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The following is a list of the mapped bedrock units in Pennsylvania . The rocks are listed in stratigraphic order. [1]
Note: Some of the Formations are laterally equivalent in age. They are listed in order from West to East in this case.
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The following is a list of the mapped bedrock units in Pennsylvania . The rocks are listed in stratigraphic order. [1]
Note: Some of the Formations are laterally equivalent in age. They are listed in order from West to East in this case.
The Silurian Shawangunk Formation is a mapped bedrock unit in eastern Pennsylvania, New Jersey, and New York. It is named for the Shawangunk Ridge for which it is the dominant rock type. The division of the Shawangunk between the Tuscarora Formation and Clinton Group has not been conclusively determined. The shift of nomenclature currently has the divide between Hawk Mountain and Lehigh Gap.
The Silurian Bloomsburg Formation is a mapped bedrock unit in Pennsylvania, New Jersey, New York and Maryland. It is named for the town of Bloomsburg, Pennsylvania in which it was first described. The Bloomsburg marked the first occurrence of red sedimentary rocks in the Appalachian Basin.
The Ordovician Martinsburg Formation (Om) is a mapped bedrock unit in Pennsylvania, New Jersey, Maryland, Virginia, and West Virginia. It is named for the town of Martinsburg, West Virginia for which it was first described. It is the dominant rock formation of the Great Appalachian Valley in New Jersey and Pennsylvania.
The Passaic Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and New York. It was previously known as the Brunswick Formation since it was first described in the vicinity of New Brunswick, New Jersey. It is now named for the city of Passaic, New Jersey, which is near where its type section was described by paleontologist Paul E. Olsen.
The Llewellyn Formation is a mapped bedrock unit in eastern Pennsylvania. It was previously known as the "coal measures" and the post-Pottsville rocks. The formation is named for the community of Llewellyn in Schuylkill County.
The Silurian Tuscarora Formation — also known as Tuscarora Sandstone or Tuscarora Quartzite — is a mapped bedrock unit in Pennsylvania, Maryland, West Virginia, and Virginia, US.
The Ordovician Juniata Formation is a mapped bedrock unit in Pennsylvania, West Virginia, Virginia, Tennessee, and Maryland. It is a relative slope-former occurring between the two prominent ridge-forming sandstone units: the Tuscarora Formation and the Bald Eagle Formation in the Appalachian Mountains.
The Ordovician Bald Eagle Formation is a mapped bedrock unit in central Pennsylvania, USA. It is a ridge-forming unit in the Appalachian Mountains.
The Ordovician Reedsville Formation is a mapped surficial bedrock unit in Pennsylvania, Maryland, Virginia, West Virginia, and Tennessee, that extends into the subsurface of Ohio. This rock is a slope-former adjacent to the prominent ridge-forming Bald Eagle sandstone unit in the Appalachian Mountains. It is often abbreviated Or on geologic maps.
Wills Creek Formation is a mapped Silurian bedrock unit in Pennsylvania, Maryland, Virginia, and West Virginia.
The Devonian Mahantango Formation is a mapped bedrock unit in Pennsylvania, West Virginia, and Maryland. It is named for the North branch of the Mahantango Creek in Perry and Juniata counties in Pennsylvania. It is a member of the Hamilton Group, along with the underlying the Marcellus Formation Shale. South of Tuscarora Mountain in south central Pennsylvania, the lower members of this unit were also mapped as the Montebello Formation. Details of the type section and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database.
The Mississippian Mauch Chunk Formation is a mapped bedrock unit in Pennsylvania, Maryland, and West Virginia. It is named for the township of Mauch Chunk, now known as borough of Jim Thorpe, Pennsylvania and for nearby Mauch Chunk Ridge where the formation crops out.
The Cambrian Chickies Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and Maryland. It is named for Chickies Rock, north of Columbia, Pennsylvania along the Susquehanna River.
The Mississippian Pocono Formation is a mapped bedrock unit in Pennsylvania, Maryland, and West Virginia, in the United States. It is also known as the Pocono Group in Maryland and West Virginia, and the upper part of the Pocono Formation is sometimes called the Burgoon Formation or Burgoon Sandstone in Pennsylvania. The Pocono is a major ridge-former In the Ridge-and-Valley Appalachians of the eastern United States
The Lock Haven Formation is a Devonian mapped bedrock unit in Pennsylvania, in the Appalachian Mountains of the United States.
Broad Top is a plateau located in south-central Pennsylvania. It extends into Huntingdon County to the north, Fulton County to the southeast, and Bedford County to the southwest. It is bounded to the west by Saxton Mountain and Terrace Mountain, and to the east by Sideling Hill. In Bedford County, Harbor Mountain forms the southern boundary. Trough Creek Valley lies between the mountains.
The Devonian Old Port Formation is a mapped bedrock unit in Pennsylvania, USA. Details of the type section and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database. Current nomenclature usage by U.S. Geological Survey restricts the name Old Port Formation to Pennsylvania, but correlative units are present in adjacent states.
The Triassic Stockton Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and New York. It is named after Stockton, New Jersey, where it was first described. It is laterally equivalent to the New Oxford Formation in the Gettysburg Basin of Pennsylvania and Maryland.
The Cambrian Warrior Formation is a mapped limestone bedrock unit in Pennsylvania.
The Gatesburg Formation is a geologic formation in Pennsylvania. It preserves fossils dating back to the Cambrian period.