A quantitative analysis of Recent arid coastal sedimentary facies from the Arabian Gulf Coastline of Abu Dhabi, United Arab Emirates

This study presents the results of the first quantitative analysis of surface sediments along multiple transects of the Arabian Gulf shoreline of Abu Dhabi, United Arab Emirates. The natural coastline of this low-angle carbonate ramp depositional system is being anthropogenically modified at an unprecedented rate. As this system is much-employed as a Recent analogue for many ancient depositional sequences, it is imperative that sedimentological characteristics of natural fades occurrences are accurately recorded for employment in future applications. We establish distinct relationships between the geomorphic setting and sediment characteristics. Siliciclastic grains admixed to this system are naturally sourced from the Pliocene Ghayathi Formation and from aeolian sediment influx during dust storms. This natural source of siliciclastic detritus is being increasingly superseded by siliciclastic material derived from anthropogenic activities. Evaporite minerals are similarly being contributed from anthropogenic sources. The occurrence of mud to silt grade sediments is primarily controlled by the presence of a sediment-binding microbial mat that prevents the removal of fine material during high energy events. Similarly, the presence of a halite crust in the upper tidal flats and supratidal zone prevents aeolian deflation. This study did not establish any clear relationship between coastal geomorphic setting and the bioclastic components present in the sediments. This finding has major implications for the application of bioclasts in fine-tuning palaeoenvironmental interpretation of ancient carbonate ramp coastal systems. (C) 2013 Elsevier B.V. All rights reserved.