U-Pb dating and isotopic signature of the alkaline ring complexes of Bou Naga (Mauritania): its bearing on late proterozoic plate tectonics around the West African craton

Blanc, Ana Crespo; Bernard-Griffiths, J.; Caby, Renaud; Caruba, C.; Caruba, Raoul; Dars, René; Fourcade, Serge; Peucat, Jean-Jacques

doi:10.1016/0899-5362(92)90034-a

Cited by 17 publications

(8 citation statements)

References 18 publications

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“…The oldest rifting is evidenced in the westernmost portions of the West African craton by the intrusion at 687 ± 5 Ma of alkaline granites and syenites exposed in the Bou Naga window (Blanc et al, 1992). The calc-alkaline plutons from arc-type assemblage of the western domain intruded 670 Ma ago in a continental arc setting; it represents the westernmost terrane exposed in the Central Mauritanides.…”

Section: Towards a Geodynamic Modelmentioning

confidence: 99%

Neoproterozoic and Hercynian metamorphic events in the Central Mauritanides: Implications for the geodynamic evolution of West Africa

Caby¹,

Kiénast²

2009

Journal of African Earth Sciences

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Section: Towards a Geodynamic Modelmentioning

confidence: 99%

Neoproterozoic and Hercynian metamorphic events in the Central Mauritanides: Implications for the geodynamic evolution of West Africa

Caby¹,

Kiénast²

2009

Journal of African Earth Sciences

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“…To characterize the sedimentary sources of the Cretaceous sediments deposited in the eastern Central Atlantic Ocean, we use a compilation of 794 published Sr and Nd isotope values measured on sedimentary and magmatic rocks of the WAC (supporting information Table S1, Ajaji et al, ; Ali et al, ; Allègre et al, ; Asiedu et al, ; Azzouni‐Sekkal et al, ; Bea et al, ; Blanc et al, ; Boher et al, ; Deckart et al, ; Dia et al, ; D'Lemos et al, ; Dupuy et al, ; El Baghdadi et al, ; Ennih & Liégeois, ; Errami et al, ; Essaifi et al, ; Fullgraf et al, ; Gasquet et al, ; Jakubowicz et al, ; Key et al, ; Kouamelan et al, ; Le Goff et al, ; Meyer et al, ; Montero et al, ; Othman et al, ; Pawlig et al, ; Peucat et al, ; Potrel et al, ; Roddaz et al, ; Samson et al, ; Schaltegger et al, ; Schoepfer et al, ; Soumaila et al, ; Mohammed et al, 2015; Tahiri et al, ; Taylor et al, ; Thomas et al, ; Toummite et al, ; Verati et al, ). This database allows a comprehensive picture of differences in the isotopic composition of the main geological units present in the WAC (Figure c).…”

Section: Geological Setting and Sediment Sourcesmentioning

confidence: 99%

Geochemical Evidence for Large‐Scale Drainage Reorganization in Northwest Africa During the Cretaceous

Mourlot

Roddaz

Dera

et al. 2018

Geochem Geophys Geosyst

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West African drainage reorganization during Cretaceous opening of the Atlantic Ocean is deciphered here from geochemical provenance studies of Central Atlantic sediments. Changes in the geochemical signature of marine sediments are reflected in major and trace element concentrations and strontium‐neodymium radiogenic isotopic compositions of Cretaceous sedimentary rocks from eight Deep Sea Drilling Project (DSDP) sites and one exploration well. Homogeneous major and trace element compositions over time indicate sources with average upper (continental) crust signatures. However, detailed information on the ages of these sources is revealed by neodymium isotopes (expressed as ɛNd). The ɛNd(0) values from the DSDP sites show a three‐step decrease during the Late Cretaceous: (1) the Albian‐Middle Cenomanian ɛNd(0) values are heterogeneous (–5.5 to −14.9) reflecting the existence of at least three subdrainage basins with distinct sedimentary sources (Hercynian/Paleozoic, Precambrian, and mixed Precambrian/Paleozoic); (2) during the Late Cenomanian‐Turonian interval, ɛNd(0) values become homogeneous in the deepwater basin (–10.3 to −12.4), showing a negative shift of 2 epsilon units interpreted as an increasing contribution of Precambrian inputs; (3) this negative shift continues in the Campanian‐Maastrichtian (ɛNd(0) = −15), indicating that Precambrian sources became dominant. These provenance changes are hypothesized to be related to the opening of the South and Equatorial Atlantic Ocean, coincident with tectonic uplift of the continental margin triggered by Africa‐Europe convergence. Finally, the difference between ɛNd(0)values of Cretaceous sediments from the Senegal continental shelf and from the deepwater basins suggests that ocean currents prevented detrital material from the Mauritanides reaching deepwater areas.

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“…In this study, we used a total of 241 samples analysed for Nd isotopes, 62 from the Cambro‐Ordovician rocks of Central Iberia (Montero et al. , 2007; Talavera, 2009), 83 from the Anti‐Atlas (Blanc et al. , 1992; Barbey et al.…”

Section: Sources Of Datamentioning

confidence: 99%

The palaeogeographic position of Central Iberia in Gondwana during the Ordovician: evidence from zircon chronology and Nd isotopes

et al. 2010

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Terra Nova, 22, 341–346, 2010 Abstract The abnormally elevated abundance of inherited zircon (locally up to 80–90% of zircon grains contain pre‐magmatic cores) in the Cambro‐Ordovician magmatic rocks of Central Iberia made possible an estimation of the distribution of ages of their source rocks. The comparison of inherited U–Pb ages and whole‐rock Nd model ages with those of three main North African Neoproterozoic terranes reveals that the Iberian magmas can only have been generated from a crust similar to that of the East African Orogen west of the Arabian–Nubian Shield. Such crust is currently found in the three Precambrian inliers of the Western Desert of Egypt east of the Archaean terranes of Gebel Kamel. Palaeontological evidence also indicates that the Ordovician fauna of Central Iberia is similar to that of the region between eastern Algeria and Arabia; therefore, we conclude that during the Ordovician Iberia was not attached to north‐west Africa near Morocco, as is usually assumed, but instead to the East African Orogen in northern Egypt.

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U-Pb dating and isotopic signature of the alkaline ring complexes of Bou Naga (Mauritania): its bearing on late proterozoic plate tectonics around the West African craton

Cited by 17 publications

References 18 publications

Neoproterozoic and Hercynian metamorphic events in the Central Mauritanides: Implications for the geodynamic evolution of West Africa

Neoproterozoic and Hercynian metamorphic events in the Central Mauritanides: Implications for the geodynamic evolution of West Africa

Geochemical Evidence for Large‐Scale Drainage Reorganization in Northwest Africa During the Cretaceous

The palaeogeographic position of Central Iberia in Gondwana during the Ordovician: evidence from zircon chronology and Nd isotopes

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