The Pennsylvanian Pottsville Formation is a mapped bedrock unit in Pennsylvania, western Maryland, West Virginia, Ohio. The formation is recognized in 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 Pottsville Formation consists of a gray conglomerate, fine to coarse grained sandstone, is known to contain limestone and shale, as well as anthracite and bituminous coal. It is considered a classic orogenic molasse; the formation was first described from a railroad cut south of Pennsylvania. The relationship to the term "Pottsville" and actual lithologic units is complex. Most fundamentally, the unit may be considered a Group; as a Formation, the Pottsville may encompass the following members depending on the state in which it occurs: Alton Coal Member, Anthony Shale Member, Bear Run Member, Bedford Clay Bed, Boggs Member, Boyles Sandstone Member, Bremen Sandstone Member, Brookville Clay Member, Camp Branch Sandstone Member, Campbell Ledge Shale Member, Chestnut Sandstone Member, Connoquenessing Sandstone Member, Dundee Sandstone Member, Flint Ridge Clay Bed or Flint Ridge Shale Member, Harrison Member, Homewood Sandstone Member, Huckleberry Clay Bed, Kanawha Member, Lick Creek Sandstone Member, Lowellville Limestone Member, Lower Mercer Limestone Member, Massilon Sandstone Member, McArthur Member, Mercer Member, Middle Mercer Shale Member, Mount Savage Clay Bed, Olean Conglomerate Member of Olean Sandstone Member, Pine Sandstone Member, Poverty Run Member, Razburg Sandstone Member, Rocky Ridge Sandstone Member, Schuylkill Member, Sciotoville Clay Member, Shades Sandstone Member, Sharon Coal Bed, Sharon Member, Sharp Mountain Member, Straight Ridge Sandstone Member, Straven Conglomerate Member, Tionesta Clay Bed, Tumbling Run Member, Upper Mercer Limestone Member or Upper Mercer Bed, Vandusen Shale Member, Wolf Ridge Sandstone Member.
As a Group, the Pottsville may encompass the following Formations depending on the state in which it occurs: Connoquenessing Formation, Curwensville Formation, Elliott Park Formation, Gurnee Formation, Hance Formation, Homewood Formation or Homewood Sandstone, Mercer Formation, New River Formation, Olean Conglomerate or Olean Formation, Pocahontas Formation, Schuylkill Formation, Sharon Formation or Sharon Sandstone, Sharp Mountain Formation, Tumbling Run Formation. The Pottsville was mapped in the Illinois basin as well at the Formation level, but was renamed the Tradewater Formation in 1997. A 1.3-m interval at the base of the Pottsville in the Broad Top basin in Pennsylvania contains both marine invertebrates and plant fossils of middle Morrowan age. Relative age dating of the Pottsville places it in the early to middle Pennsylvanian period. Pennsylvania: Bilger's Rocks Worlds End State ParkMaryland: Dans Rock, on Dans MountainWest Virginia: Bear Rocks Preserve, Dolly Sods Blackwater Falls and the Blackwater Canyon Canaan Valley Cheat River Gorge Spruce Knob Carboniferous Ohio Carboniferous Pennsylvania Carboniferous West Virginia Pennsylvanian North America
The Columbus Limestone is a mapped bedrock unit consisting of fossiliferous limestone, it occurs in Ohio and Virginia in the United States, in Ontario, Canada. The depositional environment was most shallow marine; the Columbus conformably overlies the Lucas Dolomite in northeastern Ohio, unconformably overlies other dolomite elsewhere. It unconformably underlies the Ohio Shale in northwestern Ohio and the Delaware Limestone in eastern Ohio, its members include: Bellepoint, Tioga Ash Bed, Delhi and East Liberty. The type section is located in Ohio; the glacial grooves on Kelleys Island are cut into the Columbus Limestone. It is quarried there. An exposure in Ontario is located at Ontario; the Columbus Limestone contains brachiopods, bryozoans, corals and echinoderms. Due to their mid-continent depositional environment, the fossils are free of deformation caused by tectonic activity common in the Appalachian Mountains. Tabulate corals include Syringopora tabulata, Favosites hemispherica minuta, Emmonsia polymorpha, Thamnoptychia alternans, Pleurodictyum sp. and Coenites dublinensis.
Rugose corals include Prismatophyllum rugosum, Hexagonaria anna, Eridophyllum seriale, Synaptophyllum simcoense, Amplexus yandelli, Zaphrenthis perovalis, Heterophrentis nitida, Cystiphylloides americanum, Odontophyllum convergens, Siphonophrentis gigantea. Brachiopods include Brevispirifer gregarius; the gastropod Laevidentalhum martinei is present, as well as the crinoid Nucleocrinus verneulli. Fish fossils have been found in the East Liberty Member. Goniatites have been found including Werneroceras staufferi and Tornoceras eberlei. Another cephalopod species is Goldringia cyclops. Relative age dating of the Columbus Limestone places it in the Early to Middle Devonian period; the Columbus has been mined for aggregate. Its Calcium carbonate content is higher. List of types of limestone
The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago to the start of the Silurian Period 443.8 Mya. The Ordovician, named after the Celtic tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in northern Wales into the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, placed them in a system of their own; the Ordovician received international approval in 1960, when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian period, although the end of the period was marked by the Ordovician–Silurian extinction events.
Invertebrates, namely molluscs and arthropods, dominated the oceans. The Great Ordovician Biodiversification Event increased the diversity of life. Fish, the world's first true vertebrates, continued to evolve, those with jaws may have first appeared late in the period. Life had yet to diversify on land. About 100 times as many meteorites struck the Earth per year during the Ordovician compared with today; the Ordovician Period began with a major extinction called the Cambrian–Ordovician extinction event, about 485.4 Mya. It lasted for about 42 million years and ended with the Ordovician–Silurian extinction events, about 443.8 Mya which wiped out 60% of marine genera. The dates given are recent radiometric dates and vary from those found in other sources; this second period of the Paleozoic era created abundant fossils that became major petroleum and gas reservoirs. The boundary chosen for the beginning of both the Ordovician Period and the Tremadocian stage is significant, it correlates well with the occurrence of widespread graptolite and trilobite species.
The base of the Tremadocian allows scientists to relate these species not only to each other, but to species that occur with them in other areas. This makes it easier to place many more species in time relative to the beginning of the Ordovician Period. A number of regional terms have been used to subdivide the Ordovician Period. In 2008, the ICS erected a formal international system of subdivisions. There exist Baltoscandic, Siberian, North American, Chinese Mediterranean and North-Gondwanan regional stratigraphic schemes; the Ordovician Period in Britain was traditionally broken into Early and Late epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, or Upper part of the column; the faunal stages from youngest to oldest are: Late Ordovician Hirnantian/Gamach Rawtheyan/Richmond Cautleyan/Richmond Pusgillian/Maysville/Richmond Middle Ordovician Trenton Onnian/Maysville/Eden Actonian/Eden Marshbrookian/Sherman Longvillian/Sherman Soudleyan/Kirkfield Harnagian/Rockland Costonian/Black River Chazy Llandeilo Whiterock Llanvirn Early Ordovician Cassinian Arenig/Jefferson/Castleman Tremadoc/Deming/Gaconadian The Tremadoc corresponds to the Tremadocian.
The Floian corresponds to the lower Arenig. The Llanvirn occupies the rest of the Darriwilian, terminates with it at the base of the Late Ordovician; the Sandbian represents the first half of the Caradoc. During the Ordovician, the southern continents were collected into Gondwana. Gondwana started the period in equatorial latitudes and, as the period progressed, drifted toward the South Pole. Early in the Ordovician, the continents of Laurentia and Baltica were still independent continents, but Baltica began to move towards Laurentia in the period, causing the Iapetus Ocean between them to shrink; the small continent Avalonia separated from Gondwana and began to move north towards Baltica and Laurentia, opening the Rheic Ocean between Gondwana and Avalonia. The Taconic orogeny, a major mountain-building episode, was well under way in Cambrian times. In the early and middle Ordovician, temperatures were mild, but at the beginning of the Late Ordovician, from 460 to 450 Ma, volcanoes along the margin of the Iapetus Ocean spewed massive amounts of carbon dioxide, a greenhouse gas, into the atmosphere, turning the planet into a hothouse.
Sea levels were high, but as Gondwana moved south, ice accumulated into glaciers and sea levels dropped. At first, low-lying sea beds increased diversity, but glaciation led to mass extinctions as the seas drained and continental shelves became dry land. During the Ordovician, in fact during the Tremadocian, marine transgressions worldwide were the greatest for which evidence is preserved; these volcanic island arcs collided with proto North America to form the Appalachian mountains. By the end of the Late Ordovician the volcanic emissions had stopped. Gondwana had by that time neared the South Pole and was glaciated
The Logan Formation is the name given to a Lower Carboniferous siltstone and conglomeratic unit exposed in east-central Ohio and parts of western West Virginia, USA. The Logan Formation was named by Andrews and described as a "buff-colored, fine-grained sandstone" above the Waverly Formation and below the Maxville Limestone. Bork and Malcuit concluded that the Logan Formation was deposited on a shallow marine shelf in a transgressing sea; the age of the Logan Formation has been established as early Osagean by the occurrences of brachiopods, ammonoids and miospores. Andrews, E. B.. "Report of progress in the second district, Part II, IN Report of progress in 1869". Ohio Division of Geological Survey Report of Progress, 2nd series: 1091–1094. Bork, K. B.. J.. "Paleoenvironments of the Cuyahoga and Logan Formations of central Ohio". Geological Society of America Bulletin. 90: 89–113. Doi:10.1130/0016-760690<1091:potcal>2.0.co. Clayton, G.. L.. "Mississippian miospores from the Cuyahoga and Logan Formations of northeastern Ohio, USA".
Journal of Micropalaeontology. 17: 183–191. Doi:10.1144/jm.17.2.183. Matchen, D. L.. W.. "Incised valley fill interpretation for Mississippian Black Hand Sandstone, Appalachian Basin, USA: Implications for glacial eustacy at Kinderhookian-Osagean boundary". Sedimentary Geology. 191: 89–113. Bibcode:2006SedG..191...89M. Doi:10.1016/j.sedgeo.2006.02.002
Berea Sandstone known as Berea Grit, is a sandstone formation in the U. S. states of Michigan, Pennsylvania, West Virginia, Kentucky. It is named after Ohio; the sandstone is a source of oil and gas. In the Appalachian Basin, Berea Sandstone is present in eastern Ohio, western Pennsylvania, western West Virginia, eastern Kentucky. In the Michigan Basin, the sandstone is present in the eastern part of the state, thickest near Michigan's Thumb; the two deposits are disconnected from each other. The sandstone underlies the Sunbury Shale. Berea Sandstone is light gray to buff-colored in the form of siltstone and fine- to medium-grained sandstone. In places it is hard to distinguish from the underlying Bedford Shale. Berea Sandstone is classified as a member of the Waverly Group. Berea Sandstone is up to 72 meters thick in Lorain County, up to 79 meters thick in Huron County, Michigan; the sandstone was named "Berea Grit" by Ohio geologist J. S. Newberry in 1874, he named it after Berea, for its extensive quarries of the stone.
In Michigan, the petroleum industry has referred to the Ellsworth Shale as "Berea", but this formation is distinct from Berea Sandstone and is laterally separated by Antrim Shale. Berea Sandstone was formed in the Late Devonian period. Prior to the 1970s, it was assigned a Mississippian age; the Devonian-Carboniferous boundary was realigned based on research from Europe, but various geologists were not aware of the changes and so incorrectly assigned Berea Sandstone to the Kinderhookian. The majority of the sand which formed the Berea Sandstone came from the north, flowing in a river from the highlands of eastern Canada, it was deposited in a river delta environment. Pepper, et al. hypothesized that the river flowed first into the Ohio basin before switching course to the Michigan basin, thus the Michigan Berea Sandstone would be younger. There is a downwarp in the Cincinnati arch, called the Ontario sag, that if it was present at the formation of Berea Sandstone, could mean that it formed a continuous belt of sediment between the Appalachian and Michigan basins.
Subsequent erosion disconnected the two deposits. Berea Sandstone is unfossiliferous; however some fossils have been found, including fish of the genera Ctenacanthus and Gonatodus, plants of the genus Annularia, some brachiopods. Buildings constructed of Berea Sandstone include the Johnson County Courthouse in Iowa and the Brown County Courthouse in South Dakota; the Centre Block building of the Parliament of Canada, both before and after reconstruction, uses Berea Sandstone as window and door trim. The simple and significant St. Matthews Roman Catholic Cathedral, in Buffalo, New York, USA, is constructed of Ohio Sandstone, was completed in Year 1928; the church is of Romanesque Architecture, in the visual aesthetic of the Baroque Era, is modeled in the spirit of the famous Cathedral Of Aachen in Western Europe. The Cathedral in Germany, is. St. Matthews is 80 feet wide, 170 feet long, is built in the form of a Cross; the ceiling is 75 feet high, with the superstructure supported by its side walls instead of pillars.
The nave seats 900. Another noteworthy design feature of St. Matthews are the church's amplified chimes, which were installed at time of the Building's construction. In Year 2019, a major rehabilitation and revitalization Effort targeting St. Matthews Church was proposed, to rescue the Building from demolition by its municipality. Historic Place and Historic Sacred Place designations are to be pursued. St. Matthews Roman Catholic Cathedral in Buffalo, New York, USA cost $225,000.00 to build. Berea Sandstone has been used as flagstone and for paving. Fine grained stone has been used for whetstones. Quarrying of Berea Sandstone began in 1830; until around 1840 or 1845, only grindstones were produced before diversifying into building and flagstones. More than a dozen different companies quarried the sandstone, before all consolidating into the Cleveland Stone Company by 1893, the largest sandstone producer in the United States at the time. Berea Sandstone is a source of oil and natural gas. Commercial gas development began in 1859 -- 60 with a well at Ohio.
Oil was discovered in the Berea Sandstone in 1860 in Trumbull County, Ohio. In Michigan, Berea Sandstone oil was first discovered in 1925 at Saginaw. By 2011, oil production from Berea Sandstone led northeastern Kentucky to be the most productive region of that state. List of sandstones Pepper, James F.. "Geology of the Bedford Shale and Berea Sandstone in the Appalachian Basin". United States Geological Survey. Retrieved February 1, 2018. De Witt, Wallace, Jr.. "Age of the Bedford Shale, Berea Sandstone, Simbury Shale in the Appalachian and Michigan Basins, Pennsylvania and Michigan". United States Geological Survey. Retrieved February 22, 2018. Collins, Horace R.. "The Mississippian and Pennsylvanian Systems in the United States – Ohio". United States Geological Survey. Retrieved February 22, 2018. Ells, Garland D.. "The Mississippian and Pennsylvanian Systems in the United States – Michigan". United States Geological Survey. Retrieved February 22, 2018. Catacosinos, Paul A.. Early sedimentary evolution of the Michigan Basin.
Geochronology is the science of determining the age of rocks and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes, whereas relative geochronology is provided by tools such as palaeomagnetism and stable isotope ratios. By combining multiple geochronological indicators the precision of the recovered age can be improved. Geochronology is different in application from biostratigraphy, the science of assigning sedimentary rocks to a known geological period via describing and comparing fossil floral and faunal assemblages. Biostratigraphy does not directly provide an absolute age determination of a rock, but places it within an interval of time at which that fossil assemblage is known to have coexisted. Both disciplines work together hand in hand, however, to the point where they share the same system of naming rock layers and the time spans utilized to classify layers within a stratum; the science of geochronology is the prime tool used in the discipline of chronostratigraphy, which attempts to derive absolute age dates for all fossil assemblages and determine the geologic history of the Earth and extraterrestrial bodies.
By measuring the amount of radioactive decay of a radioactive isotope with a known half-life, geologists can establish the absolute age of the parent material. A number of radioactive isotopes are used for this purpose, depending on the rate of decay, are used for dating different geological periods. More decaying isotopes are useful for longer periods of time, but less accurate in absolute years. With the exception of the radiocarbon method, most of these techniques are based on measuring an increase in the abundance of a radiogenic isotope, the decay-product of the radioactive parent isotope. Two or more radiometric methods can be used in concert to achieve more robust results. Most radiometric methods are suitable for geological time only, but some such as the radiocarbon method and the 40Ar/39Ar dating method can be extended into the time of early human life and into recorded history; some of the used techniques are: Radiocarbon dating. This technique measures the decay of carbon-14 in organic material and can be best applied to samples younger than about 60,000 years.
Uranium–lead dating. This technique measures the ratio of two lead isotopes to the amount of uranium in a mineral or rock. Applied to the trace mineral zircon in igneous rocks, this method is one of the two most used for geologic dating. Monazite geochronology is another example of U–Pb dating, employed for dating metamorphism in particular. Uranium–lead dating is applied to samples older than about 1 million years. Uranium–thorium dating; this technique is used to date speleothems, corals and fossil bones. Its range is from a few years to about 700,000 years. Potassium–argon dating and argon–argon dating; these techniques date metamorphic and volcanic rocks. They are used to date volcanic ash layers within or overlying paleoanthropologic sites; the younger limit of the argon–argon method is a few thousand years. Electron spin resonance dating A series of related techniques for determining the age at which a geomorphic surface was created, or at which surficial materials were buried. Exposure dating uses the concentration of exotic nuclides produced by cosmic rays interacting with Earth materials as a proxy for the age at which a surface, such as an alluvial fan, was created.
Burial dating uses the differential radioactive decay of 2 cosmogenic elements as a proxy for the age at which a sediment was screened by burial from further cosmic rays exposure. Luminescence dating techniques observe'light' emitted from materials such as quartz, diamond and calcite. Many types of luminescence techniques are utilized in geology, including optically stimulated luminescence, cathodoluminescence, thermoluminescence. Thermoluminescence and optically stimulated luminescence are used in archaeology to date'fired' objects such as pottery or cooking stones and can be used to observe sand migration. Incremental dating techniques allow the construction of year-by-year annual chronologies, which can be fixed or floating. Dendrochronology Ice cores Lichenometry Varves A sequence of paleomagnetic poles, which are well defined in age, constitutes an apparent polar wander path; such a path is constructed for a large continental block. APWPs for different continents can be used as a reference for newly obtained poles for the rocks with unknown age.
For paleomagnetic dating, it is suggested to use the APWP in order to date a pole obtained from rocks or sediments of unknown age by linking the paleopole to the nearest point on the APWP. Two methods of paleomagnetic dating have been suggested Rotation method. First method is used for paleomagnetic dating of rocks inside of the same continental block; the second method is used for the folded areas. Magnetostratigraphy determines age from the pattern of magnetic polarity zones in a series of bedded sedimentary and/or volcanic rocks by comparison to the magnetic polarity timescale; the polarity timescale has been determined by dating of seafloor magnetic anomalies, radiometrically dating volcanic rocks within magnetostratigraphic sections, astronomically dating magnetostratigraphic sections. Global trends in isotope compositions Carbon 13 and strontium isotopes, can be used to corr
The Antrim Shale is a formation of Upper Devonian age in the Michigan Basin, in the US state of Michigan, extending into Ohio and Indiana. It is a major source of natural gas in the northern part of the basin; the Antrim Shale was defined by A. C. Lane in 1901, named for type-section exposures in Antrim County, Michigan; the formation was known as the St. Cleric Shale in Michigan, the Genessee Shale in Indiana; the Antrim is a brown to black, pyritic laminated and organic-rich shale, from 60 to 220 feet thick. Total organic content varies from 1% to 20%. In some places the unit includes a gray calcareous shale or limestone, in places a fine-grained sandstone at the base; the formation is called the Kettle Point Formation in Ontario, is the stratigraphic equivalent of the New Albany Shale in the Illinois Basin. It is overlain by the Bedford Shale, underlain in some areas by the Jordan River Formation, elsewhere by the Thunder Bay Limestone; the Antrim Shale, is a major source of shale gas, produces natural gas along a swath across the northern part of the state.
Most natural gas production is in Antrim, Montmorency and Otsego counties. Although the Antrim Shale has produced gas since the 1940s, the play was not active until the late 1980s. During the 1990s, the Antrim became the most drilled shale gas play in the US, with thousands of wells drilled. To date, the shale has produced more than 2.5 TCF from more than 9 thousand wells. Antrim Shale wells produced 140×10^9 cu ft in 2006; the shale appears to be most economic at depths of 600-2,200 feet. Original gas content ranges from 40 to 100 standard cubic feet per ton. Wells are developed on units of from 40-acre to 160-acre. Horizontal drilling is not used. Antrim Shale wells have to pump much initial water before gas production becomes significant, a behavior seen in many coalbed methane wells. Unlike most other shale gas plays, the natural gas from the Antrim appears to be biogenic gas generated by the action of bacteria on the organic-rich rock. Unlike most other shale plays, the Antrim Shale is thermally immature in the gas-productive trend.
In 2007, the Antrim gas field produced 136 billion cubic feet of gas, making it the 13th-largest source of natural gas in the United States. Robert T. Ryder, Fracture Patterns and Their Origin in the Upper Devonian Antrim Shale Gas Reservoir of the Michigan Basin: A Review, US Geological Survey, Open-File Report 96-23, 1996, accessed 3 November 2009. Shale gas in the United States