Nouvelles datations de l'Asbien supérieur/Brigantien inférieur (Viséen supérieur, Mississippien) dans la formation du Mouchenkour (Maroc central) : conséquences paléogéographiques

Des lentilles gréso-carbonatées et des olistolithes calcaires permettent d\u27attribuer un âge Asbien supérieur/Brigantien inférieur (biozone marocaine Cfm7) à la partie moyenne de la formation siliciclastique du Mouchenkour. Ces niveaux sont caractérisés par les algues problématiques Ungdarella, Fasciella et Koninckopora et les foraminifères Archaediscus (au stade concavus), Pseudoendothyra et Eostaffella. Un modèle fondé sur les relations des milieux de dépôt de l\u27Asbien/Brigantien local permet de reconstituer différentes unités paléogéographiques, du Tizra, au nord-ouest, au Mouchenkour, au sud-est. Le déplacement de ces unités est probablement très faible et a peu modifié leurs relations initiales.New datings of calcareous sandstone lenses and olistolites exposed in the middle part of the siliciclastic Mouchenkour Formation indicate a Late Asbian/Early Brigantian age (Cfm7/Cfm8 Moroccan biozone). The calcareous microfossil assemblages are characterized by the problematic algae Ungdarella, Fasciella and Koninckopora and foraminifers Archaediscus (concavus stage), Pseudoendothyra and Eostaffella. An Asbian/Brigantian palaeogeography based on the depositional environments is reconstructed from northwest to southeast, from the Tizra to the Mouchenkour areas. The units, although in tectonic contacts, nearly preserve their initial location and relations.</p

New Late Asbian/Early Brigantian (Late Visean, Mississippian) dates in the Mouchenkour Formation (central Morocco) : palaeogeographical consequences.

International audienceNew datings of calcareous sandstone lenses and olistolites exposed in the middle part of the siliciclastic Mouchenkour Formation indicate a Late Asbien/Early Brigantian age (Cfm7/Cfm8 Moroccan biozone). The calcareous microfossil assemblages are characterized by the problematic algae Ungdarella, Fasciella and Koninckopora and foraminifers Archaediscus (concavus stage), Pseudoendothyra and Eostafella. An Asbien/Brigantian palaeogeography based on the depositional environments is reconstructed from northwest to southeast, from the Tizra to the Mouchenkour areas. The units, although in tectonic contacts, nearly preserve their initial location and relations

The Late Visean Azarhare series (central Morocco): deposition environments, dating and diagenetic evolution.

International audienc

The Late Visean Azarhare series (central Morocco): deposition environments, dating and diagenetic evolution.

International audienc

Le Carbonifère inférieur de la région d' Agouraï (Nord du Maroc central) : faciès, biostratigraphie et paléogéographie

The Lower Carboniferous of the Agouraï area (North of central Morocco) : facies, biostratigraphy and paleogeography. The Lower Carboniferous outcrops of Agouraï area are composed by three formations. Hie environmental evolution is from detritic coastal deposits and carbonate shelf deposits to open shelf deposits. Ages are from Middle Visean (V2a-V3a) to Upper Visean (V3ba, probably V3bP). Hie V2a-V3a is particularly well-characterized and can be examplified for a Moroccan Visean scale.Les terrains du Carbonifère inférieur de la région d'Agouraï s'organisent en trois formations qui passent de dépôts littoraux détritiques à des dépôts carbonatés de plate-forme interne peu profonde puis à des dépôts de décantation de milieu ouvert. Ils sont datés du Viséen moyen (V2a -V3a) au Viséen supérieur (V3ba, probablement V3bP). Le V2a-V3a est particulièrement intéressant et peut servir de modèle pour une échelle marocaine.Berkhli Mostafa, Vachard Daniel, Paicheler Jean-Claude, Tahiri Abdelfattah, Saïdi Amal. Le Carbonifère inférieur de la région d' Agouraï (Nord du Maroc central) : faciès, biostratigraphie et paléogéographie. In: Géologie Méditerranéenne. Tome 27, numéro 1-2, 2000. pp. 71-79

Potential foraminiferal markers for the Visean-Serpukhovian and Serpukhovian-Bashkirian boundaries- A case-study from Central Morocco

Potential foraminiferal markers for the Visean-Serpukhovian and Serpukhovian-Bashkirian boundaries- A case-study from Central MoroccoThe Carboniferous succession in Adarouch (Central Morocco, north of the Atlas Transform Fault) contains thick carbonate beds including upper Visean, Serpukhovian and basal Bashkirian rocks. Foraminifers enable precise recognition of the Visean/Serpukhovian (V/S), early/late Serpukhovian (eS/lS) and Serpukhovian/Bashkirian (S/B) boundaries. Insolentitheca horrida, Loeblichia ukrainica, "Millerella" spp. and Endostaffella? sp. 2 are regarded as regionally useful indices to the V/S boundary, whereas Eostaffellina spp., Eostaffella pseudostruvei and some evolved species of Archaediscus exhibit greater reliability for worldwide correlation of this level. Similarly, the eS/lS boundary is marked locally by Brenckleina rugosa, Eosigmoilina sp., and Monotaxinoides spp. and globally by Loeblichia minima, Bradyina cribrostomata, Plectostaffella spp., Eostaffellina "protvae" and "Turrispiroides", and the S/B boundary is marked locally by Globivalulina bulloides and globally by Seminovella elegantula, and Novella?. Ocurrences of these taxa in Morocco allow correlations with the Moscow Basin, the Urals, the Donetz Basin and North America. The Moroccan assemblages share few taxa in common with Saharan basins south of the Atlas Transform Fault. Correlations with western European basins are difficult because of the paucity in the latter of foraminiferal-bearing carbonate strata