For the past several years I have been working with my colleague Henry Fricke (Colorado College) on an NSF-funded collaborative project investigating carbon and oxygen isotope ratios of vertebrate fossil remains from the Late Cretaceous of North America. The goal is to reconstruct aspects of terrestrial ecology, hydrology, and climate using isotopic data. Because interpretations of isotopic data can be somewhat ambiguous in the absence of contextual information (e.g., accurate facies associations), detailed stratigraphic, sedimentological, and taphonomic analyses of sampled localities were conducted. My major emphasis was the characterization of the diagenetic histories of the vertebrate fossils under study. To this end, my students and I, along with Henry and Alan Koenig of the USGS (Denver), have analyzed hundreds of fossil bones and teeth from microfossil bonebeds in the Two Medicine and Judith River Formations in order to characterize (1) authigenic cementation histories, and (2) REE patterns (using LA-ICP-MS). To date five students (Chris Dwyer, Josephine Williams, Cara Harwood, Robin Canavan, Rachel Murray) have completed senior theses related to this research (see student research page for more information).

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