Allegheny Formation facts for kids
Quick facts for kids Allegheny FormationStratigraphic range: Pennsylvanian |
|
|---|---|
| Type | Sedimentary |
| Underlies | Conemaugh Group |
| Overlies | Kanawha Formation and Pottsville Formation |
| Lithology | |
| Primary | Sandstone, coal |
| Location | |
| Region | Appalachian Mountains |
| Country | United States |
| Extent | Pennsylvania, Maryland, West Virginia, Ohio |
| Type section | |
| Named by | H. D. Rogers, 1840 |
The Pennsylvanian Allegheny Formation is a mapped bedrock unit in western and central Pennsylvania, western Maryland and West Virginia, and southeastern Ohio. It is a major coal-bearing unit in the Appalachian Plateau of the eastern United States.
Description
In Pennsylvania, the Allegheny Formation includes rocks from the base of the Brooksville Coal to the top of the Upper Freeport Coal, and was defined to include all economically significant coals in the upper Pennsylvanian sequence. The formation consists of cyclothemic sequences of coal, shale, limestone, sandstone, and clay. It contains six major coal zones, which, in stratigraphic order, are:
- Upper Freeport Coal
- Lower Freeport Coal
- Upper Kittanning Coal
- Middle Kittanning Coal
- Lower Kittanning Coal
- Brookville Coal
Members
Glen Richey (PA), Laurel Run (PA), Mineral Springs (PA), Millstone Run (PA), Clearfield Creek (PA); Clarion (OH, MD, PA, WV), Kittanning (PA), Freeport (PA, MD, OH, WV); Putnam Hill (OH, PA); Vanport (PA, MD, OH, WV); Butler (MD, PA), Worthington (MD, PA); Washingtonville (OH, PA, WV), Columbiana (OH)
Age
Relative age dating of the Allegheny places it in the middle Pennsylvanian period.
