Character of rigid boundaries and internal deformation of the southern Appalachian foreland fold-thrust belt
Hatcher RD, Lemiszki PJ, Whisner JB. 2007. Character of rigid boundaries and internal deformation of the southern Appalachian foreland fold-thrust belt. Geological Society of America Special Papers. (433):243-276
The deformed wedge of Paleozoic sedimentary rocks in the southern Appalachian foreland fold-thrust belt is defined by the configurations of the undeformed basement surface below and the base of the Blue Ridge–Piedmont megathrust sheet above, together with the topographic free surface above the thrust belt. The base of the Blue Ridge-Piedmont sheet and underformed basement surface have been contoured using industry, academic, and U.S. and state geological survey seismic-reflection and surface geologic data. These data reveal that the basement surface dips gently SE in the Tennessee embayment from Virginia to Georgia, and it contains several previously unrecognized normal faults and an increase in dip on the basement surface, which produces a topographic gradient. The basement surface is broken by many normal faults beneath the exposed southern Appalachian foreland fold-thrust belt in western Georgia and the Carolinas. Our reconstructions indicate that small-displacement normal faults form beheaded basins over which thrust sheets were not deflected, where-as large-displacement normal faults (e.g., Tusquitee fault) localized regional facies changes in the early Paleozoic section and major Alleghanian (Permian) structures. These basement structures correlate with major changes in southern Appalachian foreland fold-thrust belt structural style from Virginia to Alabama.
- Type
- Journal Article
- Authors
- Hatcher, Robert; Lemiszki, Peter; Whisner, Jennifer
- Units
- BLRI , GRSM
- Keywords
- Appalachians, Faults, Geology, seismic-reflection