Identifying Possible Pre-Chattanooga Structures in the Cumberland Plateau of Kentucky and Tennessee Using Trend-Surface Residual Anomaly Maps

Evenick, Jonathan C. and Robert D. Hatcher, Jr.
University of Tennessee, Department of Earth and Planetary Sciences, Knoxville, TN

New maps have been constructed for the Cumberland Plateau of Kentucky and Tennessee to investigate the possibility of Pre-Chattanooga structures in the Ordovician rocks beneath the Plateau. The main horizons mapped include the tops of the Nashville (Trenton/Lexington), Stones River (Black River/High Bridge), and Knox Groups along with the Chattanooga Shale and the Millbrig (Mud Cave) and Deicke (Pencil Cave) bentonites. Other mapped units include the Wells Creek Dolomite, Copper Ridge Dolomite, Conasauga Group, Rome Formation, and top of basement, although limited data in the region limit the usefulness of these maps. Overall, trend-surface residual anomaly (TSRA) maps are a more accurate mapping technique/filter that enables subtle structures to be more accurately identified. The TSRA maps were constructed from standard structure contour maps and 1st- and 2nd-order trend surfaces. The maps identify numerous isolated small-scale structures across the Cumberland Plateau (that are probably not connected) that could be targets for future exploration. The western Valley and Ridge of Tennessee (west of the Whiteoak Mountain-Clinchport thrust) should also be explored further. We have shown that the existing Rose Hill and Swan Creek fields are producing from Ordovician reservoirs that have identical geophysical well log signatures as those subsurface Nashville-Stones River units beneath the Cumberland Plateau.

AAPG Search and Discovery Article #90031©2004 AAPG Eastern Section Meeting, Columbus, Ohio, October 3-5, 2004