Sedimentological and paleontological study of the tidal flat recent sediments of Khor Al-Zubair and Khor Abdullah, Northwest Arabian Gulf

الملخص EN

The present study deals with sedimentological and paleontological aspects of the tidal flats recent sediments of Khor Al- Zubair and Khor Abdullah.

The sediments of these tidal flats are mainly composed of silt and mud.

Carbonate content was 7.83–26.58 % and 23.38-45.54 % in the sediments of the tidal flats of Khor Al-Zubair and Khor Abdullah, respectively and the percentage of organic carbon was 0.025-0.9 % in the sediments of Khor Al-Zubair tidal flats while the percentage in Khor Abdullah tidal flats sediments was 0.44-0.87 %.

The main constituents of non–clay minerals were calcite, quartz and feldspar in the two tidal flats.

Foraminifera, Ostracoda, Gastropoda and Pelecypoda were identified to determine the biofacies of these tidal flats.

Four biofacies were identified in the sediments of Khor Al-Zubair tidal flats ; BZ1 is a marine environment facies with estuarine condition, BZ2 is a mangrove swamp environment, BZ3 is a lagoonal environment of high salinity, and BZ4 is a brackish–marine environment.

The biofacies of Khor Abdullah tidal flat sediments were BA1 and BA2 of marine and nearly marine environments, respectively, whereas, the biofacies of Khor Abdullah channel were BC1 and BC2 which represent the ends of delta and the biofacies BC3 and BC4 show a lagoonal environment.