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Study of the interaction between uplift and erosion is a major theme of our science, but our understanding of their interplay is often limited by a lack of quantitative data. A classic example is the Colorado Plateau, for which the starting and ending points are well known: The region was at sea level in the Late Cretaceous, and now, the deeply eroded land surface is at ~2 km. The path of the landscape between these endpoints is less clear, and there has been longstanding debate on the mechanisms, amounts, and timing of uplift and erosion. We use a geographic information system to map, interpolate, and calculate the Cenozoic rock uplift and erosional exhumation of the Colorado Plateau and gain insight into its landscape...
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Middle and late Holocene paleoclimate can be inferred from lake-level fluctuations recorded in the sediment of two, fresh, ground-water?controlled paleolakes in Lake Canyon, southeast Utah. The record from Lake Canyon contributes proxy climate data for the region as well as insight into climate controls on sedimentation. The paleolakes were formed immediately upcanyon of side-stream confluences where disproportionately large volumes of alluvium were focused into the bedrock canyon. Excellent exposure allows a depositional facies model to be developed and allostratigraphic units to be defined. A facies-based proxy for the past shoreline position is applied to the allostratigraphy and radiocarbon-based chronostratigraphy...
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As in many areas of high relief, debris flows are an important process linkage between hillslopes and the Green River in the canyons of the eastern Uinta Mountains, yet the physical conditions that lead to debris flow initiation are unknown. A recent episode of enhanced debris-flow and wildfire activity provided an opportunity to examine the geomorphic impact of fire and the processes by which weathered bedrock is transported to the Green River. Field investigations and analysis of elevation and precipitation data were undertaken in 15 catchments with recent debris flows to determine how surficial geology, wildfire, topography, bedrock strength, and meteorology influence hillslope processes. The recent debris flows...
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