Sunbury shale

Figure 8. Generalized cross-section from southern Kentucky to northern Ohio showing the abnormal thickness of Sunbury shale as recorded by drillers—after Pepper (25).

Ells, G. D., "Stratigraphic Cross Sections Extending From Devonian Antrim Shale to Mississippian Sunbury Shale in the Michigan Basin," U.S. DOE Report No. FE-2346-30, 1978. 

Van Beuren, V. V., "The Sunbury Shale of the Central Appalachian Basin — A Depositional Model for Black Basinal Shales (Abstract Only), in Prior, W., et al.f Eds., Energy Resources of Devonian-Mississippian Shales of Eastern Kentucky, Annual Field Conference April 9-11, 1981, Kentucky Geological Survey, Lexington, 1981. 

In eastern Kentucky the Ohio Shale terminology has been used where the Mississippian Sunbury Shale and the underlying Bedford Shale can still be recognized. A typical stratigraphic section with carbon distribution is shown in Figure 3. Typically the overburden is a mixture of claystone and siltstone in the Borden Formation. This unit directly overlies the Sunbury Shale which is a black, laminated, siliceous shale rich in organic matter with some pyrite. The Sunbury thins to the south from 20-25 feet in Lewis County to four feet in Estill County. 

SUNBURY SHALE. Finely laminated black shale with small intervals of brownish-black 13.3-18.U thick in cores. Common pyrite bands and nodules, sparsely fossiliferous. 

The two defined economic zones (Sunbury Shale and the HGZ of the Cleveland Member) are separated by interburden units of the Bedford Shale throughout the study area and the Berea Sandstone in Lewis County. Thickness histograms of the economic zones and their associated interburden units are presented in Figure 4, which shows that the Sunbury Shale decreases in thickness to the south while the Cleveland HGZ remains fairly constant at 25-30 thick. The Bedford and Berea decrease in thickness rapidly toward the south with less than a foot of interburden separating the two economic zones in Montgomery County. 

Figure 4, Cross-section of the thicknesses of the stratigraphic units above the base of the Cleveland HGZ (top), and variation in hydrogen and carbon for the Sunbury shale and Cleveland HGZ in eastern Kentucky (bottom).

Sunbury Shale Cleveland Total Shale HGZ Huron Shale Sunbury Shale Cleveland Total Shale HGZ Huron Shale... 

Figure 5. Plot of Fischer assay yields and carbon content for D series oil shales. Regression data are Sunbury Shale, oil yield - 1.03 (%C) - 0.69 (r =. 97) and Cleveland Shale, oil yield- 1.18 (%C) - 1.16 (r =. 97).

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