Union Furnace Quarry, Huntingdon County

Union Furnace quarry, located in Huntingdon County about 13 miles northeast of Altoona. View of the eastern highwall of the east quarry, from the top of the highwall. The Black River Group limestones are dipping approximately 65 degrees toward the north-northwest in an open, asymmetric structure known as the Scotch Valley syncline. This syncline is plunging to the north-northeast at about 13 degrees. A field trip guidebook on the Trenton and Black River carbonates provides a detailed review of these rocks in central Pennsylvania..

--Photo by John A. Harper, 2003