Burket Shale

The Burket Shale or Geneseo Shale is the lowest member of the Harrell Shale/Genessee Group.

Burket shale
Stratigraphic range: Upper Devonian Frasnian ~383–382 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Member
Unit of	Harrell Shale, Genesee Group
Overlies	Tully Limestone
Lithology
Primary	Black shale
Other	Shale
Location
Region	New York, Ohio, Pennsylvania, West Virginia
Country	United States
Type section
Named for	Named after a small town in Blair County Pennsylvania
Named by	Charles Butts (1918)

The Burket is an organic-rich black shale that rests just above the Tully Limestone member of the Mahantango Formation. The geographical extent of the formation includes southern New York, Pennsylvania, eastern Ohio, and West Virginia. 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.^[1] 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.^[2]

Description

This organic shale is blackish gray, it may also have an olive, brown or grayish. Subsurface the bedding is massive. Where fracturing occurs Pyrite and Calcite may fill the fractures.^[3]