Current Research Late-Quaternary Glacial and Paleoclimate History of the Uinta Mountains, Northeastern Utah A 3-year NSF-funded project Ben Laabs, Brad Singer, Dave Mickelson (UW-Madison) and Jeff Munroe (Middlebury College) received funding for this project in 2004. The goals are built upon previous work done in the Uintas by Munroe and Laabs and will substantially increase knowledge on the timing and pattern of glaciation in the Uinta Mountains as a whole. Specific objectives are: Use air photograph and 1:24,000-scale field mapping to determine the extent of glaciers during and since the LGM in the southern Uinta Mountains. Much of the range has already been mapped at this scale (Munroe, 2001; ongoing geologic mapping) and continued mapping will provide the basis for subsequent glacier and paleoclimate reconstructions. Use concentrations of cosmogenic Be-10 and Al-26 in moraine boulders to calculate surface-exposure ages that will provide estimates of the timing of the LGM in the Uinta Mountains. This dating method has been applied to several mountain ranges in the western U.S., including the Wind River Range (Gosse et al., 1995a; Chadwick et al., 1997; Phillips et al., 1997) and Yellowstone Plateau (Licciardi et al., 2001), both of which are near the Uintas (Fig. 1). Cosmogenic surface-exposure dating is the only method available to obtain numerical age estimates of LGM-age deposits in the Uintas, as preservation of organic material in terrestrial deposits for radiocarbon dating is not common in these mountains. Constrain the age of deglaciation and possible latest Pleistocene glacial readvance through coring of high-elevation tarns in headwater basins. Previous studies of the glacial record in the Rocky Mountains have focused primarily on determining the timing of the local LGM (e.g., Phillips et al., 1997); comparatively little research has been done to determine the timing of the last deglaciation and the dynamics of alpine glaciers during this important climatic transition (e.g., Madole, 1980). Set limits on paleoclimate conditions during the LGM in the Uintas. Glaciers are sensitive recorders of local climate change and their former extent can be used to estimate deviations in temperature and precipitation from modern values. Recently developed numerical models will be used to simulate glacier mass/energy balance and ice flow during the LGM in the Uintas. Click here for an update on the status of Ben Laabs' work in the southern Uintas. Upper Provo River Drainage Kurt Refsnider began work in the Upper Provo River drainage in the summer of 2004 and will continue in the summer of 2005. The goals for this project have been formulated to address new aspects of the glacial geology of the Uinta Mountains and provide additional data to similar ongoing studies in the area. Specific goals are: Map the surficial geology of a portion of the upper Provo River watershed Use cosmogenic dating techniques to establish an age for the large moraine near the end of the North Fork Provo drainage Estimate the rate of erosion of the Uinta Mountain Group bedrock due to glacial processes during the Smiths Fork (Pinedale equivalent) glaciation using a two-nuclide cosmogenic isotope technique Calculate equilibrium line altitudes (ELA) for the paleoglaciers in the upper Provo River drainage and estimate mean annual temperature and precipitation at the LGM