New “Reflections” on Existing Seismic-Data Interpretations of the Cambrian and Precambrian near a Carbon Sequestration Test Well in Hancock County, Kentucky

James A. Drahovzal
Kentucky Geological Survey, University of Kentucky, Lexington, KY 40506, [email protected]

New 2D reflection seismic data were acquired in Hancock County, Kentucky, to support a carbon sequestration test well to be drilled in 2009 by the Kentucky Consortium for Carbon Storage (www.kyccs.org). The data confirm much of earlier seismic interpretations in the area, but reveal some previously unknown aspects. First, the distribution of the Mount Simon Sandstone is now interpreted to be discontinuous and likely thin or absent in the test well. Second, the earlier interpretation of three distinct Precambrian reflector packages based on sparse existing seismic data was confirmed by the new data. The sequence, lying directly below the Precambrian unconformity, is a nearly conformable, largely undeformed, probable siliciclastic sequence with mounded reflectors, possibly derived from erosion of the Louisville Uplift. This sequence onlaps onto an underlying second northeast-dipping, highly reflective package of unknown origin. The second sequence sharply truncates the underlying third, very thick reflector package that, because it is marked by numerous internal truncations, has been interpreted as a fold and thrust belt. The fold and thrust character of this sequence was previously confirmed by data from southern Indiana that show a marked east-vergent fold and thrust belt called the Hoosier Thrust Belt. The new data confirm the character of the three sequences but show north-verging thrust faults in the deepest sequence. The drilling of the well will test the presence of the Mount Simon Sandstone and the siliciclastic nature of the shallowest Precambrian sequence, but fuller regional interpretation of the deeper thrusted sequence must await further data.

AAPG Search and Discovery Article #90095©2009 AAPG Eastern Section Meeting, Evansville, Indiana, September 20-22, 2009