Shallow seismic investigation of surface deformation associated with the Kilmichael dome, Montgomery County, Mississippi, USA
S.D. Sloan and J.B. Harris
Journal name: Near Surface Geophysics
Issue: Vol 8, No 6, December 2010 pp. 451 - 457
Special topic: Student-based Research
Info: Article, PDF ( 7.52Mb )
Price: € 30
The Kilmichael dome structure is a circular feature exposed in unconsolidated early Tertiary sediments of north-central Mississippi, USA. The structural complexity of the area, including zones of intense faulting and uplifted strata, has led to several suggested origins for the formation of the Kilmichael dome, including meteorite impact and regional tectonics; however, the origin remains unknown. As part of an undergraduate student research project, we acquired shallow shear-wave seismic reflection data over a complex zone of surface faults on the northern flank of the Kilmichael dome, with the goal of imaging the subsurface expression of deformation associated with faulting expressed along an exposed road cut. We also collected multi-component downhole seismic data in a nearby borehole to analyse the shear-wave velocity structure of the shallow sediments and observe possible anisotropy. Polarization analysis of the downhole data identified shear-wave anisotropy consistent with structural alignments in the area. Interpretation of the reflection profile and particle motion plots from the downhole data allowed correlation with shallow structural features of the Kilmichael dome.