The Burket Shale is the lowest member of the Harrell Shale/ Genessee Group. The Burket is an organic-rich black shale that rests just above the Tully Limestone member of the

Mahantango Formation The Devonian Mahantango Formation is a mapped bedrock unit in Pennsylvania, West Virginia, and Maryland. It is named for the North branch of the Mahantango Creek in Perry and Juniata counties in Pennsylvania. It is a member of the Hamilton Gro ...

. The geographical extent of the formation includes southern

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

, eastern

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

, and

West Virginia West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the Bur ...

. The Burket is also known as the Geneseo in New York and parts of Northern Pennsylvania. In 1918 the Burket and Harrell were described by Charles Butts, from outcrops located in Blair County, located in southwestern Pennsylvania.Butts, Charles, 1918, Geologic section of Blair and Huntingdon Counties, central Pennsylvania:

American Journal of Science The ''American Journal of Science'' (''AJS'') is the United States of America's longest-running scientific journal, having been published continuously since its conception in 1818 by Professor Benjamin Silliman, who edited and financed it himself ...

, 4th series, v. 46, p. 523-537. In 1920, C. H. Chadwick described the Genesee and Geneseo formations in New York. The usage of the different names is just a matter of personal preference.

References

{{Stratigraphic column of West Virginia Shale formations of the United States Devonian System of North America Devonian Pennsylvania Devonian Ohio Devonian West Virginia