The Allegheny Formation makes up the base of the three local formations. It can be found along the Kiskiminetas River. The two defining characteristics of the formation are the Upper Freeport sandstone and shale, and the Upper Freeport coal bed. Mining of the Upper Freeport Coal is one of the reasons for mine subsidence locally. It is one of the largest coal seams locally.

Examples of Upper Freeport Sandstone along PA 66, a half mile from Parks Township.

Formation Stratigraphy

Allegheny Formation

Formations Above the Allegheny Formation

Above the formation sits the entire Conemaugh Group. The group divides into two formations, the Glenshaw Formation directly above the Allegheny, and the Casselman Formation above the Glenshaw.

More about the Allegheny Formation Online