Graduate Students

Grayson is investigating how microbial community makeup and habitat geochemistry influence lipid compositions, with a specific focus on bacterial bacteriohopanepolyol lipid biomarkers in hydrothermal systems around the world. For this, he extracts lipids from sediments and microbial mats and correlates the resulting abundances to concurrent geochemical and phylogenetic data. He is also working on theoretical calculations to understand how the thermodynamic properties of lipids may influence the distribution and diagenesis...

Peter focuses on reaction path modeling of high and low temperature ultramafic systems and the potential habitability and impact on known metabolic strategies from the resultant geochemistry. He also performs bioenergetic calculations regarding the chemical affinity associated with a variety of possible metabolisms in hydrothermal systems and has collected dissolved gas samples at the hyperalkaline spring systems at the Semail ophiolite for these purposes.

Juan Carlos investigates low temperature alteration of mantle peridotites mainly from the Samail ophiolite in Oman. He is using a combination of geochemical tools to constrain alteration conditions including temperature, pressure, fluid compositions paired with reaction path modeling. He is particularly interested in non-isochemical alteration and element mobility during alteration.

Libby determines rates of carbon utilization by microorganisms residing in the subsurface, especially within serpentinized fluids and serpentinizing rock-hosted microenvironments. Through this work, she seeks to describe how factors such as carbon and oxidant availability limit the extent of subsurface life.

Alta investigates the influence of geochemical gradients on microbial community composition. The geochemical gradient imposed by the mixing between serpentinization reacted water in the Semail ophiolite of Oman and surrounding surface waters provides an opportunity to find correlations between community composition and varying concentrations of methane, hydrogen, organic carbon, ammonium, sulfide, magnesium, inorganic carbon, nitrate, sulfate and varying pH, from circumneutral to hyperalkaline (pH>10).

Emily focuses on characterizing the subsurface microbial communities within the Omani serpentinizing systems. She works to collect and sequence environmental genetic material from the field to determine community structure and examine related metabolisms of the rock-microbe interactions.

Graham is a communicator of science and a geomicrobiologist. His graduate research has focused on characterizing the geochemistry and mineralogy of sulfur-rich deposits and alteration features at the Borup Fiord Pass sulfide spring system in the Canadian High Arctic. This has included detections of unexpected and rare forms of elemental sulfur (beta- and gamma-cyclooctasulfur) as well as an exotic form of hydrated sulfate carbonate (rapidcreekite) in the Borup system. Graham...

James is interested in how differences in chemical potentials (e.g. silica and aluminum activities, peridotite vs. gabbroic rocks) can influence reactions involved in the alteration of rocks rich in ferromagnesian silicates. He will use a combination of analytical and theoretical techniques to study spring and surface water samples collected from the Oman Ophiolite as well as altered rocks drilled from the Southwest Indian Ridge.

Melody investigates the influence of geological hydrogen (H2) on the activity, distribution, and diversification of H2-metabolizing organisms in high temperature hot spring environments present in Yellowstone National Park using geochemical data, microcosm-based activity experiments, and RNA analyses.

Julia is currently working on developing a technique to trace carbon cycling in methanogens using Raman spectroscopy. Her research interests include biology of extreme environments, exobiology, nutrient cycling, and microbial metabolism in serpentinite hosted ecosystems.

Hannah investigates low-temperature serpentinization in the Oman hyperalkaline aquifer and implications for microbial habitability. She is characterizing the mineralogy and oxidation state of modern serpentinized rocks in the hyperalkaline aquifer, culturing organisms from the deep subsurface, and conducting laboratory water/rock experiments probing for mechanisms behind hydrogen production at low temperatures.

Shahrzad extracts DNA from low-biomass carbonate rocks from Crystal Geyser, UT to determine the microbial community composition and metabolic processes active in the environment. Shahrzad will work on rock samples from the Lost City hydrothermal vent site in the Atlantic Ocean that will be collected in Fall 2015. Furthermore, she is isolating halophiles from two cold geysers in southern Utah based on culture-dependent studies.

Daniel investigates microbial life in hyperalkaline springs emanating from the Semail Ophiolite in Oman. He is interested in how these organisms affect water chemistry and carbon cycling in low-temperature serpentinizing systems, as well as their potential applications in toxic waste remediation and carbon sequestration.

Estafania characterizes the effect of peridotite serpentinization on important physical parameters to obtain geophysical documentation and monitoring of such processes in the subsurface. She also investigates the subsurface geology that establishes possible hydrogeological/structural networks caused by serpentinization processes by integrating a variety of geophysical methods such as Electric Resistivity Tomography (ERT), Ground Penetrating Radar (GPR), magnetic and gravity surveys with core samples and logging data from Coast Range Ophiolite Microbial...

Katie is interested in utilizing a blend of field and experimental work to study coupled Fe, N and S cycling in biologically active peridotite systems. She currently works with subsurface waters she collected from deep wells in the Oman ophiolite in January 2015.

Jeemin is interested in studying the abundance of doubly-substituted, or “clumped,” isotopologues of methane (13CH3D) and utilizing it to constrain the source of methane. Starting in Fall 2015, she will analyze geothermal fluids collected from Iceland and possibly more methane samples from other serpentinization sites.

Mary investigates the sulfur and iron geochemistry and microbial diversity within the serpentinite subsurface at the Coast Range Ophiolite Microbial Observatory in California (CROMO). She is currently creating enrichment cultures to better understand the constraints around the various Fe and S compounds that are being utilized by microbes in the system and using scanning electron microscopy to identify and analyze mineral-microbe interactions.

Alex is exploring the microbial habitats and metabolisms of serpentinizing environments. Specifically he is investigating microbe-mineral interactions, focusing on the spatial distribution of microbes and their debris in regard to their life histories and the underlying mineralogy.

Chris' research is centered around the use of bioinformatics to investigate microbial communities in their natural environment. He is currently working on a computational approach for addressing issues of contamination in environmental samples.

Chris is a geomicrobiologist with special interests in astro- and polar microbiology. His graduate research has focused on the microbial characterization and understanding of a low temperature sulfide spring system, Borup Fiord Pass, in the Canadian High Arctic. He works to determine how microorganisms play a role in sulfur cycling at such a cold and extreme locale. Chris hopes this research will help to inform how scientists might approach studying...

Lindsay is working with hydrogeologic and 16S rRNA sequence data from the Coast Range Ophiolite Microbial Observatory (CROMO) in Northern California. She is using bioinformatics in order to investigate seasonal trends in the microbial communities and compare environmental factors to the community composition. She is also working to better define the hydrogeology of the study area and determine connectivity and recharge rates within the well clusters.