Late Visean-Serpukhovian foraminiferans and calcareous algae from the Adarouch region (central Morocco), North Africa

Three Upper Visean to Serpukhovian limestone formations from the Adarouch region (central Morocco), North Africa, have been dated precisely using foraminigerans and calcareous algae. The lower and middle part of the oldest formation, the Tizra Formation (Fill), is assigned to the latest Asbian (upper Cf6 gamma Subzone), and its upper part to the Early Brigantian (lowerCf6 delta Subzone). The topmost beds of this formation are assigned to the Late Brigantian (upper Cf6 delta Subzone). The lower part of the Succeeding Mouarhaz Fill is also assigned to the Late Brigantian (upper Cf6 delta Subzone). The Akerchi Fill is younger than the other formations within the region, ran-im, from the latest Brigantian (Uppel-MOSt Cf6 delta Subzone) up to the Serpukhovian (E-1-E-2). The base of the Serpukhovian (Pendleian Substage, E-1) is repositioned. to coincide with the appearance of a suite foraminiferans, including Archaediscus at tenuis stage, Endothyranospsis plana, Eostaffella pseudostruvei, Loeblichia ukrainica, Loeblichia aff. minima and Biseriella? sp. 1. The upper Serpukhovian (Arnsbergian Substage, E,) is marked by the first appearance of Eostaffellina ex. gr. paraprotvae and Globoomphalotis aff. pseudosamarica. The biostratigraphical scheme used for the reassessment of the foraminiferal zones and subzones in the Adarouch area closely compares with that for the British succession in northern England (Pennine Region), where the stratotypes of the Upper Visean (Asbian and Brigantian) and Early Serpukhovian (Pendleian) substages are located. Thus, a succession equivalent to an interval from the Melmerby Scar Limestone to the Great (or Little) Limestone is recognized. These assemblages are also compared to other foraminiferal zones proposed in other regions of Morocco. Several foraminiferans have been identified that are proposed its potential Serpukhovian markers for other basins in Western Europe, and compared to sequences in Russia and the Donets Basin. Ukraine. Copyright (C) 2008 John Wiley & Sons. Ltd.