Bald Eagle Valley - Geology

Geology

Bald Eagle Valley is in the western part of the Ridge and Valley province of the Appalachian Mountains. During the Appalachian orogeny, sedimentary rock layers on the supercontinent of Pangaea were folded, forming a huge mountain range. The Nittany Arch was an ancient Himalayan scale mountain that once towered above what is now the adjacent Nittany Valley.

The oldest rock layers from deep within the eroded mountain are now exposed on the east side of the Bald Eagle ridge. Younger rocks from the outer layers of the arch are exposed in the Bald Eagle Valley, with the youngest at the foot of the Allegheny Front. The rock layers in the valley were folded from horizontal to almost vertical, and now read like pages in a geologic history book covering the entire Devonian period. The vertical attitude of the rocks also contributes to the straightness of the valley.

Erosion resistant Silurian Tuscarora Formation Quartzite left the Bald Eagle ridge standing above the valley. The Bald Eagle Creek runs at the foot of the ridge on a bed of Devonian Hamilton Group Shale. Durable Lock Haven Formation Mudstone forms a parallel series of steep elongated knolls running west of the flood plain, some almost as high as the ridge. Catskill Formation Sandstone underlies a series of lower gently rolling hills at the foot of the plateau, which is in turn formed from uplifted Mississippian Sandstone.

See also: Geology of Bald Eagle Mountain

Coordinates: 41°00′N 77°45′W / 41.0°N 77.75°W / 41.0; -77.75