| Antrim Shale | |
|---|---|
| Stratigraphic range: Late Devonian | |
 Antrim Shale outcrop and productive gas area, from Ryder (1996) US Geological Survey. | |
| Type | Formation |
| Sub-units | Upper Member, Lachine Member, Paxton Member, and Norwood Member |
| Underlies | Bedford Shale, Ellsworth Shale, and Sunbury Shale |
| Overlies | Squaw Bay Limestone, Traverse Formation and Milwaukee Formation |
| Location | |
| Region | Midwestern United States |
| Country | United States |
| Extent | Indiana, Michigan, Ohio, and Wisconsin |
| Type section | |
| Named for | Antrim County, Michigan |
The Antrim Shale is a formation of Upper Devonian age in the Michigan Basin, in the US state of Michigan, and extending into Ohio, Indiana and Wisconsin. It is a major source of natural gas in the northern part of the basin.
The Antrim Shale was defined by A. C. Lane in 1901, and named for type-section exposures in Antrim County, Michigan. The formation was previously known as the St. Cleric Shale in Michigan, and the Genesee Shale in Indiana.[1]
- ^ Indiana Geological Survey, Antrim Shale, accessed 4 November 2009.