MSA AWARD LECTURE: MINERALOGY AS A BRIDGE BETWEEN GEOCHEMISTRY AND EARTH HISTORY

The language of planetary surface evolution is written in mineralogy. For at least four billion years, sedimentary and tectonic processes on both Earth and Mars have continuously transformed mineral products against a dynamically evolving environmental backdrop. Unraveling the paleo-environmental overprint captured by many sedimentary successions hinges on understanding mineral stability in depositional, diagenetic, and metamorphic environments. As many researchers before us have so clearly shown, experimental and theoretical approaches offer important avenues of investigating mineral stability in ancient geochemical systems, and they underpin the successful application of many geochemical and isotopic proxies for environmental change. Our research has greatly benefited from advances in materials characterisation and probing molecular scale interactions, taking explicit account of physical and chemical dynamics of sedimentary environments, and wherever possible, connecting experimental products to the sedimentary record through crystallography and mineral chemistry. Together this approach is providing new constraints on early diagenetic chemistry, redox dynamics, and biogeochemical cycling through Earth’s history and revealing unexpected geochemical consequences of sedimentation on the early martian surface.