Cenozoic Landscape Evolution of the Grand Canyon Region, Arizona

Abstract

The landscape evolution of the southwestern Colorado Plateau has eluded accurate description due to the scarcity of a Cenozoic rock record. However, advances in low-temperature thermochronology have shown the ability to quantitatively assess erosion patterns by recording the thermal history of rocks in the subsurface. This study utilizes apatite (U-Th)/He and fission track analysis of a several newly collected datasets to constrain the unroofing of the Grand Canyon region. Assessment of topographic evolution of the Kaibab Uplift is accomplished through 3-dimensional thermokinetic modeling of real and synthetic erosion and landscape evolution scenarios. Results illustrate the sensitivity of low-temperature thermochronometric ages to topography and also provide constraints on the erosion history atop the Kaibab Uplift. Investigation of a lateral transect outlines the regional unroofing patterns throughout the Grand Canyon region and support conclusions from assessment of additional vertical transects and borehole data.