Research
Geologic Preservation in the Sedimentary Record
My research is about how and why information is preserved or not preserved in the geologic record. Since I read the sedimentary record as my novel of choice, I am often probing the ways in which life shows up in and influences rocks in addition to studying abiotic processes. I use field geology, petrography, trace element data, and isotopic measurements to try to determine how and why something (a body fossil, a chemical signal, a particular texture, etc.) was preserved for millions of years.
Taphonomy of Phosphatic Fossilization
For my PhD, I am studying phosphatic fossilization, a unique taphonomic mode (i.e., style of fossilization) that can preserve organisms in exceptional detail via phosphate minerals like apatite. I am currently working on the Cambrian-aged phosphatic small shelly fossils (SSFs) and archaeocyaths of southwestern Mongolia. My work aims to reconstruct the biogeochemical conditions under which these fossils formed in an effort to better understand what the presence of this style of fossilization can tell us about specific diagenetic processes, relationships between organisms, and the Cambrian earth. I have a particular interest in how biological and chemical processes within individual shell chambers may evolve a pocket of fluid that is chemically distinct from other cavities such that different parts of a single shell may experience different styles of preservation. I focus on the microscopic, using the petrographic microscope as my primary (and favorite) tool of investigation. In addition to optical microscopy and fieldwork, I have used wave-dispersive spectroscopy for elemental analysis and LA-ICPMS for trace element/REE analysis in apatite. I plan to also utilize EA-IRMS and SIMS for stable isotope geochemistry (C & O in carbonate, O in phosphate in apatite).
Records of Microbial-Metazoan Symbiosis
Symbiotic relationships between microbes and metazoans are well documented in the modern world, but evidence for symbiosis is difficult to identify in the geologic record. This is largely due to taphonomic biases and the variable preservation potential of different ecological relationships. For instance, it is much easier to preserve teeth marks on a bone than the microbiome of an animal's gut. But we know that mutualistic relationships exist between multicellular organisms and microbes by looking at modern biological processes. Can we see these relationships in the geologic record? What geochemical signatures might these relationships leave, and how would they be preserved, if at all? Because symbiosis between metazoans and phosphate-accumulating bacteria has been observed in modern ecology, I am investigating phosphatized archaeocyathids as a potential record of early microbial-metazoan symbiosis. Perhaps their style of fossilization is related to an ancient ecological relationship.