8 Summary and Conclusion

This book provides an introductory conceptual overview of the most common processes of shallow brine and evaporite mineral formation, not a thorough scholarly review of the literature. Each of the processes has been discussed in excellent research papers and the cited references lead the reader to a more complete body of literature. Whereas the field examples presented herein are of limited geographical distribution, the principles are applicable worldwide and illustrate the subtleties of shallow saline systems. Although evaporation is critical to water removal, the degree of leakage of a system and the solubility of minerals control the evolution of solute concentrations and mineral precipitation. The loss of mass in the gas phase is also important for several elements and needs to be included in mass balance calculations.

Science involves a thought process that allows us to anticipate future conditions thus, it is useful to ask how understanding of near surface brine/evaporite systems helps in predicting the future of these and similar systems. As climate is rapidly changing, Earth’s arid and semi-arid areas are expanding. By studying current and paleo examples of near surface brine/evaporite systems, we can predict how water that is discharged to the surface will behave in these expanded arid areas and how changes in water use (e.g., due to changes in vegetation or groundwater development) will impact brine evolution. Such study also facilitates exploration for economically valuable evaporite deposits when coupled with our expanding knowledge of paleo regional-flow systems and paleoclimate. Understanding how a deposit forms aids in estimating the economic reserves and evaluating how active systems will respond to development of groundwater resources, as well as changes in precipitation and evaporation. In short, knowledge of the origin and evolution of current systems improves our confidence in predicting the development and evolution of similar systems in the future.