A Multi-Parameter Approach to Nearshore Seabed Mapping of the Al-Lith Area
Najeeb M.A. Rasul, Salem Al Nomani, Fares Z. Bahareth, Omar Al Hazmi, Nawaf A. Widinly,
Mansour Abushosha, and Abdulnasser S. Qutub
Three different sources of sediments have been identified: terrigenous (wadis), biogenous (calcium carbonate) and aeolian (wind transported). Sporadic coral patches are also present in the study area that restricts the sediment movement. Most of the terrigenous material supplied by Wadi al Ghallah to Khor al Ghallah is dispersed in the southerly direction, whereas the sediment from Al-Lith and Wadi Iyar is transported in the easterly direction by the littoral current. Surface current plays a major role in the distribution of mica. Sediment colour is related to the source material, whereby restricted sediment movement due to the occasional water flow induces a reducing environment locally that helps in the formation of pyrite, resulting in the staining of the shell debris black. Sandy mud texture and multiple sediment sources and fragmentation of biogenic material deteriorate the sorting values. Generally with an increase in calcium carbonate the organic carbon decreases.
Rasul, N.M.A., Al-Nomani, S., Bahareth, F.Z., Al-Hazmi, O., Widinly, N.A., Abushosha, M. and Qutub, A.S., 2009, A multi-parameter approach to nearshore seabed mapping of the A-Lith area: Saudi Geological Survey Technical Report SGS-TR-2008-10, 50 p., 19 figs., 8 tables.