Seismic Evaluation of Differential Tectonic Subsidence, Compaction, and Loading in an Interior Basin¹

Thomas H. Wilson²

©Copyright, 2000. The American Association of Petroleum Geologists. All rights reserved.
¹Manuscript received June 16, 1998; revised manuscript received June 22, 1999; final acceptance September 3, 1999.
²Department of Geology and Geography, West Virginia University, Morgantown, West Virginia 26506-6300; e-mail: [email protected]
This study was funded in part through U.S. Department of Energy contract DE-AC22-90BC14657. Comments on earlier portions of this work by Robert Milici, Robert Shumaker, Byron Kulander, Lee Avary, Kevin Biddle, and Jory Pacht were greatly appreciated. The paper also benefited from discussions with Robert Shumaker, Richard Beardsley, Joe Lemon, and Jovita Dominic. Appreciation is extended to Debbie Benson for her assistance in figure preparation. GTS Corporation provided some of the seismic data used in this study.

ABSTRACT

Quantitative analysis of depth-converted reflection times defines long-term differential motion across individual structures in a central Appalachian interior basin known as the Rome trough. Differential motion decreases exponentially with time. Rotation about a hinge defining the trough's west margin reached approximately 37% of total displacement in about 63-78 million years (m.y.). Displacement across the trough's faulted east margin occurred more rapidly and reached 37% of the total in 13-51 m.y. A major fault in the interior of the trough developed rapidly with 37% of total displacement reached in from 16 to 23 m.y. Longer term rotation across the west margin may be due to its participation in the overall subsidence of the craton during the Paleozoic. The time spanned by the formation of the East-Margin and Interior faults was restricted to the Cambrian in the northern part of the area, but to the south, movement along the East-Margin fault continued through the Middle Ordovician.