Join us for our next ESG Seminar Series speaker, Dr. Megan Madden. Dr. Madden is a Professor in the Department of Earth and Environmental Sciences at Michigan State University. Dr. Madden studies planetary geochemistry. She and her students actively apply what they and other geochemists have learned about minerals, fluids, and rocks on Earth to understand fluid-rock interactions, mineral assemblages, and suites of rocks on other planets. Through experiments in the lab and field, they explore mineral stability, reaction rates, and the resulting reaction products that form in low-temperature (and often salty) planetary systems, including planetary-analog environments on Earth. Join us for this exciting seminar!

Dr. Megan Madden
Michigan State University
Department of Earth and Environmental Sciences

Mars Chemical Weathering - A Salty Cocktail on the Rocks?

If we “follow the water” throughout our Solar System, we also find lots of salt. Salts deposits are widespread on Mars and Ceres where they can lower freezing points to maintain liquid water on planetary surfaces. Salts may also play a key role in stabilizing subsurface oceans on icy moons.  Therefore, salty water is probably the norm throughout the Solar System. Even on Earth--likely the freshest planet-- 97% of surface water is salty. To understand and interpret aqueous processes in these systems, we must consider how brine-rock interactions affect chemical weathering. Indeed, brine-rock interactions can lead to unexpected aqueous chemistries, alteration rates, and mineral assemblages even at very low water-rock ratios, including cation exchange and dissolution reactions in nanoscale films formed through deliquescence of water vapor from the atmosphere.