Morgan Reed Raven

Assistant Professor

Office Location

Webb 2024


Organic Geochemistry, Geobiology


California Institute of Technology (Ph.D. 2016)        
Environmental Science and Engineering, Dept. of Geological and Environmental Sciences
Research supervisors: Alex Sessions (primary thesis advisor) and Jess Adkins
Thesis title: Organic Matter Sulfurization in the Modern Ocean

Stanford University (M.S. 2007)
Geological and Environmental Sciences
Research supervisors: Scott Fendorf (primary thesis advisor) and Dennis Bird
Thesis title: Redox Fluctuations in Cambodian Sediments: Climatic controls and effects on arsenic cycling  

Stanford University (B.A.S. 2006)        
Geological and Environmental Sciences, Political Science


Morgan is an organic geochemist and geobiologist. Since finishing her PhD at Caltech in 2016, she has been working as an Agouron Geobiology Fellow at Washington U. in St Louis. She joins the UC Santa Barbara Earth Science faculty in July 2018.

Morgan's research includes classic and emerging problems in biogeochemistry, ranging from the origins of life to modern and ancient climate change. A common thread shared by many of these questions is an under-studied role of organic sulfur. Her lab specializes in sulfur isotope analysis by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS), a powerful tool for measuring very small samples from a wide range of environments.


  • Organic matter sulfurization and enhanced carbon burialOrganic matter sulfurization and enhanced carbon burial
  • Sulfur cycling in mangrove and wetland ecosystems
  • Rates and mechanisms of organic matter transformations
  • Cryptic sulfur cycling in marine O2-deficient zones
  • Sulfur-isotope records of evolution and environment


Raven M.R., Fike D.A., Gomes M.L. "Chemical and isotopic evidence for organic matter sulfurization in redox gradients around mangrove roots." Limnology and Oceanography (in prep).?

Raven M.R., Fike D.A., Gomes M.L., Webb S.M., Bradley A.S., Owens, J.D.  "Paired organic matter and pyrite d34S records reveal mechanisms of carbon, sulfur, and iron cycle disruption during Ocean Anoxic Event 2." Earth and Planetary Science Letters (in prep).?

Raven M.R., Fike D.A., Gomes M.L., Webb S.M., Bradley A.S., McClelland H.L.O. (2018). “Organic carbon burial during OAE2 driven by changes in the locus of organic matter sulfurization.” Nature Communications (accepted, in press).    .PDF

Raven M.R., Sessions A.L., Adkins J.F., Thunell R.C. (2016). “Rapid organic matter sulfurization in sinking particles from the Cariaco Basin water column.” Geochimica et Cosmochimica Acta vol. 190, p175–190.     .PDF?

Raven M.R., Sessions A.L., Fischer W.F., Adkins J.F. (2016). “Sedimentary pyrite d34S differs from porewater sulfide in Santa Barbara Basin: Proposed role of organic sulfur.” Geochimica et Cosmochimica Acta vol. 86, p120–134.    .PDF

Raven, M.R., Adkins, J.F., Werne, J.P., Lyons, T.W. Sessions, A.L. (2015). “Sulfur-isotopic compositions of individual organic compounds from Cariaco Basin sediments.” Organic Geochemistry vol. 80, p53-59.    .PDF?

Greenwood, P., Amrani, A., Sessions, A., Raven, M.R., Grice, K. (2014). “Development and Initial Biogeochemical Applications of Compound-Specific d34S Analysis.” in Principles and Practice of Analytical Techniques in Geosciences, Royal Society of Chemistry (UK).