Reconnaissance investigation of evaporites and brines of the Eastern Province, Kingdom of Saudi Arabia

Abstract

In the Eastern Province of the Kingdom of Saudi Arabia from south of Al Hasa oasis (about lat 25? N., long 50? E.) north to near the southern border of the neutral zone between Saudi Arabia and Kuwait (about lat 28? N., long 48? E.), sabkhah-associated brines form either by solar evaporation of near-surface ground water or by dissolution of previously precipitated saline minerals in the subsurface. Most sabkhah-associated brines have evolved from fresher ground water by the process of solar evaporation. One of the major controls of sulfate, calcium, and bicarbonate concentrations in brines is equilibrium reactions of these ions with authigenic minerals in sabkhah sediments. Although equilibrium reactions also provide some control of concentrations of magnesium, potassium, sodium, and chlorine, the concentrations of these elements in brines are controlled primarily by the degree to which the solutions have evaporated. Salt for industrial use in the Eastern Province is currently supplied from the Ra's al Qurayyah and Aba al Hamam bedded salt deposits, both of which are naturally exposed. At Jayb Uwayyid, a bedded salt deposit approximately 3.5 m below the sabkhah surface is not currently exploited. Except on a small scale, brines in the Eastern Province are not being utilized, either directly or for the production of salt. The Jayb Uwayyid deposit has some potential for industrial utilization of brine and salt, and further exploration for this type of salt deposit is probably warranted.