Prograding clastic fans and transition from a fluviatile to a marine environment in Neogene deposits of Eastern Crete

Abstract

In Neogene deposits of the eastern Sitia district (eastern Crete), a lateral succession from fluviatile to marine deposits has been reconstructed. Paleocurrent analysis indicates mainly southwest-directed sediment transport. The reddish deposits in the east (Kastti Formation) display braided-river characteristics. The fluviomarine deposits in the central part of the area (Toplou Formation), lie laterally of the braided-river deposits eastward. The fluviomarine deposits include thick conglomerate sheets, which display giant foresetting in sets between 5 and 30 m. high. This giant foresetting probably reflects the depositional slopes of large fans built by the discharging river below sea level. The submarine nature of deposition is confirmed by Ostrea between or on the pebbles. In the extreme southwestern part of the area marine marls occur (Akhladia Formation) with clastic intercalations, which bear evidence of mass transport, and which probably have been derived from the discharging river courses northeastward. Uniserial Uvigerina and Globorotalia in these marine marls point to a Late Miocene age of these deposits and hence of the fluviomarine and the fluviatile sediments.