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91-601: Brontë Country is a name given to an area of south Pennine hills west of Bradford in West Yorkshire , England . The name comes from the Brontë sisters , who wrote such literary classics as Jane Eyre ( Charlotte Brontë ), Wuthering Heights ( Emily Brontë ), and The Tenant of Wildfell Hall ( Anne Brontë ) while living in the area. The geology of the Brontë country is mainly gritstone . The area includes

182-431: A 100 kyr Milankovitch cycle , and so each cyclothem represents a cycle of sea level fall and rise over a 100 kyr period. Coal forms when organic matter builds up in waterlogged, anoxic swamps, known as peat mires, and is then buried, compressing the peat into coal. The majority of Earth's coal deposits were formed during the late Carboniferous and early Permian. The plants from which they formed contributed to changes in

273-486: A defined GSSP. The fusulinid Aljutovella aljutovica can be used to define the base of the Moscovian across the northern and eastern margins of Pangea, however, it is restricted in geographic area, which means it cannot be used for global correlations. The first appearance of the conodonts Declinognathodus donetzianus or Idiognathoides postsulcatus have been proposed as a boundary marking species and potential sites in

364-580: A formalised Carboniferous unit by William Conybeare and William Phillips in 1822 and then into the Carboniferous System by Phillips in 1835. The Old Red Sandstone was later considered Devonian in age. The similarity in successions between the British Isles and Western Europe led to the development of a common European timescale with the Carboniferous System divided into the lower Dinantian , dominated by carbonate deposition and

455-474: A major evolutionary radiation during the late Carboniferous. Vast swaths of forests and swamps covered the land, which eventually became the coal beds characteristic of the Carboniferous stratigraphy evident today. The later half of the period experienced glaciations , low sea level, and mountain building as the continents collided to form Pangaea . A minor marine and terrestrial extinction event,

546-431: A shallow, tropical seaway which stretched from Southern California to Alaska. The boundary is within a cyclothem sequence of transgressive limestones and fine sandstones , and regressive mudstones and brecciated limestones. The Moscovian Stage is named after shallow marine limestones and colourful clays found around Moscow, Russia. It was first introduced by Sergei Nikitin in 1890. The Moscovian currently lacks

637-645: A similar stratigraphy but divided it into two systems rather than one. These are the lower carbonate-rich sequence of the Mississippian System and the upper siliciclastic and coal-rich sequence of the Pennsylvanian . The United States Geological Survey officially recognised these two systems in 1953. In Russia, in the 1840s British and Russian geologists divided the Carboniferous into the Lower, Middle and Upper series based on Russian sequences. In

728-451: A single sedimentary cycle, with an erosional surface at its base. Whilst individual cyclothems are often only metres to a few tens of metres thick, cyclothem sequences can be many hundreds to thousands of metres thick and contain tens to hundreds of individual cyclothems. Cyclothems were deposited along continental shelves where the very gentle gradient of the shelves meant even small changes in sea level led to large advances or retreats of

819-648: A tropical wetland environment. Extensive coal deposits developed within the cyclothem sequences that dominated the Pennsylvanian sedimentary basins associated with the growing orogenic belt. Subduction of the Panthalassic oceanic plate along its western margin resulted in the Antler orogeny in the Late Devonian to Early Mississippian. Further north along the margin, slab roll-back , beginning in

910-423: A variety of methods for reconstructing past atmospheric oxygen levels, including the charcoal record, halite gas inclusions, burial rates of organic carbon and pyrite , carbon isotopes of organic material, isotope mass balance and forward modelling. Depending on the preservation of source material, some techniques represent moments in time (e.g. halite gas inclusions), whilst others have a wider time range (e.g.

1001-750: A warmer climate. This rapid rise in CO 2 may have been due to a peak in pyroclastic volcanism and/or a reduction in burial of terrestrial organic matter. The LPIA peaked across the Carboniferous-Permian boundary. Widespread glacial deposits are found across South America, western and central Africa, Antarctica, Australia, Tasmania, the Arabian Peninsula, India, and the Cimmerian blocks, indicating trans-continental ice sheets across southern Gondwana that reached to sea-level. In response to

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1092-706: Is a geologic period and system of the Paleozoic era that spans 60 million years from the end of the Devonian Period 358.9 Ma (million years ago) to the beginning of the Permian Period, 298.9 Ma. It is the fifth and penultimate period of the Paleozoic era and the fifth period of the Phanerozoic eon . In North America , the Carboniferous is often treated as two separate geological periods,

1183-720: Is a region of moorland and hill country in northern England lying towards the southern end of the Pennines . In the west it includes the Rossendale Valley and the West Pennine Moors . It is bounded by the Greater Manchester conurbation in the west and the Bowland Fells and Yorkshire Dales to the north. To the east it is fringed by the towns of West Yorkshire whilst to the south it

1274-545: Is bounded by the Peak District . The rural South Pennine Moors constitutes both a Site of Special Scientific Interest and Special Area of Conservation . The Southern Pennines National Character Area defined by Natural England includes the West Pennine Moors and is a landscape of broad moorland, flat-topped hills and fields enclosed by dry stone walls. Settlements built from local gritstone occupy river valleys with wooded sides. Peat soils and blanket bog on

1365-606: Is difficult. The Tournaisian Stage is named after the Belgian city of Tournai . It was introduced in scientific literature by Belgian geologist André Dumont in 1832. The GSSP for the base of the Carboniferous System, Mississippian Subsystem and Tournaisian Stage is located at the La Serre section in Montagne Noire , southern France. It is defined by the first appearance of the conodont Siphonodella sulcata within

1456-528: Is named after the Russian village of Gzhel , near Ramenskoye , not far from Moscow. The name and type locality were defined by Sergei Nikitin in 1890. The Gzhelian currently lacks a defined GSSP. The first appearance of the fusulinid Rauserites rossicus and Rauserites stuckenbergi can be used in the Boreal Sea and Paleo-Tethyan regions but not eastern Pangea or Panthalassa margins. Potential sites in

1547-631: Is that a delay between the development of trees with the wood fibre lignin and the subsequent evolution of lignin-degrading fungi gave a period of time where vast amounts of lignin-based organic material could accumulate. Genetic analysis of basidiomycete fungi, which have enzymes capable of breaking down lignin, supports this theory by suggesting this fungi evolved in the Permian. However, significant Mesozoic and Cenozoic coal deposits formed after lignin-digesting fungi had become well established, and fungal degradation of lignin may have already evolved by

1638-447: Is the period during which both terrestrial animal and land plant life was well established. Stegocephalia (four-limbed vertebrates including true tetrapods ), whose forerunners ( tetrapodomorphs ) had evolved from lobe-finned fish during the preceding Devonian period, became pentadactylous during the Carboniferous. The period is sometimes called the Age of Amphibians because of

1729-663: Is underway in the Urals and Nashui, Guizhou Province, southwestern China for a suitable site for the GSSP with the proposed definition for the base of the Serpukhovian as the first appearance of conodont Lochriea ziegleri . The Pennsylvanian was proposed by J.J.Stevenson in 1888, named after the widespread coal-rich strata found across the state of Pennsylvania. The closure of the Rheic Ocean and formation of Pangea during

1820-524: The Carboniferous rainforest collapse , occurred at the end of the period, caused by climate change. Atmospheric oxygen levels, originally thought to be consistently higher than today throughout the Carboniferous, have been shown to be more variable, increasing from low levels at the beginning of the Period to highs of 25-30%. The development of a Carboniferous chronostratigraphic timescale began in

1911-717: The Gulf of Mexico in the west to Turkey in the east. The orogeny was caused by a series of continental collisions between Laurussia, Gondwana and the Armorican Terrane Assemblage (much of modern-day Central and Western Europe including Iberia ) as the Rheic Ocean closed and Pangea formed. This mountain building process began in the Middle Devonian and continued into the early Permian. The Armorican terranes rifted away from Gondwana during

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2002-677: The Kuznetsk Basin . The northwest to eastern margins of Siberia were passive margins along the Mongol-Okhotsk Ocean on the far side of which lay Amuria. From the mid Carboniferous, subduction zones with associated magmatic arcs developed along both margins of the ocean. The southwestern margin of Siberia was the site of a long lasting and complex accretionary orogen. The Devonian to early Carboniferous Siberian and South Chinese Altai accretionary complexes developed above an east-dipping subduction zone, whilst further south,

2093-586: The Magnitogorsk island arc , which lay between Kazakhstania and Laurussia in the Ural Ocean , collided with the passive margin of northeastern Laurussia ( Baltica craton ). The suture zone between the former island arc complex and the continental margin formed the Main Uralian Fault , a major structure that runs for more than 2,000 km along the orogen. Accretion of the island arc

2184-636: The Rochdale Canal between Greater Manchester and Lancashire in the west and West Yorkshire to the east. The Huddersfield Narrow Canal and the Manchester to Huddersfield railway pass through the Standedge Tunnels and the A62 road crosses the moorland at Standedge . The Leeds and Liverpool Canal passes through Bingley and Keighley en route to Skipton. Natural England describes

2275-511: The diversification of early amphibians such as the temnospondyls , which became dominant land vertebrates, as well as the first appearance of amniotes including synapsids (the clade to which modern mammals belong) and sauropsids (which include modern reptiles and birds) during the late Carboniferous. Land arthropods such as arachnids (e.g. trigonotarbids and Pulmonoscorpius ), myriapods (e.g. Arthropleura ) and especially insects (particularly flying insects ) also underwent

2366-870: The 1890s these became the Dinantian, Moscovian and Uralian stages. The Serpukivian was proposed as part of the Lower Carboniferous, and the Upper Carboniferous was divided into the Moscovian and Gzhelian . The Bashkirian was added in 1934. In 1975, the ICS formally ratified the Carboniferous System, with the Mississippian and Pennsylvanian subsystems from the North American timescale, the Tournaisian and Visean stages from

2457-550: The 18th century, water powered mills were vital for industrial expansion of the textile industry, initially for spinning cotton, but subsequently for woollens and worsteds. Walking, mountain-biking and horseriding are common pastimes enjoyed in the area. Numerous walking trails have been established including, amongst many others, the Calderdale Way and the Bronte Way . The long-established Pennine Way passes through

2548-526: The Bashkirian, the late Moscovian and the latest Kasimovian to mid-Gzhelian are inferred from the disappearance of glacial sediments, the appearance of deglaciation deposits and rises in sea levels. In the early Kasimovian there was short-lived (<1 million years) intense period of glaciation, with atmospheric CO 2 concentration levels dropping as low as 180 ppm. This ended suddenly as a rapid increase in CO 2 concentrations to c. 600 ppm resulted in

2639-567: The Brontë sisters' novels include Oakwell Hall (Fieldhead in Shirley ), Red House (Briarmains in Shirley ), and Gawthorpe Hall and Wycoller Hall (Ferndean Manor in Jane Eyre ). The film Brontë Country: The Story of the Emily, Charlotte & Anne Brontë discusses the area's geography and history, and the history of the Brontë family. South Pennines The South Pennines

2730-764: The Carboniferous Earth's atmosphere, and the coal fueled the Industrial Revolution . During the Pennsylvanian, vast amounts of organic debris accumulated in the peat mires that formed across the low-lying, humid equatorial wetlands of the foreland basins of the Central Pangean Mountains in Laurussia, and around the margins of the North and South China cratons. During glacial periods, low sea levels exposed large areas of

2821-609: The Carboniferous, the Tarim craton lay along the northwestern edge of North China. Subduction along the Kazakhstanian margin of the Turkestan Ocean resulted in collision between northern Tarim and Kazakhstania during the mid Carboniferous as the ocean closed. The South Tian Shan fold and thrust belt , which extends over 2,000 km from Uzbekistan to northwest China, is the remains of this accretionary complex and forms

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2912-762: The Early Mississippian, led to the rifting of the Yukon-Tanana terrane and the opening of the Slide Mountain Ocean . Along the northern margin of Laurussia, orogenic collapse of the Late Devonian to Early Mississippian Innuitian orogeny led to the development of the Sverdrup Basin . Much of Gondwana lay in the southern polar region during the Carboniferous. As the plate moved, the South Pole drifted from southern Africa in

3003-513: The Early to Middle Mississippian, carbonate production occurred to depth across the gently dipping continental slopes of Laurussia and North and South China ( carbonate ramp architecture) and evaporites formed around the coastal regions of Laurussia, Kazakhstania, and northern Gondwana. From the late Visean, the cooling climate restricted carbonate production to depths of less than c. 10 m forming carbonate shelves with flat-tops and steep sides. By

3094-437: The ICS ratify global stages based on a Global Boundary Stratotype Section and Point (GSSP) from a single formation (a stratotype ) identifying the lower boundary of the stage. Only the boundaries of the Carboniferous System and three of the stage bases are defined by global stratotype sections and points because of the complexity of the geology. The ICS subdivisions from youngest to oldest are as follows: The Mississippian

3185-491: The Kasimovian covers a period of globally low sea level, which has resulted in disconformities within many sequences of this age. This has created difficulties in finding suitable marine fauna that can used to correlate boundaries worldwide. The Kasimovian currently lacks a defined GSSP; potential sites in the southern Urals, southwest USA and Nashui, Guizhou Province, southwestern China are being considered. The Gzhelian

3276-483: The Late Ordovician . As they drifted northwards the Rheic Ocean closed in front of them, and they began to collide with southeastern Laurussia in the Middle Devonian. The resulting Variscan orogeny involved a complex series of oblique collisions with associated metamorphism , igneous activity, and large-scale deformation between these terranes and Laurussia, which continued into the Carboniferous. During

3367-665: The Late Pennsylvanian, deformation along the Alleghanian orogen became northwesterly-directed compression . The Uralian orogeny is a north–south trending fold and thrust belt that forms the western edge of the Central Asian Orogenic Belt . The Uralian orogeny began in the Late Devonian and continued, with some hiatuses, into the Jurassic . From the Late Devonian to early Carboniferous,

3458-637: The Paleo-Tethys to the southwest and Panthalassa to the northeast. Cyclothem sediments with coal and evaporites were deposited across the passive margins that surrounded both continents. The Carboniferous climate was dominated by the Late Paleozoic Ice Age (LPIA), the most extensive and longest icehouse period of the Phanerozoic, which lasted from the Late Devonian to the Permian (365 Ma-253 Ma). Temperatures began to drop during

3549-463: The Pennsylvanian, cyclothems were deposited in shallow, epicontinental seas across the tropical regions of Laurussia (present day western and central US, Europe, Russia and central Asia) and the North and South China cratons . The rapid sea levels fluctuations they represent correlate with the glacial cycles of the Late Paleozoic Ice Age. The advance and retreat of ice sheets across Gondwana followed

3640-402: The Pennsylvanian, together with widespread glaciation across Gondwana led to major climate and sea level changes, which restricted marine fauna to particular geographic areas thereby reducing widespread biostratigraphic correlations. Extensive volcanic events associated with the assembling of Pangea means more radiometric dating is possible relative to the Mississippian. The Bashkirian Stage

3731-426: The Period. This was not a steady rise, but included peaks and troughs reflecting the dynamic climate conditions of the time. How the atmospheric oxygen concentrations influenced the large body size of arthropods and other fauna and flora during the Carboniferous is also a subject of ongoing debate. The changing climate was reflected in regional-scale changes in sedimentation patterns. In the relatively warm waters of

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3822-485: The Permian. The Kazakhstanian microcontinent is composed of a series of Devonian and older accretionary complexes. It was strongly deformed during the Carboniferous as its western margin collided with Laurussia during the Uralian orogen and its northeastern margin collided with Siberia. Continuing strike-slip motion between Laurussia and Siberia led the formerly elongate microcontinent to bend into an orocline . During

3913-661: The South Pennine moorlands as the Watershed Landscape where the area's high rainfall fills a multitude of reservoirs. The South Pennines and its fringe has a population of more than a million people. Woodland covers about 4% of the terrain mostly on steep valley sides. The South Pennines provide evidence of Mesolithic , the late Bronze Age and Iron Age findings. The Romans built roads and built forts in Ilkley and at Castleshaw . They also dug coal which

4004-639: The South Pennines includes Rombalds Moor , Rishworth Moor, Haworth Moor, Turton Moor and Castleshaw Moor. The highest point of the M62 motorway , the highest motorway in England, is at 1,221 feet (372 m) on Windy Hill near Junction 22. The rivers Aire , Calder and Colne drain the area to the east and the Roch and Irwell to the west. The Calder Valley provides a low-level route for road, railway and

4095-416: The South Pennines mostly cover the Pennine area between the Yorkshire Dales, Bowlands Fells and Peak District. It is separated from the Yorkshire Dales to the north by the Aire Gap , the Bowland Fells to the north west by the Ribble Valley and the Peak District to the south by the Tame Valley , Standedge and Holme Valley . The West Lancashire Coastal Plain and Greater Manchester conurbation are both to

4186-432: The Urals and Nashui, Guizhou Province, southwestern China are being considered. The Kasimovian is the first stage in the Upper Pennsylvanian. It is named after the Russian city of Kasimov , and was originally included as part of Nikitin's 1890 definition of the Moscovian. It was first recognised as a distinct unit by A.P. Ivanov in 1926, who named it the " Tiguliferina " Horizon after a type of brachiopod . The boundary of

4277-431: The Urals and Nashui, Guizhou Province, southwestern China for the GSSP are being considered. The GSSP for the base of the Permian is located in the Aidaralash River valley near Aqtöbe , Kazakhstan and was ratified in 1996. The beginning of the stage is defined by the first appearance of the conodont Streptognathodus postfusus . A cyclothem is a succession of non-marine and marine sedimentary rocks , deposited during

4368-414: The Visean of c. 15.3%, although with large uncertainties; and, pyrite records suggest levels of c. 15% early in the Carboniferous, to over 25% during the Pennsylvanian, before dropping back below 20% towards the end. However, whilst exact numbers vary, all models show an overall increase in atmospheric oxygen levels from a low of between 15-20% at the beginning of the Carboniferous to highs of 25-30% during

4459-410: The Western European and the Serpukhovian, Bashkirian, Moscovian, Kasimovian and Gzhelian from the Russian. With the formal ratification of the Carboniferous System, the Dinantian, Silesian, Namurian, Westphalian and Stephanian became redundant terms, although the latter three are still in common use in Western Europe. Stages can be defined globally or regionally. For global stratigraphic correlation,

4550-406: The Zharma-Saur arc formed along the northeastern margin of Kazakhstania. By the late Carboniferous, all these complexes had accreted to the Siberian craton as shown by the intrusion of post-orogenic granites across the region. As Kazakhstania had already accreted to Laurussia, Siberia was effectively part of Pangea by 310 Ma, although major strike-slip movements continued between it and Laurussia into

4641-501: The area. The South Pennines Walk & Ride Festival which takes place annually in September is a two-week celebration of the area's landscape . Typical events include guided walks, mountain bike rides, horse rides, orienteering events and evening talks by noted speakers. 53°37′16″N 1°44′28″W  /  53.621°N 1.741°W  / 53.621; -1.741 Carboniferous The Carboniferous ( / ˌ k ɑːr b ə ˈ n ɪ f ər ə s / KAR -bə- NIF -ər-əs )

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4732-477: The average temperature in the tropics c. 24 °C (75 °F) and in polar regions c. -23 °C (-10 °F), whilst during the Early Tournaisian Warm Interval (358-353 Ma) the GAT was c. 22 °C (72 °F), the tropics c. 30 °C (86 °F) and polar regions c. 1.5 °C (35 °F). Overall, for the Ice Age the GAT was c. 17 °C (62 °F), with tropical temperatures c. 26 °C and polar temperatures c. -9.0 °C (16 °F). There are

4823-493: The boundary, is not seen at the La Serre site making precise correlation difficult. The Viséan Stage was introduced by André Dumont in 1832 and is named after the city of Visé , Liège Province , Belgium. In 1967, the base of the Visean was officially defined as the first black limestone in the Leffe facies at the Bastion Section in the Dinant Basin . These changes are now thought to be ecologically driven rather than caused by evolutionary change, and so this has not been used as

4914-410: The charcoal record and pyrite). Results from these different methods for the Carboniferous vary. For example: the increasing occurrence of charcoal produced by wildfires from the Late Devonian into the Carboniferous indicates increasing oxygen levels, with calculations showing oxygen levels above 21% for most of the Carboniferous; halite gas inclusions from sediments dated 337-335 Ma give estimates for

5005-437: The continental shelves. Major river channels, up to several kilometres wide, stretched across these shelves feeding a network of smaller channels, lakes and peat mires. These wetlands were then buried by sediment as sea levels rose during interglacials . Continued crustal subsidence of the foreland basins and continental margins allowed this accumulation and burial of peat deposits to continue over millions of years resulting in

5096-436: The earlier Mississippian and the later Pennsylvanian . The name Carboniferous means " coal -bearing", from the Latin carbō (" coal ") and ferō ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern "system" names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. Carboniferous

5187-475: The early Carboniferous Kanimblan Orogeny . Continental arc magmatism continued into the late Carboniferous and extended round to connect with the developing proto-Andean subduction zone along the western South American margin of Gondwana. Shallow seas covered much of the Siberian craton in the early Carboniferous. These retreated as sea levels fell in the Pennsylvanian and as the continent drifted north into more temperate zones extensive coal deposits formed in

5278-416: The early Carboniferous in North China. However, bauxite deposits immediately above the regional mid Carboniferous unconformity indicate warm tropical conditions and are overlain by cyclothems including extensive coals. South China and Annamia (Southeast Asia) rifted from Gondwana during the Devonian. During the Carboniferous, they were separated from each other and North China by the Paleoasian Ocean with

5369-503: The early Carboniferous to eastern Antarctica by the end of the period. Glacial deposits are widespread across Gondwana and indicate multiple ice centres and long-distance movement of ice. The northern to northeastern margin of Gondwana (northeast Africa, Arabia, India and northeastern West Australia) was a passive margin along the southern edge of the Paleo-Tethys with cyclothem deposition including, during more temperate intervals, coal swamps in Western Australia. The Mexican terranes along

5460-401: The end Carboniferous Coal Measures which in this region are all assigned to the Pennine Lower Coal Measures Formation . It comprises mudstones, siltstones and sandstones and of course coal seams. Coal Measures rocks occur along the eastern and western margins of the region, on either side of the ‘Pennine Anticline’, and across much of the West Pennines. Although precise definitions vary,

5551-406: The end of the Carboniferous, extension and rifting across the northern margin of Gondwana led to the breaking away of the Cimmerian Terrane during the early Permian and the opening of the Neo-Tethys Ocean . Along the southeastern and southern margin of Gondwana (eastern Australia and Antarctica), northward subduction of Panthalassa continued. Changes in the relative motion of the plates resulted in

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5642-403: The end of the Devonian, even if the specific enzymes used by basidiomycetes had not. The second theory is that the geographical setting and climate of the Carboniferous were unique in Earth's history: the co-occurrence of the position of the continents across the humid equatorial zone, high biological productivity, and the low-lying, water-logged and slowly subsiding sedimentary basins that allowed

5733-409: The evolutionary lineage from Siphonodella praesulcata to Siphonodella sulcata . This was ratified by the ICS in 1990. However, in 2006 further study revealed the presence of Siphonodella sulcata below the boundary, and the presence of Siphonodella praesulcata and Siphonodella sulcata together above a local unconformity . This means the evolution of one species to the other, the definition of

5824-425: The formation of thick and widespread coal formations. During the warm interglacials, smaller coal swamps with plants adapted to the temperate conditions formed on the Siberian craton and the western Australian region of Gondwana. There is ongoing debate as to why this peak in the formation of Earth's coal deposits occurred during the Carboniferous. The first theory, known as the delayed fungal evolution hypothesis,

5915-434: The late 18th century. The term "Carboniferous" was first used as an adjective by Irish geologist Richard Kirwan in 1799 and later used in a heading entitled "Coal-measures or Carboniferous Strata" by John Farey Sr. in 1811. Four units were originally ascribed to the Carboniferous, in ascending order, the Old Red Sandstone , Carboniferous Limestone , Millstone Grit and the Coal Measures . These four units were placed into

6006-433: The late Devonian with a short-lived glaciation in the late Famennian through Devonian–Carboniferous boundary, before the Early Tournaisian Warm Interval. Following this, a reduction in atmospheric CO 2 levels, caused by the increased burial of organic matter and widespread ocean anoxia led to climate cooling and glaciation across the south polar region. During the Visean Warm Interval glaciers nearly vanished retreating to

6097-416: The location for the GSSP. Instead, the GSSP for the base of the Visean is located in Bed 83 of the sequence of dark grey limestones and shales at the Pengchong section, Guangxi , southern China. It is defined by the first appearance of the fusulinid Eoparastaffella simplex in the evolutionary lineage Eoparastaffella ovalis – Eoparastaffella simplex and was ratified in 2009. The Serpukhovian Stage

6188-432: The majority of a cyclothem sequence occurred during falling sea levels, when rates of erosion were high, meaning they were often periods of non-deposition. Erosion during sea level falls could also result in the full or partial removal of previous cyclothem sequences. Individual cyclothems are generally less than 10 m thick because the speed at which sea level rose gave only limited time for sediments to accumulate. During

6279-430: The mid Carboniferous, the South American sector of Gondwana collided obliquely with Laurussia's southern margin resulting in the Ouachita orogeny. The major strike-slip faulting that occurred between Laurussia and Gondwana extended eastwards into the Appalachian Mountains where early deformation in the Alleghanian orogeny was predominantly strike-slip. As the West African sector of Gondwana collided with Laurussia during

6370-422: The moors store carbon while high rainfall fills many reservoirs supplying water to the adjacent conurbations. The area is important for recreation having open access areas, footpaths and historic packhorse routes. The area is almost wholly formed from multiple layers of sedimentary rock dating from the Carboniferous period. The oldest of these are the limestones and associated mudstones which outcrop in

6461-417: The northernmost part of the region, though which are thought to underlie the entire area at depth. These are assigned to the Craven Group . Overlying these and occurring widely across the region are the mudstones and sandstones of the Millstone Grit Group . Many of the sandstones, particularly the coarser-grained ones are commonly referred to as gritstones or ‘grits’. The Millstone Grit is in turn overlain by

6552-571: The northwestern Gondwana margin, were affected by the subduction of the Rheic Ocean. However, they lay to west of the Ouachita orogeny and were not impacted by continental collision but became part of the active margin of the Pacific. The Moroccan margin was affected by periods of widespread dextral strike-slip deformation, magmatism and metamorphism associated with the Variscan orogeny. Towards

6643-534: The outskirts of Bradford , is the birthplace of the Brontë sisters and their brother Branwell (their father was rector of Thornton church). The house where they were born still exists as the Brontë Birthplace and in November 2023 was acquired for restoration and preservation as a cultural and educational space. It is located on Market Street in the centre of the village. Other places of interest from

6734-426: The peat mires. As fully marine conditions were established, limestones succeeded these marginal marine deposits. The limestones were in turn overlain by deep water black shales as maximum sea levels were reached. Ideally, this sequence would be reversed as sea levels began to fall again; however, sea level falls tend to be protracted, whilst sea level rises are rapid, ice sheets grow slowly but melt quickly. Therefore,

6825-892: The proto-Andes in Bolivia and western Argentina and the Pan-African mountain ranges in southeastern Brazil and southwest Africa. The main phase of the LPIA (c. 335-290 Ma) began in the late Visean, as the climate cooled and atmospheric CO 2 levels dropped. Its onset was accompanied by a global fall in sea level and widespread multimillion-year unconformities. This main phase consisted of a series of discrete several million-year-long glacial periods during which ice expanded out from up to 30 ice centres that stretched across mid- to high latitudes of Gondwana in eastern Australia, northwestern Argentina, southern Brazil, and central and Southern Africa. Isotope records indicate this drop in CO 2 levels

6916-640: The sea. Cyclothem lithologies vary from mudrock and carbonate-dominated to coarse siliciclastic sediment-dominated sequences depending on the paleo-topography, climate and supply of sediments to the shelf. The main period of cyclothem deposition occurred during the Late Paleozoic Ice Age from the Late Mississippian to early Permian, when the waxing and waning of ice sheets led to rapid changes in eustatic sea level . The growth of ice sheets led global sea levels to fall as water

7007-571: The suture between Kazakhstania and Tarim. A continental magmatic arc above a south-dipping subduction zone lay along the northern North China margin, consuming the Paleoasian Ocean. Northward subduction of the Paleo-Tethys beneath the southern margins of North China and Tarim continued during the Carboniferous, with the South Qinling block accreted to North China during the mid to late Carboniferous. No sediments are preserved from

7098-410: The thick accumulation of peat were sufficient to account for the peak in coal formation. During the Carboniferous, there was an increased rate in tectonic plate movements as the supercontinent Pangea assembled. The continents themselves formed a near circle around the opening Paleo-Tethys Ocean, with the massive Panthalassic Ocean beyond. Gondwana covered the south polar region. To its northwest

7189-568: The uplift and erosion of the more mafic basement rocks of the Central Pangea Mountains at this time, CO 2 levels dropped as low as 175 ppm and remained under 400 ppm for 10 Ma. Temperatures across the Carboniferous reflect the phases of the LPIA. At the extremes, during the Permo-Carboniferous Glacial Maximum (299-293 Ma) the global average temperature (GAT) was c. 13 °C (55 °F),

7280-664: The upper Silesian with mainly siliciclastic deposition. The Dinantian was divided into the Tournaisian and Viséan stages. The Silesian was divided into the Namurian , Westphalian and Stephanian stages. The Tournaisian is the same length as the International Commission on Stratigraphy (ICS) stage, but the Viséan is longer, extending into the lower Serpukhovian . North American geologists recognised

7371-698: The village of Haworth , where the Brontë sisters lived, and where the Brontë Parsonage Museum is located today. Top Withens is said to have been the inspiration for Wuthering Heights . Ponden Hall , which located about half a mile outside Stanbury , is believed to inspire at least two buildings in Brontës' novels: Thrushcross Grange in Wuthering Heights and the eponymous mansion in The Tenant of Wildfell Hall . Thornton , on

7462-751: The west while the West Yorkshire conurbation is to the east. Settlements within the South Pennines include Addingham , Ilkley and Otley in the north, as well as Bingley , Keighley , Haworth and Oxenhope . Halifax , Sowerby Bridge , Hebden Bridge and Todmorden are in the Calder Valley . These also include Marsden , Slaithwaite and Meltham in the south-east, Darwen , Haslingden and Rawtenstall in Lancashire , and Greenfield , Horwich , Ramsbottom , Oldham , Rochdale and Littleborough in Greater Manchester . Moorland in

7553-492: Was Laurussia. These two continents slowly collided to form the core of Pangea. To the north of Laurussia lay Siberia and Amuria . To the east of Siberia, Kazakhstania , North China and South China formed the northern margin of the Paleo-Tethys, with Annamia laying to the south. The Central Pangean Mountains were formed during the Variscan - Alleghanian - Ouachita orogeny. Today their remains stretch over 10,000 km from

7644-506: Was complete by the Tournaisian, but subduction of the Ural Ocean between Kazakhstania and Laurussia continued until the Bashkirian when the ocean finally closed and continental collision began. Significant strike-slip movement along this zone indicates the collision was oblique. Deformation continued into the Permian and during the late Carboniferous and Permian the region was extensively intruded by granites . The Laurussian continent

7735-572: Was formed by the collision between Laurentia , Baltica and Avalonia during the Devonian. At the beginning of the Carboniferous, some models show it at the equator, whilst others place it further south. In either case, the continent drifted northwards, reaching low latitudes in the northern hemisphere by the end of the Period. The Central Pangean Mountain drew in moist air from the Paleo-Tethys Ocean resulting in heavy precipitation and

7826-406: Was further exploited especially during the Industrial Revolution in the late 18th and early 19th centuries. Steep-sided valleys with fast flowing streams provided power and water for the area's early mills and factories. Water-powered corn mills and fulling mills were used in medieval times and more fulling mills were built after the mid-16th century as the woollen industry grew. At the end of

7917-646: Was lock away in glaciers. Falling sea levels exposed large tracts of the continental shelves across which river systems eroded channels and valleys and vegetation broke down the surface to form soils . The non-marine sediments deposited on this erosional surface form the base of the cyclothem. As sea levels began to rise, the rivers flowed through increasingly water-logged landscapes of swamps and lakes. Peat mires developed in these wet and oxygen-poor conditions, leading to coal formation. With continuing sea level rise, coastlines migrated landward and deltas , lagoons and esturaries developed; their sediments deposited over

8008-570: Was proposed by Alexander Winchell in 1870 named after the extensive exposure of lower Carboniferous limestone in the upper Mississippi River valley. During the Mississippian, there was a marine connection between the Paleo-Tethys and Panthalassa through the Rheic Ocean resulting in the near worldwide distribution of marine faunas and so allowing widespread correlations using marine biostratigraphy . However, there are few Mississippian volcanic rocks , and so obtaining radiometric dates

8099-578: Was proposed by Russian stratigrapher Sofia Semikhatova in 1934. It was named after Bashkiria , the then Russian name of the republic of Bashkortostan in the southern Ural Mountains of Russia. The GSSP for the base of the Pennsylvanian Subsystem and Bashkirian Stage is located at Arrow Canyon in Nevada , US and was ratified in 1996. It is defined by the first appearance of the conodont Declinognathodus noduliferus . Arrow Canyon lay in

8190-505: Was proposed in 1890 by Russian stratigrapher Sergei Nikitin . It is named after the city of Serpukhov , near Moscow. currently lacks a defined GSSP. The Visean-Serpukhovian boundary coincides with a major period of glaciation. The resulting sea level fall and climatic changes led to the loss of connections between marine basins and endemism of marine fauna across the Russian margin. This means changes in biota are environmental rather than evolutionary making wider correlation difficult. Work

8281-459: Was triggered by tectonic factors with increased weathering of the growing Central Pangean Mountains and the influence of the mountains on precipitation and surface water flow. Closure of the oceanic gateway between the Rheic and Tethys oceans in the early Bashkirian also contributed to climate cooling by changing ocean circulation and heat flow patterns. Warmer periods with reduced ice volume within

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