Magnetobiostratigraphy of a Late Miocene section from the Moroccan Atlantic margin

Abstract

Paleomagnetic study of a Late Miocene section from Atlantic Morocco correlated with detailed biostratigraphic data suggests an assignment of the observed polarity sequence to the uppermost part of chron 7, to entire chron 6 and to the beginning of chron 5. Comparison with time equivalent sections in the Southern Hemisphere does not suggest noticeable delay in long faunal migration (between the Northern and Southern Hemisphere) during the late Miocene. Thus the postulation of a delay in arrival of species in the Eastern Mediterranean at the base of the Messinnian has to be explained by the presence of selective barriers which could have been located either between the Mediterranean and Atlantic or between the Western and Eastern Mediterranean in the basins delineated during the final evolution of the Tethys. This study also indicates a possible application of biomagnetostratigraphy to the reconstruction of basin interconnections.