Research Interests:

  • Geobiology of extreme environments including the deep subsurface, hydrothermal systems, ultrabasic/acidic systems, and caves
  • Compound-specific isotope organic geochemistry (H, C, S) applied to microbial ecology, biogeochemical cycling in microbe-rich environments, and the sedimentary record of environmental perturbation
  • Neoproterozoic chemical evolution of the ocean-atmosphere system during extreme isotope excursions
  • Carbonate sedimentology, stratigraphy, and geochemistry with an emphasis on microbialite preservation and morphology


  • 2013            Ph.D. Geobiology, California Institute of Technology, Division of Geological and Planetary Science

Thesis: Isotopic proxies for microbial and environmental change: Insights from hydrogen isotopes and the Ediacaran Khufai Formation
Advisors: Alex Sessions and John Grotzinger

  • 2008            M.S. Geobiology, California Institute of Technology, Division of Geological and Planetary Science
  • 2007            B.A. summa cum laude, Earth & Planetary Sciences, Environmental Studies, Washington University in St. Louis

Awards and Honors:

  • 2017               Packard Fellowship Award
  • 2013               Dean’s Award, Recognition of Service to Graduate Honor Counsel, Caltech
  • 2013               Dean’s Award, Recognition of Service to Graduate Student Counsel, Caltech
  • 2012               Student poster award, 2nd place, Gordon Conference on Organic Geochemistry
  • 2012               AAPG Student Oral Awards Competition, 2nd place, American Association of Petroleum Geologists Annual meeting
  • 2012               BASIN Student Registration Grant for the Fall AGU Meeting
  • 2007               The Ernest L. Ohle, Jr. Prize, Department of Earth and Planetary Science, Washington University

Research Grants:

  • 2018-2021      NASA Exobiology – Biosignature Preservation in Sulfate-Dominated Hypersaline Environments
  • 2017-2022      Packard – Illuminating microbial dark matter using subterranean geomicrobiology
  • 2017-2020      NASA PSTAR – Biologic and Resource Analog Investigations in Low Light Environments (BRAILLE)
  • 2015-2018      NASA Exobiology – Lipid Biomarkers of the Deep Subsurface Biosphere
  • 2015-2017      NASA Astrobiology Institute – Life Underground
  • 2015-2016      Institute for Sustainability and Energy at Northwestern University – Biomarker Records of Arctic Climate Change
  • 2009-2012      National Science Foundation Graduate Research Fellowship
  • 2007-2008      Gordon and Virginia Eaton Fellowship, California Institute of Technology
  • 2006               Research Scholarship in Environmental Studies, Washington University
  • 2005               Hoopes Research Fellowship, Washington University

Research Experience:

  • Characterization of the type, scope, and energetic requirements of the continental deep subsurface biosphere using field and lab measurements of geochemistry, DNA sequencing, cultivation of microbes, and geochemical modeling (J. Amend)
  • Assessing biological fractionation of hydrogen isotopes by anaerobic bacteria using culturing techniques, compound-specific hydrogen isotope measurements, and modeling of cellular hydrogen flow (A. Sessions)
  • Characterization of lipid content, D/H, and community composition of a range of hydrothermal mat types to compare proxies and test correlation of D/H with microbial metabolism (A. Sessions, J. Spear)
  • Characterization of the Neoproterozoic Khufai Formation using sequence stratigraphy, facies analysis, carbon and oxygen isotopes, and sulfur isotopes and concentration to constrain the depositional conditions at the onset of the Shuram excursion and understand changes in Ediacaran biogeochemical cycles(J. Grotzinger, T. Lyons)
  • Isolation and characterization of novel hyperthermophiles from Yellowstone National Park using hot-spring specific geochemical measurements to inform growth media composition (J. Amend, D. Meyer-Dombard)
  • Analysis of microbial populations using molecular biological methods in arsenic-rich hydrothermal sediments in Papua New Guinea and acid-sulfate hydrothermal systems in Yellowstone National Park (J. Amend, D. Meyer-Dombard)

Selected Field Experience:

  • Sept 2018: Sample collection and geochemical characterization of hypersaline lakes in British Columbia with Alex Pontefract and Chris Carr.
  • Aug-Sept 2018: Sample collection at Lava Beds National Monument in Lava Caves for the BRAILLE project
  • Oct-Feb 2013-2014: Subsurface sample collecting trips to the SURF laboratory in the former Homestake Mine for initial fields site characterization and geobiological research.
  • Jan-Mar 2009-2012: Four to seven week field seasons in Oman characterizing the Neoproterozoic Khufai Formation including: measuring stratigraphic sections, collecting samples for chemostratigraphy, and analyzing stratigraphic relationships.
  • Mar 2011: Carbonate Stratigraphy field course, Permian Reef in the Guadalupe Mountains (J. Grotzinger)
  • Mar 2009: Modern Carbonate Sedimentology field course, Lee Stocking Island, Bahamas (J. Grotzinger)
  • July 2008, 2009: Sample collection and geochemical characterization of hydrothermal microbial mats from Yellowstone National Park, USA (A. Sessions, John Spear)
  • July 2007: Geochemical and microbial sampling of shallow submarine hydrothermal vents in the Aeolian Islands, Italy (J. Amend, D. Meyer-Dombard, R. Summons, E. Shock)
  • June-July 2006: Six weeks in Montana and Wyoming as part of YBRA geology field camp
  • June-July 1999-2006: Field cartography assistant and geochemistry technician for Group Exploring Organic Processes in Geochemistry (GEOPIG), School of Earth and Space Exploration, Arizona State University (E. Shock)
  • June 2004, 2005: Geologic Mapping Field Assistant, New Mexico State Mapping Project New Mexico Bureau of Geology and Mineral Resources (G. Osburn, S. Kelley)

Twitter: @ProfMaggie