Paper No. 3
Presentation Time: 9:30 AM


ARMSTRONG, Ryan S., Geology and Geophysics, University of Wyoming, 471 N. 9th St., Apt. 2, Laramie, IN 82072, HOLBROOK, W. Steven, Geology and Geophysics, University of Wyoming, Laramie, WY 82071-3006, AUKEN, Esben, Aarhus University, Aarhus, 8000 and CARR, Bradley J., Department of Geology and Geophysics, University of Wyoming, Dept. 3006, 1000 University Avenue, Laramie, WY 82071,

Ground electrical resistivity data is a key tool for mapping ground water pathways and aquifers. During Spring and Summer 2103, the Wyoming Center for Environmental Hydrology and Geophysics (WyCEHG) has collected dense arrays of electrical resistivity and magnetic data by use of ground methods within watersheds in the Snowy and Laramie Ranges. In September WyCEHG will fly two 60 square km surveys of helicopter transient electromagnetic (HTEM) and aeromagnetic data within the Snowy Range and Laramie Range, Wyoming. Previous data collection will allow for a comparison of trends within shorter transects (100-200 m) to the large areas flown by HTEM, while the new airborne datasets will provide insight into aquifer properties and locations. Ground-based resistivity transects show electrically conductive zones in bedrock that presumably correspond to fluid-filled fracture zones. HTEM data will enable us to detect large-scale trends in these bedrock aquifers, which may correspond to fracture patterns visible in nearby granite outcrops. Existing magnetic data show anomalies in stream valleys, possibly due to secondary mineralization from groundwater, which also appear to be following larger structural trends within the Laramie Range. Our data will provide important insights into the viability and usefulness of airborne geophysical in studying mountain hydrology and surface/groundwater interactions in bedrock terrains.