Multidisciplinary geological analysis of the Trigueros Sand Unit (Gibraleon Clay Formation, SW Spain)

This paper defines the main sedimentological, palaeontological and geochemical features of the Trigueros Sand Unit, deposited during the Messinian in a global context of falling sea level. This unit is notably different from the rest of the Gibraleon Clay Formation due to its larger grain size, the presence of stormy levels formed by bivalves typical of circalittoral environments, an infralittoral ostracod association in its upper sandy levels and a lower content of both trace elements and rare earths. Together, these characteristics would identify the deposition of turbidites in a low-energy circalittoral environment, whose bottom suffered erosive episodes and where sediments transported from shallow neritic environments also concurred, within a distal area of ancient deltas.