Sedimentary reflections of the coastal processes on the shore zone sediments along the eastern Red Sea coast, Saudi Arabia

The intent of this paper is to provide a background to the regional trends in textural parameters and mineral associations along the shore-zone betwee n Rabigh coast and near the outlet of Sharm al-Kharrar in the eastern Red S ea coast. The behavior of the sediments in the shore zone profile varies with differe nt subenvironments. Sediments in the nearshore (breaker) zone, have the coa rsest grain size and the poorest sorting, and improve in sorting both shore ward and seaward. Variations in texture are related to the kind of sediment process transport. The analysis of the constructed grain-size distribution curves explains the sedimentary process dynamics. It was found that al-Kassara reefal bar plays an important role for the tex tural composition of the sediments in the shore zone along the eastern Red Sea coast, where coarse sediments are dominant due to the erosive power of waves. The heavy mineral suite of the shore zone sediments has dominant less stabl e minerals (amphiboles, pyroxenes and epidotes), while the ultrastable mine rals (zircon, tourmaline and rutile as well as opaques) display a considera ble concentration in the shore zone sediments at Rabigh coast reflecting an additional provenance. The hydrodynamic forces seem to increase at Rabigh coast so the relative sorting by water during storms may produce heavy mine ral concentration and concave shoreline. The shore zone sediments are composed mostly of skeletal carbonate sands. H igh Mg-calcite and aragonite are the dominant carbonate minerals like the s hallow water carbonate in tropical seas.