Structurally Deformed Late Ordovician to Early Silurian Strata in North-Central Kentucky and Southeastern Indiana
Amidst the vast expanse of horizontally disposed Paleozoic strata in the Interior Lowlands, structurally deformed early Paleozoic beds are exposed in certain tributaries of the Ohio River. The deformation ranges from weak folding to overthrusting. The Brassfield Limestone of Early Silurian age contains breccia of earlier age. The Brassfield Limestone itself is brecciated in the region of structural disturbance. The structural disturbance and the brecciation, though of different ages, appear to be associated with probable periodic upheavals of the Cincinnati Arch during Llandoverian (Early Silurian) to Wenlockian (Middle Silurian) times.