Sunbury Shale (MIDMs;0)

State	Michigan
Name	Sunbury Shale
Geologic age	Mississippian-Devonian
Original map label	DMs
Comments	Age is listed as "unassigned" on map, but is placed between Mississippian and Devonian on stratigraphic section . Secondary unit description from USGS Geologic Names lexicon (ref. MI016): Sunbury Shale is the youngest of the regionally extensive black gas shales. It is typically fissile black shale that weathers into small discoidal sharp-edged chips. Pyrite is common, particularly near the base where it separates a zone of small inarticulate brachiopods and SIPHONODELLA conodont fauna from the underlying Berea. Unit is present only in the western part of the basin. Crops out at many places along the eastern flank of the Cincinnati arch in OH and northeastern KY and ranges there from 10 to 40 ft thick. Thins to a featheredge toward the east. Overlies the Berea throughout eastern OH, WV, and northern KY, but overlies the Cleveland Member of the Ohio Shale in central KY. Grades laterally into the upper unit of the Gassaway Member of the Chattanooga Shale in south-central KY and is present only as a biostratigraphic zone in the top of the Gassaway in north-central TN.
Primary rock type	black shale
Secondary rock type
Other rock types
Lithologic constituents	Major Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)
Map references	Milstein, Randall L. (compiler), 1987, Bedrock geology of southern Michigan: Geological Survey Division, Michigan Dept. of Natural Resources, scale= 1:500,000
Unit references	Milstein, Randall L. (compiler), 1987, Bedrock geology of southern Michigan: Geological Survey Division, Michigan Dept. of Natural Resources, scale= 1:500,000 USGS Geologic Names Lexicon (GEOLEX) [http://ngmdb.usgs.gov/Geolex/]
Geographic coverage	Alcona - Huron - Lenawee - Livingston - Macomb - Montmorency - Oakland - Oscoda - Saint Clair - Sanilac - Washtenaw - Wayne