New biostratigraphic, petrographic and sedimentological investigations on Saf Lahmame marly-arenaceous succession of the External Tanger Unit (Intra-Rif sub-Domain, External Domain) indicate an age not older than Burdigalian–Serravallian. The medium- to fine-grained sandstones of the Saf Lahmame succession show mainly graded and massive amalgamated beds organized in thinning- and fining-upward sequences. Medium-grained deposits reflect a continual process of aggradation beneath a high-density turbidity current and by a very quick deposition for freezing of a dense cohesionless suspension under a highly concentrated flow. A fine-grained facies association reflects slow accumulation of mud and biogenic materials and diluted and low concentration turbidity currents. The sandstones of the sublitharenite/quartzarenite groups are characterized by common occurrence of glauconite grains. Their provenance seems to be exclusively related to the African Craton, which is in good agreement with the published data on the composition of the Numidian and Numidian-like sequences in the Rif, Betic and Apenninic-Maghrebian Chains. The SE and NW paleoflows within these sandstones could reflect a multisource alimentation from instable marginal areas of the Africa.
|Titolo:||Stratigraphy and provenance of Lower and Middle Miocene strata within the External Tanger Unit: (Intra-Rif Sub-Domain, External Domain; Rif, Morocco): first evidence|
|Data di pubblicazione:||2005|
|Appare nelle tipologie:||1.1 Articolo in rivista|