Postdoctoral Scholar

  • Christy Grettenberger – characterizing a new Cyanbacterial group, the Aurora, as well as characterizing Melainabacteria from microbial mats in Lake Vanda, Antarctica. Christy is also leading a Biological Integration Institute planning grant on the origin of photosynthesis.

Graduate Students

  • Jessica Mizzi (Microbiology) – understanding the organism that produces O2 oases in Lake Fryxell, Antarctica
  • Emilia Hernandez (Geology) – understanding iron and sulfide cycling in Neoarchean environments and Lake Fryxell, Antarctica
  • Sydney Salley (Geology) – understanding nutrient cycling in Antarctic microbial mats with an emphasis on diffusion processes; applying insights to Neoarchean microbial communities

Undergraduate Students

  • Angela Micheletti – Archean microbialites
  • Maggie Duran – Soil crusts
  • Ana Menchaca – Discussions with the lab group


Postdoctoral Scholars

  • Marion Nachon – Sedimentology and diagenesis of sedimentary rocks in Gale Crater, Mars
  • Bekah Shepard
  • Ryoji Shiraki

Graduate Students

  • Megan Dillon – Currently a postdoctoral scholar at Lawrence Berkeley National Labs.
    • Ph.D., 2018. The Phylogenetic and Metabolic Structure of the Benthic Microbial Mats in Lake Fryxell, Antarctica: Effects of Photosynthetically Active Radiation and Oxygen Concentration.
  • Frances Rivera-Hernandez – Currently a post doctoral scholar at Dartmouth University.
    • Ph.D. 2018. Establishing Diagnostic Criteria for Identifying Ancient Perennially Ice-Covered Lakes in the Sedimentary Record of Earth and Mars.
  • Tyler Mackey – Currently a postdoctoral scholar at MIT; Agouron Geobiology Fellowship recipient.
    • Ph.D. 2016. Sand, Mud, and Calcite: Microbial Landscapes on Antarctic Lake Beds.
    • M.S. 2012. Initiation of branched growth in conoform stromatolites as a response to microbial community and water depth changes in Lake Joyce, Antarctica.
  • Marisol Juarez Rivera – Currently a Ph.D. student at ASU.
    • M.S. 2016. Recreating Microbial Ecosystems at the Dawn of the Great Oxidation Event.
  • Amy Williams – Currently an Assistant Professor at University of Florida.
    • Ph.D. 2014. Microbial Biosignature Preservation at Iron Mountain, California.
  • Cara Harwood (Theisen) – Worked at UCDavis to promote excellence in teaching for several years.  Currently working as Director of Professional Development in Teaching and Learning at WISCIENCE, University of Wisconsin-Madison.
    • Ph.D. 2013. Microbial and Metazoan Influences on Microbialite Growth Structures: Insights from Recent Lacustrine Microbialites in Pavilion Lake, BC, and Cambrian Thrombolites from the Great Basin, CA and NV.
    • M.S. 2009. Multiple Origins of Diverse Microbial Fabrics in Co-occurring Thrombolitic and Stromatolitic Structures from the Neoproterozoic Beck Spring Dolomite.
  • Bekah Shepard
    • Ph.D. 2009. The Significance of Cell Motility to Microbial Community Morphogenesis.
  • James Bishop – Currently working as a geologist at Chevron.
    • Ph.D. 2008. Sedimentation and Diagenesis During the Late Paleozoic Ice Age: Arrow Canyon, Nevada, and the Capitan Backreef, Slaughter Canyon, New Mexico.
    • M.S. 2004. A New Model for Molar Tooth Structure, Facies, and Stratigraphy of the Neoarchean Monteville Formation, Transvaal Supergroup, South Africa.
  • Greg Chavdarian – Worked in the petroleum industry for several years. Currently working as an environmental tour guide and freelance drone videographer.
    • M.S. 2008. Polygonal Cracks and Mineral-Atmospheric Water Cycling in Hydrous Sulfate Sands: An Analog to Martian Outcrops.
  • Nic Huerta – Completed a M.S.E. in petroleum engineering and Ph.D. in geology at the University of Texas, Austin, and is now working as a geologist at the DOE National Energy Technology Laboratory.
    • M.S. 2007. Neutron Computed Tomography and Porosity in Geologically Relevant Samples.
  • Murphy, Megan – Worked as a geologist at Chevron for several years.
    • Ph.D. 2006. Variations in Microbialite Morphology with Depositional Environment in a Precambrian Ramp Deposit, Hamersley Group, Western Australia.
  • Maris Tabor
    • M.S. 2004. Applications of Neutron Computed Tomography for 3-D Imaging of Microbial Structures in Archean Carbonates.
  • Kat Perkins – Currently working as an academic advisor at a community college.
    • M.S. 2003. Sequence Stratigraphy of a Portion of the Lower Cambrian Grand Cycle C, Southwestern Nevada and Southeastern California.
  • Nat Stephens – Currently working as a Senior Geologist at ExxonMobil Exploration Company.
    • Ph.D. 2002. Late Devonian Stratigraphy, Stable Isotopic Analyses, and Paleoecology in the Napier, Oscar, and Emanuel Ranges, Canning Basin, Western Australia.
  • Sarah Tourre – Worked in environmental consulting.
    • M.S. 2000. Cave-Filling Herringbone Calcite: Morphology and Geochemistry of an Unusual Carbonate Cement from Egypt.

Undergraduate Students (incomplete list)

  • Caleb Dumlao, 2018-2019 – characterizing water characteristics in Spring Creek Reservoir, Iron Mountain, CA
  • Brian Troupin 2018-2019 – looking for magnetotactic bacteria
  • Emma Hoffman-Davies, 2019. Causes for the Formation of Ordovician Thrombolites in the Hueco Mountains, Texas, USA
  • Sramek, Natasha, 2018. Quantifying pinnacle morphology using 3-dimensional reconstructions of microbial mats in Lake Vanda, Antarctica.
  • Liedman, Sasha, 2014. GIS Analysis of the Water Balance of Lake Vanda, Antarctica. Currently a graduate student at Rutgers University.
  • Juarez Rivera, Marisol, 2013. Unraveling the three dimensional morphology of Archean microbialites. Completed a M.S. at UC Davis. Currently a graduate student at Arizona State University.
  • Dolezal, Lauren, 2009. 2D and 3D Analysis of Thrombolites: Stromatolite Diagenesis or Originally Clotted Texture.
  • Stevens, Eric, 2009. Microbialites in 2D and 3D. Completed a M.S. at University of Minnesota.
  • Stork, Natalie, 2008. CaCO3 Precipitation in Freshwater Biofilms Dominated by Oscillatoria sp. Completed a M.S. at University of Connecticut. Currently working in the environmental consulting industry.
  • Senge, Patrick, B. S. 2006. Development of the Late Archean Microbialite Support and Drape Structures of the Gamohaan Formation, Transvaal Supergroup, South Africa. Currently working in the mining industry.
  • Chavdarian, Gregory V., B.S. 2005. Cracks and Razorbacks: Pieces of Mars at White Sands National Monument, New Mexico. Completed a M.S. in Geology with Sumner in 2008. Currently working as an environmental tour guide.
  • Alexander, Kathryn, B.S. 2005. “MISS” in a Laboratory Setting: Observations and Mechanisms of Formation. Completed a M.S. in Geobiology at Arizona State University.
  • Huerta, Nicolas, B.S. 2003. Neutron Computed Tomography: A Characterization of the System at McClellan Nuclear Radiation Center and Presentation of Groundwork Research for Use by Sedimentary Geologists. Completed a M.S. in Geology with Sumner in 2007, a M.S.E. in petroleum engineering and Ph.D. in geology at the University of Texas, Austin, and is now working as a geologist at the DOE National Energy Technology Laboratory.
  • Lee, Gina, B.S. 2003. Thirty-nine Years of Cache Creek Migration and Embankment Erosion. Completed a M.S. at San Francisco State University after working as an environmental consultant.
  • Snyder, Jason, B.S. 2002. Isotope Geochemistry of Egyptian Cave Deposits. Completed a M.S. in Atmospheric Sciences and a Ph.D. in Geography at UC Davis.
  • Fenger, Tracy L., B.S. 2000. Glacial Interpretation for the Rainstorm Member of the Johnnie Formation, Eastern California. Completed a M.S. in Paleoclimatology at University of North Carolina, Chapel Hill, after working as an environmental consultant.