My research is focused on water-rock interaction as recorded in a planet's near-surface environment. I use both experimental methods (laboratory and analogue studies) and observational methods (rover and orbital data analysis) to quantitatively address geologic questions on Earth, Mars, and smaller rocky and icy bodies. Descriptions of my past and ongoing projects can be found below.
Continuous flow chemistry
Adapting a method developed for pharmaceutical synthesis, we are using continuous flow laboratory equipment to constrain the details of chemical reactions occurring during water-rock interaction. Specifically, we are interested in cation mobilization in martian groundwater, and organic mobility in simulated Ceres subsurface conditions. I am Co-I on this grant.
Experimental constraints on groundwater-driven redox gradients on Mars
I am using abiotic laboratory sediment columns to simulate the ancient Mars subsurface and identify specific conditions where groundwater redox gradients can be developed. I am Science PI on this research grant hosted in JPL's Origins and Habitability Lab.
The effect of temperature and relative humidity on mineral spectra
I am interested in how changes in temperature and relative humidity affect the VNIR spectra of Mars-relevant hydrous minerals, especially phyllosilicates and Mg sulfates. Using a small atmospheric chamber attached to an FTIR spectrometer, I studied how quickly these minerals can uptake and lose water from their crystal structure. Notably, I found that the spectral evidence of dehydrated Mg sulfates is easily obscured if clay minerals are present in the same sample. This has important implications for planning the Curiosity rover's upcoming traverse route.
Chemostratigraphy of Mt. Sharp
Using new statistical analyses, I am looking at how co-movement of elements and geological indicators through time can inform our understanding of water conditions in Gale crater.
Mineralogy and stratigraphy of Mt. Sharp
Using CRISM images processed using a new technique by our coauthors, I revisited parts of Mt. Sharp other than the Curiosity rover traverse to understand how mineralogy changes across morphological contacts. These stratigraphic relationships and how they vary laterally can help constrain the crater's history, both during its lacustrine phase and long after. I am continuing this work as a MSL Participating Scientist.
Lake Towuti: a terrestrial analogue for Lake Gale?
Lake Towuti is a redox-stratified lake in ultramafic bedrock in Indonesia. This provides a rare opportunity to test the hypothesis that Lake Gale was redox-stratified. I characterized the crystalline and amorphous mineralogy of the catchment, lake basin, and a 100 m long drill core to understand what signals can be uniquely linked to lake conditions. I found that amorphous Fe-rich phases are created rapidly in the water column, and that they persist in ~1 million year old sediment.
Diamond color origin using FTIR and Raman spectroscopy
Spectroscopy is a main tool to investigate whether diamonds are natural, lab-grown, and/or have had their color enhanced. My expertise at the Gemological Institute of America was in spectral analysis of very small gems, or melee. I developed new analytical techniques for quickly determining the mineralogy and color origin of melee using FTIR spectroscopy, publishing results and methods in Gems & Gemology.
Biomarkers and rapid heating experiments
Methylphenanthrenes are organic molecules that can be used as a paleothermometer to understand past fault slip rates. We calibrated this technique using fault samples with pseudotachylite, a visible record of the most intensely heated part of the rock. To understand the kinetics of these reactions we also conducted rapid heating experiments to see how the molecules broke down under different time and temperature regimes.