Development of sedimentation along the Saudi Arabian Red Sea coast

Abstract EN

Synrift sediments along the Arabian Red Sea coast are generally subdivided into a basal continental unit, a transgressive marine series, an evaporitic formation and a final mixed clastic-carbonate sequence.

These facies changes mark characteristic steps of the gcodynamic evolution.

Detailed studies were carried out in the northern part of Midyan and along the coast between Aynunah and Yanbu as well as around Jizan.

Findings of fossils and new absolute age determinations provide a better understanding of the chronological development.

The Oligocene and Miocene synrift sediments are exposed at different places.

In the Midyan area continental and marine units can be distinguished.

They range from Rupelian to Serrava- lian in age, and exist generally with greater thicknesses within the axial part of the graben basin.

The oldest synrift deposits of southwestern Arabia are formed by an association of non- marine sediments, volcanics and volcanoclastics.

They are coeval with marine strata at the northern Red Sea and prove that early rifting in the Oligocene occurred along the entire length of the then Red Sea basin.

The Pliocene-Pleistocene sequence is separated by a major late Miocene unconformity.

These younger sediments along the coastal plain consist mainly of calcareous sandstone or cal- carenite with intercalations of reef and littoral or fluviatile sandstone and conglomerate.