Relative sea level history of the uppermost Cenomanian of southwestern Utah: evidence for Milankovitch−driven eustasy?

Many aspects of Late Cretaceous eustasy, including timing, amplitudes, and forcing mechanisms, remain poorly understood. Recent studies suggest a possibility of Milankovitch forcing of the Cretaceous "greenhouse" eustasy (e.g. Plint, 1991; Fischer Hinnov, 2000; Gale et al., 2002), but stratigraphic data, which would exceed, in their temporal resolution, the constraints given by biostratigraphic zonation are extremely rare. The latest Cenomanian interval of the Western Interior Seaway, which was characterized by coexistence of climate−sensitive hemipelagic rhythmites (e.g. Gilbert, 1895; Fischer, 1980) and sea−level sensitive siliciclastics (Elder et al., 1994), and is suitable for high−resolution correlations (e.g. Elder, 1985, 1991), provides an excellent opportunity to improve our understanding of climate−ocean interactions during "greenhouse" times.