The Tindouf Basin, a marine refuge during the Serpukhovian (Carboniferous) mass extinction in the northwestern Gondwana platform

Abstract

Several macrofaunas and microfossils of the Carboniferous Saharan basins have longer stratigraphic ranges than those of other basins in the western Palaeotethys realm, particularly in the Tindouf Basin (Morocco–Algeria). Foraminifers are particularly abundant and diverse in the Serpukhovian and basal Bashkirian compared to coeval basins, and some taxa have longer ranges than in the neighbouring Reggan and Béchar basins, although this effect is more marked compared to the western Palaeotethyan assemblages in Europe. Several rugose coral species are recorded from the early Bashkirian that previously were considered to have disappeared in the Serpukhovian. The Tindouf Basin, as one of the most western Saharan basins in North Africa, shows the greatest stratigraphic ranges of taxa which diminish eastwards. Evidence for a mass extinction event during the Serpukhovian in the Tindouf Basin has not been clearly recognized, although a possible influence of glaciation is observed in the faunal diversity. Eustatic sea-level changes were experienced in Tindouf with the cyclic pattern of sedimentation, but warm water ocean currents from the palaeoequator were able to maintain tropical conditions on the platform. Tectonics in the area, led to emerging land masses and barriers, and created a partly isolated basin in this sector of the western part of the Sahara Platform in northern Gondwana. The combination of those factors controlled the environmental conditions in the area, allowing the persistence of the fauna for longer stratigraphic ranges than its equivalent counterparts in the western Palaeotethys.