Seminar Series – Dr. Jeff Catalano: The Hidden Lives of Iron Minerals

Dr. Jeff Catalano, Washington University in St. Louis

The Hidden Lives of Iron Minerals: Trace Element Fate During Dynamic Surface Transformation

Natural environments host an array of chemical compounds that enhance the reactivity of iron oxide minerals, natural forms of rust widespread in soils, sediments, and rocks. Iron oxides coexist with soluble, reduced iron at redox interfaces, such as groundwater springs and seeps, the rhizospheres of wetland plants, hyporheic zones in riparian systems, and redoximorphic soils. Biogeochemical processes in more oxic environments, in including many soils and aquatic sediments, often generate reactive organic acids. This talk examines the dynamic surface transformations of iron oxide minerals that occur in environments hosting mineral-reactive solutes. Such mineral transformations are largely hidden from view, often producing no observable signature in iron chemistry or mineralogy. However, these subtle processes substantially alter the fate of trace metal contaminants and micronutrients and modify elemental and isotopic proxies in the rock record. 

Host: Xiaoming Liu