Paper No. 10
Presentation Time: 8:00 AM-12:00 PM
AN INTEGRATED EXPLORATION MODEL FOR DUSEL SITE CHARACTERIZATION AT THE KIMBALLTON MINE, GILES COUNTY ,VIRGINIA
Geotechnical site characterization for the Kimballton Dusel site has proceeded along the lines of a major mineral or oil and gas exploration project. 100K digital geologic mapping (Bartholomew and others, 2000) was checked using original field compilation sheets. Detailed stratigraphy from USGS and VDMR publications was inserted into published cross sections resulting in selection of a model published by Gray and Woodward (Woodward, 1985) as the simplest solution that honored both the available seismic profiles and the detailed bedrock mapping. A series of 2D cross sections prepared using actual stratigraphic thicknesses following the architecture of the Gray Woodward model were digitized and converted to 3d models by Jason Shelton and Steve Miller in the VT College of Engineering. 3d models were used to locate proposed exploration bore holes and seismic profiles along the crest of Butt Mountain above the proposed lab site. Seismic profiling to test the 3d model was conducted during the summer of 2004 by J.A. Hole and M.G. Imhoff of the VT Geosciences Dept. Strike and dip lines appeared to confirm the general multithrust architecture noted by Demoracki and others in the Bane Dome area to the SW. Restored cross sections indicate at least 50 % shortening by imbrication of massive Cambro-Ordovician carbonate units in the subsurface. An additional 20 % of shortening was recognized due to multiple detachment and thrust stacking in the midlevel decollement resulting in three-fold thickened Martinsburg Formation sections measured on the mountain slopes above the lab site. Detailed sections of the highly deformed Ordovician metapelites and carbonates first described by Rick Law of Virginia Tech confirm the style of deformation recognized in seismic sections and cross sections. Slaty cleavage formation and extensive recrystallization are also confirmed by elevated seismic velocities and densities measured from the Reedsville-Trenton rocks within the Martinsburg section.