Geochemistry and isotopic analysis of brines in the coastal sabkhas, Eastern region, Kingdom of Saudi Arabia. (July 2020)

• Record Type: Journal Article
• Authors: Hussain, Maaruf; Al-Shaibani, Abdulaziz; Al-Ramadan, Khalid; Wood, Warren W.
• Is Part Of: Journal of arid environments. Volume 178(2020)
• Publication Date: 2020-07
• Subjects: Ascending brine model -- Sabkha -- Sabkha solutes -- Sabkha geochemistry -- Evaporites; Arid regions ecology -- Periodicals; Arid regions -- Periodicals; Écologie des régions arides -- Périodiques; Régions arides -- Périodiques; 577.54
• DOI: 10.1016/j.jaridenv.2020.104142
• Languages: English
• ISSNs: 0140-1963

Abstract

Abstract: Several solute-source models have been proposed to elucidate the origin of the solutes in the Gulf coastal sabkhas. The Ascending Brine hydrogeologic model has been shown to be a viable explanation for the origin of solutes in the Arabian (Persian) Gulf coastal sabkha in the UAE (United Arab Emirates). A coastal sabkha approximately 500 km northwest of the UAE sabkha and 40 km northwest of Dhahran, Kingdom of Saudi Arabia was selected to test the general applicability of this conceptual model. The Cl and Br relationship was used to assess the source of solutes in combination with the activities of 226 Ra, and bromine isotopes δ 81 Br. The possible origin of water in the system was constrained using isotopes of δ 18 O, δ 2 H, and activity of 3 H. The analyses of Cl − /Br −, 226 Ra activity and bromine isotopes δ 81 Br indicate solutes are consistent with the Ascending Brine model and incompatible with seawater based models. Isotopes of δ 18 O, δ 2 H, and activity of 3 H suggest most of the water is from local precipitation. Whereas the geology, solute chemistry, and mineral sequence is different in both sites, water and solute isotopes at this site are consistent with the proposed Ascending Brine model. Highlights: Sabkhas are important features in the Gulf, so are Paleo-sabkhas for petroleum studies. Ascending brine model explains sabkha solute origin based on Abu Dhabi Sabkha study. Current study attempted to test whether the model is applicable to other coastal areas. Geology, solute chemistry, and mineral sequence are different in both sites. Solute fingerprint and isotopes are consistent with the Ascending Brine model.