The work that goes on in my lab encompasses a wide spectrum of topics but aims to ultimately connect geochemical cycles, budgets and fluxes through the modern and ancient.

Much of my research involves studies of biogenic material fluxes to the sea floor and across this boundary. Capturing fluxes through the water column involves the use of sediment traps and measurements of water column profiles (solutes and suspended particles) and modeling; fluxes across the sea floor involves the use of benthic chambers and pore water diagenetic models. Analysis of the solid phase helps link oceanographic biogeochemistry with the sedimentary rock record. Fluxes and reactions involving O, C, N, P, CaCO3, bSi, Fe and S (and their isotopes) are among those that I work on. Most of my students have an opportunity to join an oceanographic research cruise and/or participate in various forms of field research. Recent field study areas include: Eastern Tropical North and South Pacific Ocean; Western Tropical North Atlantic Ocean within the Amazon River plume; Eastern North Pacific (between Hawaii and Alaska); Gulf of Mexico zone of hypoxia; San Pedro/Santa Monica Basin OMZ; Yellowstone National Park Hot Springs; Mono Lake, CA; Monterey Formation, CA; Green River Formation, WY and the T-J boundary rocks (Pucara Group) in central Peru. Some research details are provided on the sidebar links.

I am affiliated with many groups at USC including the Geobiology, Geochemistry and Climate programs in Earth Sciences, Marine Environmental Biology; Molecular Biology; Environmental Studies Program, Physics and Engineering Groups. I also am affiliated with the Wrigley Institute for Environmental Studies.

My lab combines standard geologic and inorganic chemical analytical facilities with some novel geochemical instrumentation including: gas separation high vacuum lines, GC’s, NOx Analyzer, Membrane Inlet Mass Spectrometer, microfluidics experimental systems, micro-electrodes, a benchtop environmental SEM with EDS, and several Picarro C isotope CRDS analyzers.

I teach graduate courses in carbonate chemistry and sedimentology, marine sedimentary geochemistry and seminars in geobiology and geochemistry.

I helped initiate and have been a director of the International GeoBiology Summer Course (2002-2009) and remain involved with this training course, one that has had a profound impact on the growth and development of this field. I was chairman of the Earth Sciences Department from 2012-2018.