Devonian Extinctions!

Black shales feature prominently in the Paleozoic strata of the Appalachian Basin, especially of Late Devonian age. The widespread deposition of these organic-rich rocks suggests that anoxia or even euxinia - a sulfidic water column - was rather extensive during this period. Further, the black shale layers coincide with a number of mass extinction events. Broadly, I (and many colleagues!) have worked to understand the spatial and temporal extent of oxygen stress in this region and relate it to potential extinction magnitude. I integrate both geochemical (organic and inorganic) and paleontological methods to try to better understand the paleo-redox history of these black shales and the microbial communities that thrived in these ancient waters.

Hangenberg mass extinction microbial community dynamics: https://doi.org/10.1111/gbi.12314

Frasnian-Famennian high/low lattitude lipid biomarker comparisons: https://doi.org/10.1016/j.orggeochem.2016.05.007

Prolonged oxygen stress in the Appalachians during the Devonian: https://doi.org/10.1016/j.palaeo.2021.110226