Structural features of South-Adamawa (Cameroon) inferred from magnetic anomalies: Hydrogeological implications

Noutchogwe, Constant Tatchum; Koumetio, Fidèle; Manguelle-Dicoum, Eliézer

doi:10.1016/j.crte.2010.03.004

Cited by 14 publications

(6 citation statements)

References 20 publications

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“…Consequently, the late dextral shear movement [dated at 552 Ma (EMP dating on monazite [94])], along the Central Cameroon Shear Zone, may have served as a path for the dyke's magma during their ascent towards the surface. This idea is consistent with the layout of the pan-African fracture network and the hypothesis of a reactivation or re-play of the Pan-African structures associated with the dyke swarms of the Pan-African North Equatorial Fold Belt [95]. The geochronological data that may clarify the emplacement ages of these dykes are not yet been established.…”

Section: Comparison With Other Dykes From the Central African Fold Belt In Cameroonsupporting

confidence: 74%

Petrochemical constrains on the origin and tectonic setting of mafic to intermediate dykes from Tikar plain, Central Cameroon Shear Zone

et al. 2021

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The Tikar plain is located on the Cameroon Central Shear Zone. It is also part of the North Equatorial Pan-African Belt. It is formed of granitoids intruded in places by mafic and intermediate dykes. The mafic dykes are essentially banded gabbros composed of plagioclases, pyroxenes, amphiboles, biotites and opaques. Their textures range from porphyroblastic to porphyritic. The intermediate dykes are monzonites and monzodiorites and are characterized, respectively, by cataclastic and mylonitic textures. The minerals identified are amphiboles, potassium feldspar, pyroxenes, epidotes, sphenes and opaques. Seritization reaction is mostly present on the mafic and intermediate dykes, while chloritization is much more pronounced on the intermediate dykes. The Tikar plain dykes are high-k calc-alkaline to shoshonitic. They are characterized by low to moderate SiO2 content (42.08–61.96 wt%), low to high TiO2 (0.47–2 wt%) and low Ni (1.48–99.18 ppm) contents. The mafic dykes show fractional trends with negative anomalies of Zr, U and P and positive Rb, Ba, Ta, Pb and Sr in multi-element diagrams, while the intermediate dykes present negative anomalies of Nb, Ta, Zr, Sr P and Ti and relative positive anomalies of Rb, Ba and Pb. The rare-earth elements (REE) patterns show positive Eu anomalies for the mafic dykes and negative anomalies for the intermediate dykes. The REE spectrum of all the dykes shows enrichment in LREE with relatively flat HREE, which can indicate arc magmatism. In the Zr–Ti/100–Sr/2 diagram, the mafic dykes plot in the island arc tholeiite and calc-alkaline basalt fields. The Th, Nb and LREE concentrations indicate that the subducted lithosphere with crustal component contributed to generation of the intermediate dykes of the Tikar plain. The geochemical characteristics of the mafic to intermediate dykes suggest their derivation from a various degree of partial melting in the garnet spinel facies, probably between depths of 80 and 100 km. The collision between the Central African Fold Belt and the northern edge of the Congo craton resulting in crustal thickening, sub-crustal lithospheric delamination and upwelling of the asthenosphere may have been the principal process in the generation of the intermediate dykes in the Tikar plain. The magma for the mafic and intermediate dyke would have migrated through the faults network of the Central Cameroon Shear Zone before crystallizing in the granito-gneissic basement rocks.

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Section: Comparison With Other Dykes From the Central African Fold Belt In Cameroonsupporting

confidence: 74%

Petrochemical constrains on the origin and tectonic setting of mafic to intermediate dykes from Tikar plain, Central Cameroon Shear Zone

et al. 2021

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“…In fact, both areas are located within the Central Africa Pan-African Shear Zone, and it has been demonstrated that the activity of such a large-scale shear zone is capable to originate similar structural associations (Moreau et al, 1987). Therefore, the late dextral shearing movement dated at 552 Ma (EMP dating on monazite; Tchaptchet Tchato et al, 2009) along the CCSZ, which served as pathways for the ascent into the surface of tholeiitic magma, is consistent with the geometric arrangement of this Pan-African fracture network and the hypothesis of a reactivation of Pan-African structures that originated from the Cretaceous sedimentary basins with which the dyke swarms are associated (Noutchogwe et al, 2010). These within-plate basalts derived from lithospheric extension (Kuepouo et al, 2006;Maluski et al, 1995;Youbi et al, 2003), which is consistent with the geophysical data of Tokam et al (2010), in which the crustal thickness in Cameroon is significantly thinned under Cretaceous sedimentary basins.…”

Section: Comparison With Other Regional Igneous Eventssupporting

confidence: 73%

Geology, mineralogy and geochemistry of the Kekem dyke swarm (Western Cameroon): Insights into Paleozoic–Mesozoic magmatism and geodynamic implications

Tchaptchet

Wambo

Kouamo

et al. 2017

Comptes Rendus. Géoscience

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The broadly N70°–90°E-trending dykes swarm at Kekem cut across the Paleoproterozoic-to-Achean terranes of West Cameroon remobilized during the Pan-African orogeny. They are picrite basalts and basalts with tholeiitic/transitional affinity, as shown by mineralogical and geochemical data, with variable major and trace element contents, MgO ranges from 7.3 to 12.4 wt.%, Cr from 190 to 411 ppm, Ni from 15 to 234 ppm. All the dykes are light REE enriched with LaN/YbN values of 5.3–8.1, suggesting a co-magmatic origin. They originated from a 2.8% partial melting of a spinel-mantle source with no or little crustal input. The geochemical features of Kekem dykes are similar to those of Paleozoic and Mesozoic dykes recorded in North and Central Africa, suggesting multiple reactivations of pre-existing fractures that resulted in the fragmentation of western Gondwana and the opening of Central and South Atlantic Ocean

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“…In this study, in order to calculate the upward continuation, we use the Fourpot program [42] . The maximum value of h must be equal to the optimum upward continuation height h 0 of the gravimetric field [17,18] .…”

Section: Determination Of the Upward Continued Field At Different Hei...mentioning

confidence: 99%

“…This residual local scale component often delineates mineral and hydrocarbon prospects at relatively shallower depths [14,15] . The method of Zeng et al [16] is used to separate the regional anomaly from the Bouguer anomaly to obtain the residual anomaly as recently developed by many authors [17][18][19] . The residual anomaly map shows that the Babouri-Figuil Basin is characterized by low-value anomalies while the Mayo Oulo-Lere Basin is situated on high-value anomalies.…”

Section: Introductionmentioning

confidence: 99%

Crustal Structures Inferred from Combined Terrestrial and Earth Gravity Data beneath the Babouri-Figuil and Mayo Oulo-Lere Basins, North Cameroon and South Chad

Saidou,

Bouba,

Oyoa

et al. 2024

eps

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In this work, the study of the crustal structure of the Babouri-Figuil and Mayo Oulo-Lere sedimentary basins was carried out through the interpretation of gravity data. These data were obtained by combining the terrestrial gravity data obtained from the Earth Gravitational Model 2008. The analysis of the terrestrial Bouguer anomaly maps reveals both negative and positive anomalies. Negative anomalies, i.e., low-density signatures, are interpreted as specific rock types on the basis of the geological knowledge of the region while the positive anomalies are attributed to basaltic rocks underlying a generally granitic environment. The empirical method was used to distinguish anomalies due to deep structures from those due to near-surface structures. This method testifies that the residual map of degree 4 is appropriate. Six profiles are drawn on this residual Bouguer anomaly map and are interpreted using spectral analysis and 2D modeling methods. The results indicate that the mean depths of mass sources at the near-surface of the Babouri-Figuil and Mayo Oulo-Lere sedimentary basins are located at 1.50 km and 1.55 km, respectively. Moreover, the Babouri-Figuil Basin is constituted of two formations while the Mayo Oulo-Lere Basin exhibits three distinct formations. These models also help clarify the geological structure of the study area as well as the thicknesses of the sedimentary basins.

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Structural features of South-Adamawa (Cameroon) inferred from magnetic anomalies: Hydrogeological implications

Cited by 14 publications

References 20 publications

Petrochemical constrains on the origin and tectonic setting of mafic to intermediate dykes from Tikar plain, Central Cameroon Shear Zone

Petrochemical constrains on the origin and tectonic setting of mafic to intermediate dykes from Tikar plain, Central Cameroon Shear Zone

Geology, mineralogy and geochemistry of the Kekem dyke swarm (Western Cameroon): Insights into Paleozoic–Mesozoic magmatism and geodynamic implications

Crustal Structures Inferred from Combined Terrestrial and Earth Gravity Data beneath the Babouri-Figuil and Mayo Oulo-Lere Basins, North Cameroon and South Chad

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