Preserved ancient oceanic lithosphere within the Buem structural unit at the eastern margin of the west African craton

Lithos ◽  
2022 ◽  
pp. 106585
Author(s):  
Daniel Kwayisi ◽  
Marlina Elburg ◽  
Jeremie Lehmann
Keyword(s):  
Structural Unit ◽  
Oceanic Lithosphere ◽  
West African ◽  
The West ◽  
West African Craton ◽  
Eastern Margin

Les anomalies gravimétriques de la boucle du Niger. Leur signification dans le cadre de l'orogenèse panafricaine

1980 ◽  
Vol 17 (11) ◽  
pp. 1538-1545 ◽  
Author(s):  
A. Lesquer ◽  
A. Moussine-Pouchkine
Keyword(s):  
Bouguer Anomaly ◽  
Thick Layer ◽  
Gravity Anomalies ◽  
West African ◽  
Geological Time ◽  
The West ◽  
West African Craton ◽  
Long Wavelength ◽  
Eastern Margin ◽  
Intrusive Rocks

The eastern margin of the west African craton along the Niger River in Mali is characterized by long wavelength, positive gravity anomalies. One of these anomalies, the Gourma anomaly, corresponds to the Gourma basin, a gulf of northeast–southwest subsidence, perpendicular to the Panafrican belt which presents all the characteristics of an aulacogen. The gravity anomalies show, under the upper Precambrian sediments, a thick layer of dense rocks, probably associated with pre-Panafrican rifting that occurred ca. 800–850 Ma ago along the eastern margin of the West African craton with a triple point in Mali.The extension of this structure inferred from Bouguer anomaly maps can be traced southward along more than 200 km north-northeast–south-southwest (Mopti anomaly). The gravity pattern shows that the shape of the subsiding basins is linked to preexisting fractures which have been rejuvenated during geological time. The subsidence, in part due to the weight of effusive and intrusive rocks, probably caused a downward deflection of the crust, explaining the negative anomalies that edge the Gourma and Mopti positive anomalies.

The magmatic evolution at the Moroccan outboard of the West African craton between the Late Neoproterozoic and the Early Palaeozoic

2008 ◽  
Vol 297 (1) ◽  
pp. 329-343 ◽  
Author(s):  
H. Ezzouhairi ◽  
M. L. Ribeiro ◽  
N. Ait Ayad ◽  
M. E. Moreira ◽  
A. Charif ◽  
...  
Keyword(s):  
West African ◽  
Magmatic Evolution ◽  
The West ◽  
West African Craton ◽  
Late Neoproterozoic ◽  
Early Palaeozoic

Paleomagnetism of the ~860 Ma Manso dyke swarm, West Africa: implications for the assembly of Rodinia

2021 ◽  
Author(s):  
Paul Yves Jean Antonio ◽  
Lenka Baratoux ◽  
Ricardo Ivan Ferreira Trindade ◽  
Sonia Rousse ◽  
Anani Ayite ◽  
...  
Keyword(s):  
West Africa ◽  
West African ◽  
Dyke Swarm ◽  
Jigsaw Puzzle ◽  
The West ◽  
West African Craton ◽  
Contact Test ◽  
Fine Grained ◽  
Paleomagnetic Pole ◽  
Coarse To Fine

<p>The West African Craton (WAC) is one of the major cratons in the Rodinia jigsaw puzzle (~1000–750 Ma). In the Rodinian models, the position of West Africa is mainly constrained by the assumption that it had been a partner of Amazonia since the Paleoproterozoic. Unfortunately, no paleomagnetic data are available for these cratons when the Rodina supercontinent is considered tectonically stable (~1000-750 Ma). Thus, every new reliable paleomagnetic pole for the West African Craton during the Neoproterozoic times is of paramount importance to constrain its position and testing the Rodinia models. In this study we present a combined paleomagnetic and geochronological investigation for the Manso dyke swarm in the Leo-Man Shield, southern West Africa (Ghana). The ~860 Ma emplacement age for the NNW-trending Manso dykes is thus well-constrained by two new U-Pb apatite ages of 857.2 ± 8.5 Ma and 855 ± 16 Ma, in agreement with baddeleyite data. Remanence of these coarse-to-fine grained dolerite dykes is carried by stable single to pseudo-single domain (SD-PSD) magnetite. A positive baked-contact test, associated to a positive reversal test (Class-C), support the primary remanence obtained for these dykes (13 sites). Moreover, our new paleomagnetic dataset satisfy all the seven R-criteria (R=7). The ~860 Ma Manso pole can thus be considered as the first key Tonian paleomagnetic pole for West Africa. We propose that the West Africa-Baltica-Amazonia-Congo-São Francisco were associated in a long-lived WABAMGO juxtaposition (~1100–800 Ma).</p><p><strong>Keywords:</strong> West Africa, Neoproterozoic, Tonian, Rodinia, paleomagnetism.</p><p> </p>

Early Neoproterozoic rift-related magmatism in the Anti-Atlas margin of the West African craton, Morocco

2014 ◽  
Vol 255 ◽  
pp. 433-442 ◽  
Author(s):  
J. Javier Álvaro ◽  
André Pouclet ◽  
Hassan Ezzouhairi ◽  
Abderrahmane Soulaimani ◽  
El Hafid Bouougri ◽  
...  
Keyword(s):  
West African ◽  
The West ◽  
West African Craton ◽  
Early Neoproterozoic

scholarly journals Supplemental Material: Reorienting the West African craton in Paleoproterozoic–Mesoproterozoic supercontinent Nuna

2021 ◽  
Author(s):  
Zheng Gong ◽  
et al.
Keyword(s):  
West African ◽  
The West ◽  
West African Craton

Detailed geochronological, paleomagnetic, and rock magnetic results.

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