Alex L. Sessions
Nico and Marilyn van Wingen Professor of Geobiology
B.A., Williams College, 1991; M.Sc., Dartmouth College, 1996; Ph.D., Indiana University, Bloomington, 2001. Assistant Professor, Caltech, 2003-10; Associate Professor, 2010; Professor, 2010-23; van Wingen Professor, 2023-.
Research Overview
Professor Sessions focuses on hydrogen and carbon isotopic studies of organic geochemistry and microbial biogeochemistry, with an emphasis on natural microbial processes regulating the production and preservation of marine and sedimentary organic matter. Also the development of new stable-isotopic methods for investigating complex organic materials and microbial ecosystems.
Research Summary:
hydrogen and carbon isotopic studies of organic geochemistry, microbial biogeochemistry
Publications
- He, Juan;Sessions, Alex L. et al. (2025) Sea surface water isotope changes recorded by alkenone δ²H from the northern South China Sea over the last 260 kyrsGlobal and Planetary Change
- Chimiak, L.;Hara, E. et al. (2024) Glycine synthesis from nitrate and glyoxylate mediated by ferroan brucite: An integrated pathway for prebiotic amine synthesisProceedings of the National Academy of Sciences
- Mueller, Elliott P.;Panehal, Juliann et al. (2024) Isotopic evidence of acetate turnover in Precambrian continental fracture fluidsNature Communications
- Xie, Hao;Formolo, Michael J. et al. (2024) Theoretical and experimental constraints on hydrogen isotope equilibrium in C1-C5 alkanesGeochimica et Cosmochimica Acta
- Silverman, Shaelyn N.;Wijker, Reto S. et al. (2024) Biosynthetic and catabolic pathways control amino acid δ²H values in aerobic heterotrophsFrontiers in Microbiology
- Crémière, Antoine;Tino, Christopher J. et al. (2024) A volatile sulfur sink aids in reconciling the sulfur isotope mass balance of closed basin lakesGeochimica et Cosmochimica Acta
- Csernica, Timothy;Sessions, Alex L. et al. (2023) High-dimensional isotomics, part 2: Observations of over 100 constraints on methionine's isotomeChemical Geology
- Weiss, Gabriella M.;Sessions, Alex L. et al. (2023) Analysis of intramolecular carbon isotope distributions in alanine by electrospray ionization Orbitrap mass spectrometryInternational Journal of Mass Spectrometry
- Zeichner, Sarah S.;Chimiak, Laura et al. (2023) Position-specific carbon isotopes of Murchison amino acids elucidate extraterrestrial abiotic organic synthesis networksGeochimica et Cosmochimica Acta
- Mueller, Elliott P.;Wu, Fenfang et al. (2022) Quantifying Isotopologue Reaction Networks (QIRN): A modelling tool for predicting stable isotope fractionations in complex networksChemical Geology