during ***,the high Zr/Rb and K/Rb ratios show that hydrothermal activity was not intense to enhance mineralization in the *** in the direction of stress during shear deformation inhibited an effective hydrothermal activity and ore deposition in the region.

关键词： Geochemistry Mineralization Somie-Ntem Tikar plain Cameroon

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

Interpretation of Geological and Gravity Data from the Bamiléké Plateau (West-Cameroon): Implication for the Understanding of Its Underground Lithotectonic Geometry

引用

Journal of Geoscience and Environment Protection 2024年第9期12卷 283-314页

作者： Louis Christian Kamgang Chendjou Jean Victor Kenfack Jules Tcheumenak Kouémo Fidèle Koumetio armand kagou dongmo Department of Earth Sciences Faculty of Science University of Dschang Dschang Cameroon Department of Earth Sciences Faculty of Sciences University of Douala Douala Cameroon Department of Physics Faculty of Sciences University of Dschang Dschang Cameroon

The Bamiléké Plateau represents a key domain in the understanding of the geodynamics associated with the central Cameroon shear. The study aimed to highlight the subsurface architecture of the plateaus basement setting with focus on high potential areas for hydrogeological and mining development projects. To this end, geological field observations were carried out. Since the structures sought were near-surface, a separation approach based on the upward continuation method was applied to the Bouguer anomaly grid. A set of processing techniques, including vertical derivative or DZ, analytical signal or SA and categorization of gravity signatures, was applied to generate the residual map. The synthesis geological model, obtained from analysis and interpretation of the various transformed maps and 2.5D modeling of two gravity profiles P1 and P2 highlights the following features: 1) intrusions of steep-sided granitic batholiths from Dschang to Bandjoun (profile P1), increasing in width from NW (Dschang) to SE (Bandjoun);2) larger volume batholiths with moderate sides located at Bafang and Bangangté (profile P1). These plutonic massifs were weakened by brittle deformation, which favored the emplacement of phonolite or anorthosite dykes within them. The emplacement of these dykes was accompanied by compressional faults with high dip between Dschang and Bandjoun and extensional faults with medium dip between Bafang and Bangangté. These fault zones (trending N85E to N95E) are ideal for hydrogeological investigations in a basement setting, as well as a series of dyke networks that could potentially be preferred zones for the circulation and accumulation of useful substances. The resulting geological sections P1 and P2 highlight the influence of granitic intrusions in the geological system of the study area, as well as the structural control associated with the various dyke intrusions. All the models obtained can serve as fundamental references for hydrogeological and mining e

关键词： Bamiléké Plateau Gravity Measurement Gravity Anomalies Lineaments

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

Typology of Natural Hazards and Assessment of Associated Risks in the Mount Bambouto Caldera(Cameroon Line,West Cameroon)

引用

Acta Geologica Sinica(English Edition) 2009年第5期83卷 1008-1016页

作者： Ghislain T.ZANGMO armand D.kagou David G.NKOUATHIO Pierre WANDJI Department of Earth Science Faculty of ScienceUniversity of DschangCameroon Laboratory of Geology High Teacher Training SchoolUniversity of Yaounde ICameroon

Mount Bambouto is a polygenic stratovolcano of the Cameroon Volcanic Line, built between 21 Ma and 4.5 Ma. It is situated approximately 200 km NE of Mount Cameroon, between 09° 55＇ and 10°15＇ longitude east and, 05°25＇ and 05°50＇ latitude north. The volcano covers an area of 500 km^2 and culminates at 2740 m at Meletan dome and bears a collapsed caldera at the summit （13 × 8 km）. Mount Bambouto is characterized by several natural hazards of different origins： meteorological, such as landslides and rock falls; anthropogenic, such as bushfires, tribal wars and deforestation; and volcanological, such as volcanic eruption. The thematic map shows that 55-60% of the caldera has high probability of occurrence of mass movement. The caldera has a high population density （3000 inhabitants）, which increases the level of risk, evaluated at approximately $US3.8 million for patrimony, 3000 civilian deaths and destruction of biodiversity.

关键词： caldera hazard risk assessment Mount Bambouto Cameroon Line

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

Study of Multi-Origin Hazards and Assessment of Associated Risks in the Lefo Caldera (Bamenda Volcano, Cameroon Line)

引用

International Journal of Geosciences 2014年第11期5卷 1300-1314页

作者： Zangmo Tefogoum Ghislain Nkouathio David Guimolaire kagou dongmo armand Gountie Dedzo Merlin Kamgang Pierre Department of Earth Sciences Faculty of Sciences University of Maroua Maroua Cameroon Department of Earth Sciences Faculty of Sciences University of Dschang Dschang Cameroon Department of Life and Earth Science High Teacher Training College University of Maroua Maroua Cameroon Department of Earth Sciences Faculty of Science University of Yaounde 1 Yaounde Cameroon

The Bamenda Volcano (BV) (2621 m) is a stratovolcano situated in the Cameroon Line (CL). BV includes Mount Lefo (2534 m) which is situated on its southern slopes and contains one elliptical caldera (3 × 4 km). This caldera is propitious to farming and breeding activity. Despite these profitable assets, Lefo caldera (LC) is an amphitheater of the occurrence of multi-origin hazards that have direct or indirect impacts on the biodiversity and human patrimony. The most present hazards are those of meteorological origin. Numerous combined factors (steepest slopes, heavy rainfalls, weathered state of volcanic products…) rule these hazards. These factors gave rise to the occurrence of landslides, gullies erosion and rock falls which occur precisely on caldera northern and eastern rims. Hazards of anthropogenic origin are based on the destruction of the vegetation cover by the population for dealing, firewood and building issues. Moreover, during the breeding activity, the cattle covers the caldera throughout the day;this unevens the topography and destroys the meadow. Hazards of volcanological origin are not yet occurring in LC;but the recent Lake Monoun (1984) and Nyos (1986) CO2 eruptions, mount Cameroon eruptions (1999 and 2000) and mount Oku Lake event (2011) which are close to the BV and, the age of 0 Myr of basalt, constitutes a subject of controversy toward the reactivation of the Cameroonian hotspot faults. The assessment of risks in LC was based on the average income of breeding activity and house investment. The economy of LC is valued at about US$527472.527. The level of such risk will be important in case of loss of human beings and the destruction of geomorphosites’ values. In order to reduce the level of looses in this zone, hazard and risks maps are provided in this paper as well as some recommendations.

关键词： Hazards Risk Anthropogenic Activities Lefo Caldera

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

Typology of Natural Hazards and Assessment of Associated Risks in the Mount Bambouto Caldera(Cameroon Line,West-Cameroun)

引用

地学前缘 2009年第S1期16卷 66-66页

作者： Zangmo Tefogoum Ghislain kagou dongmo armand Nkouathio David Guimolaire Wandji Pierre Department of Earth Science University of Dschang Laboratory of Geology ENSUniversity of Yaounde IB.P.47 Yaounde

Mount Bambouto is a polygenic stratovolcano of the Cameroon Volcanic Line,built between 21 Ma and 4.5 Ma(Nkouathio et al.,2008).It is situated at about 200 km NE of mount Cameroon,at 09°55′and 10°15′East and,05°25′and 05°50′*** volcano covers an area of 500 Km^2 and culminates at 2740 m at Meletan hill and bears a collapsed elliptical caldera at the summit(13×8 km).Mount

关键词： Cameroon Line Mount Bambouto caldera hazards risks

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

Geochemical Signatures of Séguéla Peridotites in the West African Craton

引用

Journal of Geoscience and Environment Protection 2022年第12期10卷 100-116页

作者： Allialy Marc Ephrem Dicko kagou Houssou N’guessan Nestor Kouamelan Alain Nicaise Coulibaly Yacouba Laboratory of Geology Mineral and Energy Resources (LGRME) Faculty of Earth Science and Mineral Resources Félix Houphoue&#235 t Boigny University Abidjan C&#244 te d’Ivoire

The present study deals with peridotites found in the paleo-proterozoic domain of the Leo Man Shield, Séguéla region, west-central of Côte d’Ivoire. Results show that Séguéla peridotites are composed of lherzolites, dunites and harzburgites. However, iherzolites are the most abundant. The phenocrysts in these rocks are olivine most often serpentinised, and pyroxenes, represented by diopside and enstatite. Amphiboles are divided into two groups: magmatic amphiboles and those from the destabilization of clinopyroxene. Spinels have CrO3 content which varies between 28% and 37%, Al2O3 between 33% - 41% and MgO is equal to 18%;they are poor in TiO2 and do not contain zinc oxide. Séguéla peridotites are characterised by a negative anomaly in Nb-Ta, associated with an enrichment of lithophilic elements and light rare earth elements with a fractionation rate (La/Yb) which varies between 46.22 and 150.72 and heavy rare earth elements, and HFSE depletion, which may suggest that were formed in an art context, that is, a mantle enriched by fluids from a subduction zone. However, another hypothesis could be considered, that of the interaction between the mantle and magmas in a subduction zone context.

关键词： Geochemestry Peridotites Lherzolite West African Craton Séguéla Côte d’Ivoire

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

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

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：