Abstract

Present structure of the Cumberland Plateau results from two components: (1) regional eastward dip of about 25 feet per mile off the Cincinnati arch; and (2) Pine Mountain, Cumberland Plateau, and Sequatchie Valley bedding thrusts, which strike north-eastward and have roots in the Valley and Ridge province to the southeast.

Gentle eastward dip off the flank of the Cincinnati arch is the only structure affecting the undisturbed portion of the plateau, and is also the primary component of structure in the faulted area. Bedding thrusts do not disturb the position and attitude of strata within the thrust sheets. Locally, however, where the faults cut across bedding, superficial anticlines are formed. The structural concordance between the undisturbed areas and areas of bedding thrusts supports the “no-basement” interpretation for the essential regional structure.

Movement of the Cumberland Plateau overthrust sheet over steep portions of its generally flat fault plane caused superficial flat-topped, steep-sided anticlines similar to the Powell Valley anticline of the Pine Mountain overthrust. Abrupt ends of such anticlines mark places where buried steep thrusts become buried strike-slip faults.

The oldest thrust is the northwest-dipping Whetstone Mountain fault; next is the Cumberland Plateau overthrust; the youngest thrusts are the Seauatchie Valley thrust and some faults of the Valley and Ridge province.

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