HR: 14:55h
AN: S53C-06    [Abstracts]
TI: Geophysical and Geological Evidence of Neotectonic Deformation Along the Hovey Lake Fault, Lower Wabash Valley Fault System, Central United States
AU: * Woolery, E W
EM: woolery@uky.edu
AF: University of Kentucky, Dept. of Geological Sciences 101 Slone Building, Lexington, KY 40506 United States
AU: Rutledge, F A
EM: frutledg@vt.edu
AF: Virginia Polytechnic Institute, 19 Patton Hall, Blacksburg, VA 24060 United States
AU: Wang, Z
EM: zmwang@uky.edu
AF: University of Kentucky, Kentucky Geological Survey 228 MMRB, Lexington, KY 40506 United States
AB: High-resolution seismic (shear-wave) reflection profiles were collected over a segment of the Hovey Lake fault, a known Paleozoic fault within a system of faults in the southernmost Wabash River valley of the central United States. Although the system of faults, called the Wabash Valley fault system, lie in an area of recognized prehistoric and contemporary seismicity, their seismogenic potential remain poorly defined, however. Consequently, the objectives of this study were to assess the Hovey Lake fault, one of the more prominent fault strands in the system, for neotectonic reactivation, and if present, collect sediment samples for dateable material from the disrupted horizons to provide an age constraint for the movement. The resultant stacked profiles show high-angle deformation extending above the Paleozoic bedrock, and into Upper Quaternary sediment. Time displacement calculations from the data show approximately 10.5 m of offset on the top-of-bedrock horizon, and 2 m of inverted displacement along the earliest-arriving Quaternary soil reflector at a depth of 5 m. Preliminary correlative coring found organic material in a disrupted soil horizon located 7.7 m below ground surface. Subsequent carbon-14 testing of the deeper horizon allows us to place a maximum age constraint at this site of approximately 37,000 YBP.
DE: 7230 Seismicity and seismotectonics
DE: 8010 Fractures and faults
SC: Seismology [S]
MN: 2004 AGU Fall Meeting