Wills Creek Formation is a mapped Silurian bedrock unit in Pennsylvania, Maryland, Virginia, and West Virginia.
The Hamilton Group is a Devonian-age geological group which is located in the Appalachian region of the United States. It is present in New York, Pennsylvania, Maryland, Ohio, West Virginia, northwestern Virginia and Ontario, Canada, and is mainly composed of marine shale with some sandstone.
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 Pennsylvanian Pottsville Formation is a mapped bedrock unit in Pennsylvania, western Maryland, West Virginia, Ohio, and Alabama. It is a major ridge-former in the Ridge-and-Valley Appalachians of the eastern United States. The Pottsville Formation is conspicuous at many sites along the Allegheny Front, the eastern escarpment of the Allegheny or Appalachian Plateau.
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 Hinton Formation is a geologic formation in West Virginia. It preserves fossils dating back to the Carboniferous period. It is mainly made up of limestone, sandstone, and shale.
The Waynesburg Formation is a coal, sandstone, and siltstone geologic formation in West Virginia and Pennsylvania. It preserves fossils dating back to the Permian period.
The Frederick Limestone is a geologic formation in Maryland and Virginia. It preserves fossils dating back to the Cambrian period.
The Rockdale Run Formation is a geologic formation in Maryland, Pennsylvania, Virginia and West Virginia. It preserves fossils dating back to the Ordovician period.
The Bowen Formation is an Ordovician-age geological formation in the Appalachian region of the eastern United States. It occupies a thin stratigraphic range between the Wardell and Witten formations in some areas of southwest Virginia and northeast Tennessee. It is particularly well-exposed in Tazewell County, Virginia. Unlike its encompassing strata, the Bowen Formation is mostly calcareous sandstone and mudrock rather than limestone. The thicker upper part of the formation is composed of layered red mudrock which is replete with mudcracks. The thinner lower part, which is not always preserved, is a coarser unit of dark grey stratified sandstone which weathers to a rusty-brown color. Fossils are rare, restricted to stromatolites and Tetradium fibratum.
The Java Formation is a geologic formation in Kentucky, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia. It preserves fossils dating back to the Devonian period. The formation comprises the Pipe Creek Shale, Wiscoy Sandstone Member in New York, and Hanover Shale Member except in Tennessee.
The Tomstown Dolomite or Tomstown Formation is a geologic formation in Maryland, Pennsylvania, Virginia and West Virginia. It preserves fossils dating to the Cambrian Period.
The Lithograph City Formation is a geologic formation in Iowa, part of the Cedar Valley Group. It preserves fossils dating back to the Devonian period. The formation is composed of dolomite and limestone, with many fossils and vugs in the lower part, while the upper part contains few fossils.
The Troublesome Formation is a geologic formation in Colorado. It preserves fossils dating back to the Neogene period. It consists of Pale shades of pink, tan, gray, green, and white interbedded siltstone and mudstone, less abundant arkosic sandstone and conglomerate, and sparse limestone and altered crystal-vitric ash and tuff; generally poorly consolidated. It includes atypical deposits containing abundant pink, granitic cobbles and boulders along the western parts of the outcrop in the west-central and southwestern parts of the Granby Quadrangle, Fossil mammals from three sites indicate a late Oligocene age.
The Blairmore Group, originally named the Blairmore Formation, is a geologic unit of Early Cretaceous age in the Western Canada Sedimentary Basin that is present in southwestern Alberta and southeastern British Columbia. It is subdivided into four formations: Cadomin Formation, Gladstone, Beaver Mines and Ma Butte, all of which are defined by type sections, most of which contain plant fossils. In some areas the Blairmore contains significant reservoirs of natural gas.
The Mount Whyte Formation is a stratigraphic unit that is present on the western edge of the Western Canada Sedimentary Basin in the southern Canadian Rockies and the adjacent southwestern Alberta plains. It was deposited during Middle Cambrian time and consists of shale interbedded with other siliciclastic rock types and limestones. It was named for Mount Whyte in Banff National Park by Charles Doolittle Walcott, the discoverer of the Burgess shale fossils, and it includes several genera of fossil trilobites.
The Staffin Bay Formation is a geologic formation in Scotland. It preserves fossils dating back to the Callovian of the Middle Jurassic. It consists of two members, the lower Upper Ostrea Member, which consists of dark grey, fissile mudstone with a shelly limestone bed, and laminated and rippled sandstones. While the upper Belemnite Sands Member consists of medium-grained calcareous sandstones and siltstones
The Waynesboro Formation is a limestone, dolomite, and sandstone geologic formation in Virginia, Maryland, Pennsylvania and West Virginia. In some areas it is composed of limestone and dolomite. The Waynsboro Formation is one of the formations that make up the Shenandoah Valley. It dates back to the Cambrian period and is not considered fossiliferous.
The Princeton Sandstone is a geologic formation in West Virginia. It preserves fossils dating back to the Carboniferous period.
The Huntersville Chert or Huntersville Formation is a Devonian geologic formation in the Appalachian region of the United States. It is primarily composed of mottled white, yellow, and dark grey chert, and is separated from the underlying Oriskany Sandstone by an unconformity. The Huntersville Chert is laterally equivalent to the Needmore Shale, which lies north of the New River. It is also laterally equivalent to a sandy limestone unit which is often equated with the Onondaga Limestone. to the west and the Needmore Shale to the east. These formations are placed in the Onesquethaw Stage of Appalachian chronostratigraphy, roughly equivalent to the Emsian and Eifelian stages of the broader Devonian system.
West Virginia, 
Pennsylvania, 
Virginia, 
Maryland 
