The geology of the Appalachians dates back more than 1.1 billion years to the Mesoproterozoic era when two continental cratons collided to form the supercontinent Rodinia, 500 million years prior to the development of the range during the formation of Pangea. The rocks exposed in today's Appalachian Mountains reveal elongate belts of folded and thrust faulted marine sedimentary rocks, volcanic rocks and slivers of ancient ocean floor—strong evidences that these rocks were deformed during plate collision. The birth of the Appalachian ranges marks the first of several mountain building plate collisions that culminated in the construction of Pangea with the Appalachians and neighboring Anti-Atlas mountains near the center. These mountain ranges likely once reached elevations similar to those of the Alps and the Rocky Mountains before they were eroded.
The Monongahela River, sometimes referred to locally as the Mon, is a 130-mile-long (210 km) river on the Allegheny Plateau in north-central West Virginia and Southwestern Pennsylvania. The river flows from the confluence of its west and east forks in north-central West Virginia northeasterly into southwestern Pennsylvania, then northerly to Pittsburgh and its confluence with the Allegheny River to form the Ohio River. The river includes a series of locks and dams that makes it navigable.
John James Stevenson was an American geologist, born in New York City. He graduated from New York University in 1863, became professor of chemistry at West Virginia University for two years (1869–71), then served as professor of geology at New York University until 1909. During 1873–74 and from 1878 to 1880 he was geologist for the United States Geological Survey. He also served on the Pennsylvania Geological Survey from 1875 to 1878 and from 1881 to 1882. He was president of the Geological Society of America in 1898.
The Permian Dunkard Group (Pd) is an area of rock, Early Permian in age, in the south of Ohio, southwestern Pennsylvania, West Virginia and the hilltops of the Georges Creek Basin of Maryland. In Ohio, it is found primarily in Washington County. It is notable for being one of the few areas of Permian sediment east of the Mississippi River. In addition, it is the youngest surface rock in the state of Ohio.
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 Marcellus Formation or the Marcellus Shale is a Middle Devonian age unit of sedimentary rock found in eastern North America. Named for a distinctive outcrop near the village of Marcellus, New York, in the United States, it extends throughout much of the Appalachian Basin.
The Virgilian series is the youngest part of the Pennsylvanian epoch in the North American geologic classification series. During Virgilian times, the top of the Conemaugh and the entire Monongahela group were deposited. As with other Carboniferous series, it comprises cyclothems, or distinct cycles of sedimentary rock formation.
The Bedford Shale is a shale geologic formation in the states of Ohio, Michigan, Pennsylvania, Kentucky, West Virginia, and Virginia in the United States.
The Allegheny Group, often termed the Allegheny Formation, is a Pennsylvanian-age geological unit in the Appalachian Plateau. It is a major coal-bearing unit in the eastern United States, extending through western and central Pennsylvania, western Maryland and West Virginia, and southeastern Ohio. Fossils of fishes such as Bandringa are known from the Kittaning Formation, which is part of the Allegheny Group.
Megamolgophis is an extinct genus of eel-like tetrapod, possibly belonging to the group Lysorophia. Fossils from this genus have been found in the Allegheny mountains of the eastern United States. The genus is endemic to geological formations of this area, such as the Greene and Washington formations of the Early Permian Dunkard Group, as well as the Pennsylvanian Conemaugh Group.
The Pittsburgh coal seam is the thickest and most extensive coal bed in the Appalachian Basin; hence, it is the most economically important coal bed in the eastern United States. The Upper Pennsylvanian Pittsburgh coal bed of the Monongahela Group is extensive and continuous, extending over 11,000 mi2 through 53 counties. It extends from Allegany County, Maryland to Belmont County, Ohio and from Allegheny County, Pennsylvania southwest to Putnam County, West Virginia.
The Casselman Formation mapped sedimentary bedrock unit in Pennsylvania, Maryland, and West Virginia, of Pennsylvanian age. It is the uppermost of two formations in the Conemaugh Group, the lower being the Glenshaw Formation. The boundary between these two units is the top of the marine Ames Limestone. The Conemaugh Group overlies the Upper Freeport coal bed of the Allegheny Formation and underlies the Pittsburgh coal seam of the Monongahela Group.
In lithostratigraphy, coal measures are coal-bearing strata, with the term typically applied to European units of the Upper Carboniferous System.
The Glenshaw Formation is a mapped sedimentary bedrock unit in Pennsylvania, Maryland, West Virginia, and Ohio, of Pennsylvanian age. It is the lower of two formations in the Conemaugh Group, the upper being the Casselman Formation. The boundary between these two units is the top of the marine Ames Limestone. The Conemaugh Group overlies the Upper Freeport coal bed of the Allegheny Formation and underlies the Pittsburgh coal seam of the Monongahela Group.
Paleontology in West Virginia refers to paleontological research occurring within or conducted by people from the U.S. state of West Virginia. West Virginia's fossil record begins in the Cambrian. From that time through the rest of the early Paleozoic, the state was at least partially submerged under a shallow sea. The Paleozoic seas of West Virginia were home to creatures like corals, eurypterids, graptolites, nautiloids, and trilobites at varying times. During the Carboniferous period, the sea was replaced by lushly vegetated coastal swamps. West Virginia is an excellent source of fossil plants due to these deposits. These swamps were home to amphibians. A gap in the local rock record spans from the Permian to the end of the Cenozoic. West Virginia was never the site of glacial activity during the Ice Age, but the state was home to creatures like mammoths, mastodons, and giant ground sloths. One local ground sloth, Megalonyx jeffersonii, was subject to the scholarly investigations of Thomas Jefferson, who misinterpreted the large-clawed remains as belonging to a lion-like predator. In 2008, this species was designated the West Virginia state fossil.
The Bluefield Formation is a geologic formation in West Virginia. It preserves fossils dating back to the Mississippian subperiod of the Carboniferous period. Sediments of this age formed along a large marine basin lying in the region of what is now the Appalachian Plateau. The Bluefield Formation is the lowest section of the primarily siliciclastic Mauch Chunk Group, underlying the Stony Gap Sandstone Member of the Hinton Formation and overlying the limestone-rich Greenbrier Group.
Lake Monongahela was a proglacial lake in western Pennsylvania, West Virginia, and Ohio. It formed during the Pre-Illinoian ice epoch when the retreat of the ice sheet northwards blocked the drainage of these valleys to the north. The lake formed south of the ice front continued to rise until it was able to breach a low divide near New Martinsville, West Virginia. The overflow was the beginning of the process which created the modern Ohio River valley.
The geology of Ohio formed beginning more than one billion years ago in the Proterozoic eon of the Precambrian. The igneous and metamorphic crystalline basement rock is poorly understood except through deep boreholes and does not outcrop at the surface. The basement rock is divided between the Grenville Province and Superior Province. When the Grenville Province crust collided with Proto-North America, it launched the Grenville orogeny, a major mountain building event. The Grenville mountains eroded, filling in rift basins and Ohio was flooded and periodically exposed as dry land throughout the Paleozoic. In addition to marine carbonates such as limestone and dolomite, large deposits of shale and sandstone formed as subsequent mountain building events such as the Taconic orogeny and Acadian orogeny led to additional sediment deposition. Ohio transitioned to dryland conditions in the Pennsylvanian, forming large coal swamps and the region has been dryland ever since. Until the Pleistocene glaciations erased these features, the landscape was cut with deep stream valleys, which scoured away hundreds of meters of rock leaving little trace of geologic history in the Mesozoic and Cenozoic.
