Investigating the Origins of Clays in Alpine Soils in the Uinta Mountains, Utah

Studying clay in soils is an important approach to understanding long-term processes of chemical weathering. Previous work in the Uinta Mountains of northeastern Utah has revealed much about the dust that is transported into... [ view full abstract ]

Studying clay in soils is an important approach to understanding long-term processes of chemical weathering. Previous work in the Uinta Mountains of northeastern Utah has revealed much about the dust that is transported into this area, but little work has been completed on the clays in Uinta soils.  The upper elevations of the Uintas were not glaciated during the last Ice Age, meaning that alpine soils have been undisturbed for an unusually long period of time.  Furthermore, the Uinta bedrock is primarily quartz-rich sandstone that does not inherently contain the building blocks of clay minerals; and yet clays are abundant in these soils.  The central purpose to this study, therefore, is to determine if these clays were produced through long-term weathering of the quartzose sandstone bedrock combined with dust deposition, or if the clays are older remnants from a warmer weathering regime that existed prior to the Ice Age.  In July 2016 a set of 18 clay-rich samples was collected from the ridge line above Chepeta Lake.  These samples will be analyzed using loss on ignition, X-ray diffraction, and X-ray fluorescence to elucidate the origin and significance of the clays in these soils.