Neritic–pelagic correlation in the Lower and basal Middle Devonian of the Dra Valley (Southern Anti-Atlas, Moroccan Pre-Sahara)

Abstract

Abstract Marine Lower Devonian successions are widely exposed in the Dra Valley (Southern Anti-Atlas, Moroccan Pre-Sahara). Resulting from new studies, especially on brachiopods, conodonts, and dacryoconarid tentaculitids, the chronostratigraphic assignments of the Lower Devonian formations are revised. Thanks to lateral and vertical facies variations, it is possible to correlate pelagic and neritic successions and corresponding biostratigraphies. Pelagic conodont, dacryoconarid and goniatite faunas allow correlations and dating in the sense of the Bohemian and global chronostratigraphies, whereas units of the traditional Rhenish subdivision can be identified by means of neritic brachiopods.