Cl/Br compositions as indicators of the origin of brines: Hydrogeologic simulations of the Alberta Basin, Canada

Abstract

Research Article| January 01, 2012 Cl/Br compositions as indicators of the origin of brines: Hydrogeologic simulations of the Alberta Basin, Canada Ipsita Gupta; Ipsita Gupta † 1Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA †E-mail: [e-mail] Search for other works by this author on: GSW Google Scholar Alicia M. Wilson; Alicia M. Wilson 1Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA Search for other works by this author on: GSW Google Scholar Benjamin J. Rostron Benjamin J. Rostron 2Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Ipsita Gupta † 1Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA Alicia M. Wilson 1Department of Geological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA Benjamin J. Rostron 2Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada †E-mail: [e-mail] Publisher: Geological Society of America Received: 17 Jan 2010 Revision Received: 15 Oct 2010 Accepted: 02 Dec 2010 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2012 Geological Society of America GSA Bulletin (2012) 124 (1-2): 200–212. https://doi.org/10.1130/B30252.1 Article history Received: 17 Jan 2010 Revision Received: 15 Oct 2010 Accepted: 02 Dec 2010 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Ipsita Gupta, Alicia M. Wilson, Benjamin J. Rostron; Cl/Br compositions as indicators of the origin of brines: Hydrogeologic simulations of the Alberta Basin, Canada. GSA Bulletin 2012;; 124 (1-2): 200–212. doi: https://doi.org/10.1130/B30252.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The origin and residence time of brines in the Alberta Basin have been debated for more than 40 years, with conflicting conclusions reported by geochemical and hydrogeologic studies. Here, numerical models were used to determine hydrogeologically feasible scenarios for the origin of brines in the Alberta Basin, using salinity and Cl/Br ratios as geochemical constraints. The models simulated variable-density fluid flow, heat transport, solute transport, and sediment compaction and decompaction in the Alberta Basin over the last 100 m.y. Simulation results suggest that pore fluids in this basin represent a mixture of four geochemical end members: seawater, freshwater, brines formed by evaporation of seawater, and, contrary to prior interpretations of Cl/Br ratios, brines derived from halite dissolution. Sensitivity studies revealed that similar distributions of salinity and Cl/Br ratios could be obtained without dissolution of halite if extremely low permeabilities were used in the model, but this scenario conflicts with field-based permeability data and prior simulations of petroleum migration in the basin. The residence time of brines in the Alberta Basin has thus likely been overestimated. The presence of evaporites introduces significant uncertainty in the use of Cl/Br ratios for interpreting the origin of brines in sedimentary basins, but salinity and Cl/Br ratios provide valuable new constraints for regional-scale models. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.