Dr. Julien T. Middleton

Julien T. Middleton is currently a postdoc at the University of California – Santa Barbara. Their work uses non-traditional stable isotope measurements to interrogate biogeochemical processes from the basin to the micron scale, with an interest in bridging the gap between isotope signatures in the modern ocean and large-scale microbial cycling. To understand the relationship between microbially-produced isotope signatures and sedimented climate records, the first line of action must be a rigorous understanding of diagenetic alteration. Significant work is necessary to validate several biologically essential isotope records: in particular, some mineral records are susceptible to isotopically-fractionating ion exchange, a process that allows cation exchange between a mineral lattice and fluid while at chemical equilibrium and may overwrite the isotopic record of interest. To this end, their current research is focused on combining in situ observations, controlled laboratory experiments, and detailed modeling to investigate the potential effects of isotopically-fractionating ion exchange in the sediments and water column.