Sedimentology and geochemistry of Qurayyah Sabkha, Eastern Saudi Arabia

(1994) Sedimentology and geochemistry of Qurayyah Sabkha, Eastern Saudi Arabia. Masters thesis, King Fahd University of Petroleum and Minerals.


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The Qurayyah Sabkha is located on the western coast of the Arabian Gulf in Eastern Province of Saudi Arabia. The sabkha is a salt flat and low depression that is approximately 5 km in diameter. The depression is characterized by a permanent water ponding with a thick crust of halite close to the southeastern edge of the sabkha. The halite crust is continuously dissolved and redeposited as a result of water level fluctuations associated with the influx of rain water. The sabkha geomorphology and sedimentology are greatly influenced by the predominantly northwestern offshore winds that continuously supply eolian sand to the sabkha sediments. Accordingly, the evaporite sedimentation is primarily found on the downwind side of the sabkha. The sabkha sediments are dominated by four minerals; gypsum, anhydrite, halite and quartz sand. The sedimentary facies is characterized by central halite crust at the margin of the water ponds surrounded by gypsum mush facies downwind from the central halite, and a brown mud composed of gypsum, anhydrite, halite, and quartz sand covered by a thin polygonal gypsum crust upwind from the central halite zone. The brine salinity increases with the rise of water level following rain fall and decreases in the summer when relatively fresh groundwater replaces the evaporation loss. The brine becomes slightly oversaturated or in equilibrium with respect to gypsum, halite and anhydrite during the period of higher salinity. The stable isotope data of the sabkha brine show enrichment of all the stable isotopes except for deuterium. The enrichment is indicative of strong evaporation most probably of Neogene groundwater. The ¹⁴C data suggests a component of old groundwater in the brine that is continuously rejuvenated by the aquifer waters.

Item Type: Thesis (Masters)
Department: College of Petroleum Engineering and Geosciences > Geosciences
Committee Advisor: Cagatay, Mehmet Namik
Committee Members: Weijermars, Rudy and Irtem, Oguz and Al-Ukayli, Mustafa A.
Depositing User: Mr. Admin Admin
Date Deposited: 22 Jun 2008 13:52
Last Modified: 02 Aug 2021 06:03