Greenhouse climates, mass extinctions, and paleoceanography using integrated paleontological, geochemical, and sedimentological observations

My research efforts center on determining changes in water column structure and circulation patterns and how they relate to climate evolution, carbon cycling, and the distribution of organisms during transitions into and out of ancient greenhouse climates as well as other intervals of global change. Much of my group’s primary data are generated in the stable isotope lab at the University of Missouri that Dr. Cheryl Kelley and I oversee. In addition to specific projects on the Cretaceous/Paleogene and Permo-Triassic boundaries, my current major research themes include:

1) Investigating past ocean circulation patterns using a collaborative, two pronged observational (Nd isotopic ratios in fish debris, oxygen and carbon isotopes in foraminifera) and modeling approach with an emphasis on the waning of the Cretaceous greenhouse climate.

2) Constraining temperature evolution of the Cretaceous greenhouse climate focusing on oxygen isotopic studies of exceptionally well preserved calcareous microfossils. Samples collected during an upcoming IODP Expedition (fall of 2017) should advance investigation of both temperature and circulation history of the Cretaceous.

3) Documenting Ordovician temperature history using oxygen isotopic studies of phosphate-oxygen in conodonts.