RUI: Alpine Loess, Periglacial Uplands, and Exotic Additions: Investigating Past and Present Dust Deposition in the Alpine Zone of the Uinta Mountains, Utah

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A non-technical description of the project, which explains the project's significance and importanceAtmospheric dust is generated in lowlands through a variety of natural and human-induced processes. Once delivered to high mountain environments, wind-borne dust is responsible for a multitude of effects including altering the pH and chemistry of surface water, contributing to soil formation, and decreasing the reflective properties of snow. In the Rocky Mountains, recent study of lake sediment records suggests that rates of dust deposition have increased in the past few centuries, linking human land use in lowland basins with dust deposition in the mountains. This project will analyze the amount and distribution of dust accumulating in the Uinta Mountains to determine the regional and inter-annual variability in dust deposition rates and properties. Cores from alpine lakes will also be investigated to ascertain the changes in wind-borne deposits over the last several thousand years as continental glaciers receded and human habitation increased. Given the growing evidence that dust deposition plays an important role in the ecology of alpine systems, this project will provide useful information for management of mountain ecosystems and the surrounding basins. This project will be conducted at a primarily undergraduate institution and will train the next generation of research scientists.A technical description of the projectThis project will use an extensive set of existing lake-sediment cores and soils data, along with new collections of dust and soil, to test three complementary hypotheses: 1) Dust flux and geochemical properties are primarily controlled by aridity within regional source areas in the western United States; 2) Post-glacial sedimentary records from high-elevation lakes in the Uintas will record synchronous changes in physical properties that reflect variations in the regional dust system driven by paleoclimate variability; 3) Long-term (~106 - 107yrs) weathering on the unglaciated Uinta summit upland has resulted in the formation of pedogenic clays from elemental building blocks delivered by atmospheric dust. Six undergraduate students will receive training in research techniques and each will complete independent research along with the opportunity to present at professional meetings.