Dalton Hardisty and I published a diagenetic modeling paper focusing on carbonated redox proxies. We examine how different styles of diagenesis impact U isotopes, CAS isotopes, the Ce anomaly, iodine-calcium ratios, and more. Check it out (open access!) in  I was also a co-author on two other mass extinction studies! - Congrats to Terry Isson for his work on the potential for reverse weathering to prolong Early Triassic warming following the end-Permian extinction in  - Congrats to Pulkit Singh for leading an integration of paleontological and I/Ca constraints following the end-Trias ..read more

I am excited that Dr. Cole McCormick has joined our research group as a postdoctoral scholar. Cole comes to Penn State after completing his Ph.D. at the University of Manchester. He hails from Alberta, Canada, and received his B.S. and M.S. degrees from the University of Alberta. He will be leading a range of dolomite-based projects. Welcome, Cole ..read more

new paper out in Nature Geoscience End-Permian marine extinction due to temperature-driven nutrient recycling and euxinia ! We use constraints of global redox conditions (from uranium isotopes) and the spatial variability of redox (from many different types of proxies) to compare with cGENIE results. With this data-model coupling, we argue that warmer temperatures in the Early Triassic led to higher microbial respiration rates in the ocean (i.e., a stronger biological pump), which would have resulted in high amounts of nutrient recycling in the water column, sustaining anoxic conditions and po ..read more

Congrats to PhD student Fai Chanchai for successfully completing her first major milestone in her graduate degree. We're so proud of you ..read more

Pleased to share a new paper on the controls on U isotope variability in black shales, using a Miocene case study. The Monterey Formation is inherently interesting as its very phosphatic and is also the source rock for the CA petroleum industry. It also was deposited in a number of unique basins (bottom left) where U isotope behavior varied significantly. It's a complicated story, but we use U isotopes and U concentrations to try to understand the major controls (apatite concentration, basin hydrography, productivity) that drive the range in isotope values that we observe. We also show that in ..read more

Our group finished out 2021 strong! Fai, Kayla, and Kim joined NSF project collaborators on a field trip to the Death Valley region. They had a great time chatting science and seeing classic Neoproterozoic - Cambrian sections with awesome folks. Chelsie, Kaitlin, and Kim went to AGU in New Orleans. Congrats on some great presentations ..read more