A Comparative Study of Facies and Diagenesis of Arabian Peninsula Sabkhas
Jeremy Jameson1*, Christian J. Strohmenger2, and Michael Kozar1
Models of modern and ancient sabkhas tend to be biased by the extensive studies on the Holocene coastal sediments of the United Arab Emirates. Results from the present study and other recent studies along the coastlines of the Arabian Peninsula provide new insights into the variability of sabkha systems. These results reveal that modern sabkhas vary in facies types, facies proportions, evaporite-mineral suite and water chemistry. Antecedent topography, winds, currents, the Holocene sea-level rise and fall, and sediment supply are primary controls on sabkha sedimentation and diagenesis. Based on these controls, continental, coastal-carbonate and coastal-clastic sabkhas are recognized and have differing implications for facies, diagenesis and reservoir-quality distribution. Arabian Peninsula sabkhas have a common sea-level history. Most formed after a Holocene sea-level highstand approximately 4,000 to 6,000 years before present. Sabkhas have in common a very low relief, deflation, depositional surface. Consequently, very little hydrostatic head develops within sabkha sediments. Topographic relief from proximal headlands is sufficient to introduce meteoric waters into sabkha systems. Antecedent relief is an equally important control on marine circulation systems and consequent sediment-dispersal patterns. Sedimentary responses to physical processes like wind and marine circulation led to the development of a range of facies patterns observed in sabkhas. Knowledge of how physical controls may interact helps in the application of sabkha models to reservoir prediction and characterization. Like all sedimentary systems, sabkhas record an interplay of controls. Accordingly multiple working models should be considered in characterizing other modern and ancient sabkha systems.
AAPG Search and Discovery Article #90077©2008 GEO 2008 Middle East Conference and Exhibition, Manama, Bahrain