Dr. Geoff Gilleaudeau
I am a sedimentologist, stratigrapher, and geochemist with a strong interest in Earth history, particularly the chemical evolution of the ocean-atmosphere system. My research falls into two broad categories: 1) understanding redox balance, trace metal availability, and nutrient dynamics in ancient oceans, and 2) applying novel isotopic systems (chromium and uranium) to ancient carbonate rocks.
My focus has been on the mid-Proterozoic Eon (ca. 1800 to 800 million years ago), wherein fundamental questions persist about the oxygen content of Earth surface environments and its relationship to the early evolution of eukaryotes. Field sites for mid-Proterozoic strata include the Vindhyan Supergroup of north-central India and the Jixian Group of north China, supplemented by drill core samples from the Atar/El Mreiti Group of Mauritania. Lately, my research has expanded to younger rocks, including the Devonian-Mississippian transition in the Appalachian Basin (eastern USA) and the late Cretaceous of the Danish Basin (northern Europe). As a NASA postdoctoral fellow at Arizona State University, I hope to constrain the prevalence of molybdenum-nitrogen co-limitation in ancient redox-stratified oceans, and use uranium isotopes to provide an unprecedented view of the redox structure of mid-Proterozoic seafloor environments.