Abstract
An analysis of the cyclostratigraphic potential of black shales is proposed from the study of the Albian part of the Marne a Fucoidi Formation of the Umbria-Marche basin (Central Italy). The succession, about 65 m thick, is constituted by marl-limestone alternations in which are intercalated numerous black shales (150). Firstly, the spatial arrangement of black shales was studied on an interval approximatly 42 m thick along a 40 km transect in order to verify the homogeneity of the succession. Secondly, a cyclostratigraphic approach was applied on the temporal distribution of black shales. The genetic significance of black levels was discussed from their petrologic characteristics (mineralogic, palynologic and geochemical). The depositional model obtained was compared with the model of deposition for the Mio-Pliocene sapropels of the Mediterranean. A temporal significance of black shales is then advanced. A potential use of the spatio-temporal distribution of these singular levels in pelagic realm is proposed.
