The origin of the Pliocene to recent succession in the Levant basin and its depositional pattern, new insight on source to sink system

Abstract

The Pliocene-to-Recent succession in the deep Levant basin is coeval to the development of the Nile River delta and to the progradation of the thick (~1500 m) Sinai-Israel shelf. It hides a series of paleo-channels exhibiting transportation and sedimentation patterns revealing a world class source to sink system feeding a deep (>1500 m) siliciclastic basin. The general agreement that the Pliocene-to-Recent succession originates from the Nile Delta dispersing sediments via a system of counterclockwise currents does not reveal how the sediments were transported to the deep basin. Particularly, how sediments originating from the Nile Delta could have bypassed the ~50 km wide Sinai-Israeli shelf. Here, we examine the various sources that contributed to the accumulation of the Pliocene-to-Recent succession in the deep Levant basin, and the temporal and spatial contribution of each source. Analysis of a unique seismic data set covering the shelf, slope and deep basin enable us to track submarine sediment transport systems; we map channel sets, analyze their morphological features and interpret their erosional and depositional patterns. We argue that sediments sources vary from eastward remnant Arabian drainage network at the onset of the Pliocene, to Nilotic origin during the Pliocene. Since the Late Pleistocene reworked sediments, deriving from the Israeli shelf and northern Sinai provide a major source to the deep basin. Furthermore, our results demonstrate an increase in channel's complexity since the Early Pliocene to Recent, suggesting a gradual transition from sporadic submarine flow events, carrying fewer sediments to the deep basin at the Early Pliocene, to more frequent events during the Late Pleistocene-to-Recent characterized by an increase in sediment load. The gradual increase of channel complexity from Pliocene-to-Recent is discordant to the general trend of sea-level fluctuation, suggesting that sea-level has a minor effect on sediment accumulation in the deep basin.