Physical Sciences and Mathematics Commons^™

Low Salinity Waters In Deep Sedimentary Basins, David Scott Szalkowski

LSU Master's Theses

While the composition and origin of brines in deep sedimentary basins has been extensively discussed, the composition and origin of low salinity waters is not as well documented. Since the 1960s, the presence of deep, low-salinity waters has been observed in some sedimentary basins and is commonly present in overpressured sections. The episodic release of low salinity, overpressured fluids upward into sediments containing high salinity formation waters likely occurs at <100-year intervals. Because there is a growing body of evidence that suggests mixing formation waters of varying salinity could induce the dissolution and precipitation of minerals, it is important to have detailed information about chemical compositions of both end-member fluids to adequately predict such mixing results. This study concludes that low salinity waters (<35 g/l) are generally not unique in major solute composition when compared to high salinity waters (>35 g/l). On log-log plots, monovalent cations plot along 1:1 slopes with respect to salinity and total anionic charge, while divalent cations plot along 2:1 slopes. However, this study concludes …