Virgilian series

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The Virgilian series is the most recent part of the Pennsylvanian epoch in the North American geologic classification series. [1] During Virgilian times, the top of the Conemaugh and the entire Monongahela group were deposited. [2] As with other Carboniferous series, it comprises cyclothems, or distinct cycles of sedimentary rock formation.

Monongahela cyclothems (youngest at top)

Note: the names below are of the Conemaugh age, not Monongahela age

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The Carboniferous is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period 358.9 million years ago (Mya), to the beginning of the Permian Period, 298.9 Mya. The name Carboniferous means "coal-bearing" and derives from the Latin words carbō ("coal") and ferō, and was coined by geologists William Conybeare and William Phillips in 1822.

The Pennsylvanian is, in the ICS geologic timescale, the younger of two subperiods of the Carboniferous Period. It lasted from roughly 323.2 million years ago to 298.9 million years ago. As with most other geochronologic units, the rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by a few hundred thousand years. The Pennsylvanian is named after the U.S. state of Pennsylvania, where the coal-productive beds of this age are widespread.

Monongahela River River in Pennsylvania and West Virginia, United States

The Monongahela River —often 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's entire length is navigable via a series of locks and dams.

<i>Eryops</i> Species of amphibian

Eryops meaning "drawn-out face" because most of its skull was in front of its eyes is a genus of extinct, amphibious temnospondyls. It contains the single species Eryops megacephalus, the fossils of which are found mainly in early Permian rocks of the Texas Red Beds, located in Archer County, Texas. Fossils have also been found in late Carboniferous period rocks from New Mexico. Several complete skeletons of Eryops have been found in lower Permian rocks, but skull bones and teeth are its most common fossils.

Seatearth is a British coal mining term, which is used in the geological literature. As noted by Jackson, a seatearth is the layer of sedimentary rock underlying a coal seam. Seatearths have also been called seat earth, "seat rock", or "seat stone" in the geologic literature. Depending on its physical characteristics, a number of different names, such as underclay, fireclay, flint clay, and ganister can be applied to a specific seatearth.

<i>Dendrerpeton</i> Extinct genus of amphibians

Dendrerpeton is a genus of an extinct group of temnospondyl amphibians. Its fossils have been found primarily in the Joggins Formation and in Ireland. It lived during the Carboniferous and is said to be around 309–316 million years of age, corresponding to more specifically the Westphalian (stage) age. Of terrestrial temnospondyl amphibians evolution, it represents the first stage. Although multiple species have been proposed, the species unanimously recognized is D. acadianum. This species name comes from “Acadia” which is the name for ancient Indian Nova Scotia. It refers to the location of the coal field at which the fossil was found.

<i>Archaeovenator</i> Extinct genus of tetrapods

Archaeovenator is an extinct genus of Late Carboniferous varanopid synapsids known from Greenwood County, Kansas of the United States. It was first named by Robert R. Reisz and David W. Dilkes in 2003 and the type species is Archaeovenator hamiltonensis. Archaeovenator hamiltonensis is known from the holotype KUVP 12483, a three-dimensionally preserved, nearly complete and articulated skeleton, including the skull, with limbs and girdles slightly separated from postcranial skeleton. It was collected in the Hamilton Quarry, from the Calhouns Shale Formation of the Shawnee Group, dating to the Virgilian stage of the Late Pennsylvanian Series, about 300 million years ago. The generic name is derived from the Latin Archaeo and venator, meaning "ancient hunter". The specific name is named after its finding place Hamilton Quarry. Archaeovenator is the oldest and the basalmost known varanopid, as it is the sister taxon to all other known varanopsids.

Pottsville Formation

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.

<i>Neopteroplax</i> Extinct genus of amphibians

Neopteroplax is an extinct genus of eogyrinid embolomere closely related to European genera such as Eogyrinus and Pteroplax. Members of this genus were among the largest embolomeres in North America. Neopteroplax is primarily known from a large skull found in Ohio, although fragmentary embolomere fossils from Texas and New Mexico have also been tentatively referred to the genus. Despite its similarities to specific European embolomeres, it can be distinguished from them due to a small number of skull and jaw features, most notably a lower surangular at the upper rear portion of the lower jaw.

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.

Pittsburgh coal seam

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 Namurian is a stage in the regional stratigraphy of northwest Europe with an age between roughly 326 and 313 Ma. It is a subdivision of the Carboniferous system or period and the regional Silesian series. The Namurian is named for the Belgian city and province of Namur where strata of this age occur. The Millstone Grit Group in the lithostratigraphy of northern England and parts of Wales is also of Namurian age.

The Westphalian is a stage in the regional stratigraphy of northwest Europe with an age between roughly 313 and 304 Ma. It is a subdivision of the Carboniferous system or period and the regional Silesian series. The Westphalian is named for the region of Westphalia in western Germany where strata of this age occur. The Coal Measures of England and Wales are also largely of Westphalian age though they also extend into the succeeding Stephanian.

<i>Fedexia</i> Extinct genus of amphibians

Fedexia is an extinct genus of carnivorous temnospondyl within the family Trematopidae. It lived 300 million years ago during the late Carboniferous period. It is estimated to have been 2 feet (0.61 m) long, and likely resembled a salamander. Fedexia is known from a single skull found in Moon Township, Pennsylvania. It is named after the shipping service FedEx, which owned the land where the holotype specimen was first found.

Casselman Formation

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.

Carboniferous rainforest collapse Extinction event at the end of the Moscovian in the Carboniferous

The Carboniferous rainforest collapse (CRC) was a minor extinction event that occurred around 305 million years ago in the Carboniferous period. It altered the vast coal forests that covered the equatorial region of Euramerica. This event may have fragmented the forests into isolated refugia or ecological 'islands', which in turn encouraged dwarfism and, shortly after, extinction of many plant and animal species. Following the event, coal-forming tropical forests continued in large areas of the Earth, but their extent and composition were changed.

Coal measures

The coal measures is a lithostratigraphical term for the coal-bearing part of the Upper Carboniferous System. In the United Kingdom, the Coal Measures Group consists of the Upper Coal Measures Formation, the Middle Coal Measures Formation and the Lower Coal Measures Formation. The group records the deposition of fluvio-deltaic sediments which consists mainly of clastic rocks interstratified with the beds of coal. In most places, the coal measures are underlain by coarser clastic sequences known as Millstone Grit, of Namurian age. The top of the coal measures may be marked by an unconformity, the overlying rocks being Permian or later in age. In some parts of Britain, however, the Coal Measures grade up into mainly coal-barren red beds of late Westphalian and possibly Stephanian age. Within the Pennine Basin these barren measures are now referred to as the Warwickshire Group, from the district where they achieve their thickest development.

Glenshaw Formation

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.

Madera Group

The Madera Group is a group of geologic formations in northern New Mexico. Its fossil assemblage dates the formation to the middle to late Pennsylvanian period.

<i>Macroneuropteris</i> Extinct genus of plants

Macroneuropteris is a genus of Carboniferous seed plants in the order Medullosales. The genus is best known for the species Macroneuropteris scheuchzeri, a medium-size tree that was common throughout the late Carboniferous Euramerica. Three similar species, M. macrophylla, M. britannica and M. subauriculata are also included in the genus.

References

  1. Heckel, P. H.; Clayton, G. (2005). "The Carboniferous System. Use of the new official names for the subsystems, series, and stages". Geologica Acta. doi:10.1344/105.000000354.
  2. Eble, Cortland F.; Pierce, Brenda S.; Grady, William C. (2005). "Palynology, petrography and geochemistry of the Sewickley coal bed (Monongahela Group, Late Pennsylvanian), Northern Appalachian Basin, USA". International Journal of Coal Geology. doi:10.1016/S0166-5162(03)00110-1.