High-precision U/Pb dating of the Cenomanian-Turonian boundary Kaiparowits Plateau, Utah

Abstract

The massive marine species turnover at the Cenomanian-Turonian boundary is associated with Oceanic Anoxic Event 11 (OAE II) and is often identified by an increase of a13C in the carbon isotopic record. A high-precision chronology of the Cenomanian- Turonian boundary is needed to better constrain the cause, timing, and extent of OAE II. To create such a timeline, four bentonite samples from the Kaiparowits Plateau, Utah were dated using U/Pb geochronology. The Cenomanian-Turonian boundary is constrained to be 94.040 ± 0.029/0.098/0.14 Ma, in agreement with recent astrochronologic studies of the same time period. This research will help improve the calibration of the astronomical time scale, as well as provide a greater understanding of the Cretaceous environment..