Late Cretaceous Uplift of Grand Canyon: Evidence From Fluid Inclusions

For over a century, the history of Grand Canyon has been of interest to many. In recent years, debates have centered around the hypothesis that Grand Canyon formed during the late Cretaceous, not the Miocene, as previously thought. In this study, fluid inclusions within carbonates from the Mauv, Redwall, Supai, and Kaibab Fms. from Grand Canyon yield entrapment temperatures between 135 and 60 °C. Comparison of these temperature to time-temperature histories based on thermochronology (U-Th/He and fission track) from nearby samples suggest that these carbonates had fluids trapped within them from 89 to 58 Ma and that major denudation of late Cretaceous strata occurred during this interval. Regionally derived burial histories and local thermochronology suggest that significant uplift of Grand Canyon and the adjacent Colorado Plateau occurred during the late Cretaceous. We interpret the timing of fluid entrapment, denudation of Cretaceous strata, and burial histories to be consistent with initial uplift associated with the early stages of formation of Grand Canyon during the late Cretaceous. Models of uplift of northern Arizona exclusively during the Cenozoic are inconsistent with these data.