Signature of hydrodynamic activity caused by rapid sea level changes in pelagic organic-rich sediments, Tarfaya basin (southern Morocco)

Abstract

Abundant beds with calcareous tempestites, hummocky cross-stratifications ‘HCS’, bioclastic limestones ‘BL’ and limestone channels ‘LCh’ occur in the Late Cretaceous sequence (Middle-Late Cenomanian / Early Turonian) of the Tarfaya basin (SW Morocco) with a strongly erosive base. Results of the study have significant implications for sea level fluctuations in fine-grained basinal facies. According to the palaeoenvironmental reconstructions, the strata were deposited in the offshore area dominated by an upwelling system. The regular distribution of the ‘BL’, ‘HCS’ and ‘LCh’ throughout the section provides a constraint on palaeobathymetry. The water depth during deposition fluctuated frequently and ranged from below, but near, storm wave base.