The top of the Upper Freeport coal bed marks the contact between the Allegheny Formation (Middle Pennsylvanian) and the Conemaugh Formation (Upper Pennsylvanian) at their type area in western Pennsylvania. The position of the Upper Freeport is uncertain in the tri-state area of Ohio, Kentucky, and West Virginia because of lack of continuity and apparent miscorrelations of coal beds. Our stratigraphic analysis of coal-bed correlations with respect to our identification of the Brush Creek Limestone Member, the lowest marine member of the Conemaugh Formation, indicates probable miscorrelations of coal beds by previous workers in this area. In Lawrence County, Ohio, Condit identified the Mahoning coal bed as 46 ft below the Brush Creek Limestone and 24 ft above the Upper Freeport coal bed. Northward along the Ohio River in southeastern Ohio, the Brush Creek Limestone-Mahoning interval is about 30 ft. Wanless correlated the Princess 9 coal bed of Kentucky with the Upper Freeport of Ohio and Pennsylvania. Huddle et al indicated that in eastern Kentucky the Princess 9 is in the Conemaugh Formation, about 45 ft below the Cambridge Limestone Member (correlated with the Brush Creek Limestone Member) and about 35 ft above the Upper Freeport. Thus, the Mahoning coal bed of Ohio appears to correlate with three units in eastern Kentucky—the Princess 9 of Huddle et al, the uppermost Princess 9 of Connor and Flores, and the Brush Creek coal bed of Sharps—and with the Brush Creek coal bed in parts of the adjoining areas of West Virginia. This stratigraphic analysis indicates that the true Brush Creek Limestone-Upper Freeport interval is about 70-110 ft in the tri-state area, which is consistent with the same stratigraphic interval to the north.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.