Year of Publication

2007

Document Type

Thesis

College

Arts and Sciences

Department

Geology

First Advisor

Edward W. Woolery

Abstract

Seismic reflection (P- and SH-wave), ground-penetrating radar, correlative drilling, and age dating data provide evidence of neotectonic deformation along the Caborn (CF) and Hovey Lake (HLF) faults, in the Wabash Valley fault system (WVFS). The WVFS is a series of high-angle normal faults located primarily in southern Indiana and Illinois. Since their formation, these faults have likely been transpressionally reactivated in the contemporary E-W-oriented compressive stress state. The WVFS has experienced large prehistoric earthquakes, but only moderate historic and contemporary seismicity; therefore, the seismic potential in this region is poorly defined. The bedrock expressions of the CF and HLF were imaged with seismic reflection data (P- and SH-wave). Higher resolution analyses were performed with seismic (SHwave) and ground-penetrating radar surveys to characterize structure that may extend into the overlying Quaternary sediments. Anomalous features were cored to verify structure, and to collect datable material. The CF and HLF are interpreted to extend into the uppermost five meters of sediment and to displace horizons dated to 19,740 and 31,000 years before present, respectively. Displacement along the HLF is interpreted to extend 2-3 meters above the associated age date. These structures represent the only known primary coseismic deformation of the Late Quaternary within the WVFS.

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