Kentucky has been disturbed by two major catastrophic events. The major portion of the state was upheaved to what is referred to as the Cincinnati Anticline, and erosion has resulted in forming of several physiographic regions, four of which will be traversed on this trip--namely, the Inner Blue Grass region, the Outer Blue Grass region, the Knobs, and the Eastern Coal Fields. The second major catastrophic event was the Appalachian folding, of which the Pine Mountain Overthrust and its faulting affects the southeastern Kentucky area.
The Inner Blue Grass region contains the lowest exposed geologic formation in Kentucky which is the Middle Ordovician exposed in the bluffs of the Kentucky River at Clays Ferry. The limestones of the Middle Ordovician are major sources of the quarry industry, which provides aggregates for the concrete and roadbuilding industries. Rocks of Upper Ordovician, Silurian, and Devonian ages, are exposed in the Outer Blue Grass. The transition from the Outer Blue Grass into the Knobs region can be recognized by a strata of black shale having considerable thickness.
The Knobs region is a ring of hills, mainly exposing Mississippian age materials. This ring is a relatively narrow band compared to the other three major regions.
The Eastern Coal Field is of the Pennsylvanian era and contains numerous coal seams varing widely in thickness. Most of these coal beds have been commercially exploited by tunneling and strip mining methods. Evidence of old strip mining activities can be seen on the upper slopes of the hills starting midway between London and Barbourville. The strip mining activities became more prominent nearer Pineville.
Included herein is a continuous road log of exposed geologic formations visible in roadway cuts and outcrops. Distinctive formations are located by the distance in miles from the starting point. An overall, brief, stratigraphic outline is presented to show the general geological relationships and a detailed columnar section of each of the major physiographic regions is shown.
Digital Object Identifier
Southgate, Herbert F.; Hopkins, Tommy C.; and Scott, Gordon D., "Selected Features of Kentucky Geology from Lexington to Pineville" (1969). Kentucky Transportation Center Research Report. 1166.