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40-713: A number of mountain building periods were involved in the formation of the Central Pangean Mountains, including the Acadian , Caledonian , Alleghenian , Mauritanide and Variscan orogenies . The eastern portions of the range are also called the Variscan Mountains . The Central Pangean Mountains were formed during the collision of Euramerica and northern Gondwana as part of the Variscan and Alleghanian orogenies , which began during

80-575: A monsoon climate. This is necessary for the preservation of peat in coal swamps. During the early-mid Permian, the Central Pangean Mountains lay directly beneath the equatorial rainy belt . Data from the loess deposits of the Salagou Formation in France, dating to the Permian, indicates that the upland areas of the Central Pangean Mountains were likely glaciated , despite being located at

120-549: A coastal alluvial plain that was hundreds of miles long. The Middle Devonian to Lower Mississippian siliciclastic strata , deposited by the Catskill Delta, includes black shale , gray shale, sandstone , red beds , and minor argillaceous limestone. The strata was deposited in a four-stage pattern that is observed in each tectophase. The formation of the foreland basin through rapid subsidence initiated transgressive sequences that deposited basinal black shales. After

160-513: A large area of eastern Laurentia. During the course of the orogeny , new faults formed, while older faults were reactivated. Acadian deformation and metamorphism were asymmetric across the strike of the orogen. The Acadian plutons intruded every belt, unlike the deformation/metamorphism, of Avalonia which did not undergo much of the alteration shown in other localities. During the Middle Devonian, centers for volcanoes and uplift formed in

200-567: Is 140,599 as of the 2011 census . It is also noted as the only region outside the Channel Islands to contain native speakers of Jersey Norman . Sea cliffs dominate the peninsula's northern shore along the St. Lawrence River. Cap Gaspé , jutting into the Gulf of St. Lawrence, is the easternmost point of the peninsula. Percé Rock (or Rocher Percé ), an island pierced by a natural arch ,

240-829: Is a peninsula along the south shore of the St. Lawrence River that extends from the Matapedia Valley in Quebec , Canada, into the Gulf of St. Lawrence . It is separated from New Brunswick on its southern side by Chaleur Bay and the Restigouche River . The name Gaspé comes from the Mi'kmaq word gespe'g , meaning "end", referring to the end of the land. The Gaspé Peninsula is slightly larger than Belgium, at 31,075 square kilometres (11,998 sq mi). The population

280-532: Is a nearly flat plateau about 13 km (8 mi) across composed of serpentine bedrock and supporting quite unusual flora. The ascent of Mount Albert from near sea level is challenging, but popular with hikers, offering a view of the St. Lawrence and the Côte-Nord , the river's north shore, part of the ancient bedrock of the Canadian Shield . The interior portions of the peninsula are dominated by

320-537: Is assumed they originated from areas near promontories , areas along the continental margin where deformation is concentrated. The earliest tectophase was located at the St. Lawrence promontory in northern New England and in the Canadian Maritime Provinces. The St. Lawrence tectophase was active during the Early to Middle Devonian with intense transpressional deformation which formed a basin in

360-719: Is believed to come from the margin of Gondwana, sometime in the Early Ordovician. Avalonia rifted from Gondwana during the onset of igneous activity in the Ardennes, Wales, and southeast Ireland that consumed the Tornquist Sea oceanic crust. It drifted in a northerly direction and probably collided with Baltica in the Late Ordovician, and then with Laurentia in the Late Devonian. Evidence for this

400-534: Is consistent with paleomagnetic data which place Avalonia at a temperate latitude during the Ordovician and in a subtropical latitude during the Late Ordovician through the Devonian. The Acadian orogeny resulted from oblique convergence or major transcurrent movement along a large strike-slip fault which represents the zone of convergence between Laurussia/Laurentia and Avalon terranes. One or more of

440-533: Is coupled to the four tectophases of the Acadian orogeny, both in terms of provenance and depositional settings. The relief resulting from the orogeny was the fundamental source of the delta sediments. The Catskill Delta complex consists of a coarsening upward sequence of rocks. Its thickness is greatest in eastern Pennsylvania and thins westward into Ohio. The Catskill paleogeography appears to consist of many small streams, which deposited their sedimentary load along

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480-604: Is just offshore of the peninsula's eastern end. The peninsula's interior is a rugged northward continuation of the Appalachian Mountains called the Chic-Chocs , with Mount Jacques-Cartier at 1,268 metres (4,160 ft) the peninsula's highest peak. Mount Albert (Mont Albert) at 1,151 m (3,776 ft) is another high mountain in the Chic-Chocs. Its summit, an alpine area above the tree line ,

520-546: Is known as the Coastal Lithotectonic Block. The collision between Laurentia and Avalonian terranes is actually more complex than described above. The collision is broken into three or possibly four tectophases which represent a successive collision of the Avalonian terranes with eastern Laurentia. Because major clastic wedges and basinal deposits are distributed in a southwestward progression, it

560-555: Is poor and is found primarily in the plutonism of the Blue Ridge and metamorphism of the Cat Square terrane. The Acadian orogeny experienced at least three major phases of deformation, and in places, unconformities are recognized. These phases are called tectophases and represent the sequence of collisions that occurred from the Avalonian terranes accreting to Laurentia. As a result of these tectophases, deltas developed on

600-459: Is represented by regional uplift, which accompanied the collision of an Avalon terrane with a promontory, and subsequently, developed a regional disconformity . The fourth and final stage is represented by tectonic quiescence with a widespread carbonate deposition in a slowly transgressing sea. Gasp%C3%A9 Peninsula The Gaspé Peninsula , also known as Gaspesia ( French : Gaspésie , [ɡaspezi] ; Mi'kmaq : Gespe'gewa'ki ),

640-697: The Antler orogeny of the Great Basin . During the time of the Acadian orogeny, Middle Devonian (385 Ma), the paleolatitude of the Laurentia was in the southern hemisphere near the equator, between 0° to 30°S latitude. Laurentia did not change much with respect to paleolatitude during the Devonian. Gondwana , on the other hand, traveled a large distance, such that in the Ordovician the South Pole

680-599: The Carboniferous approximately 340 million years ago, and complete by the beginning of the Permian around 295 million years ago, when the range was at its maximum elevation. During the Permian, the mountain range was subjected to intense physical and mechanical weathering , reducing the peaks to around half their original size by the Late Permian ( Lopingian ) and creating numerous deep intermontane valleys. By

720-600: The Chic-Choc Mountains , part of the Notre Dame Mountains , an extension of the Appalachian Mountains . The town of Murdochville , at about 660 metres (2,170 ft) above sea level, has had a varied history, and is now home to several wind turbines . It is reached by Route 198 , which extends inland from the northern shore of the peninsula, soon climbing into the mountains and entering vast forests, crossing several small rivers before reaching

760-542: The Gaspé Peninsula , northern New Brunswick, and northern New England. Clastic wedges were present in this area, but the evidence for them has been mostly destroyed by succeeding tectonism. The second tectophase, during the Middle Devonian, represents the collision with the New York promontory. The southward migration of deformation reflected the third tectophase, which marks the collision of Avalon terranes with

800-755: The Middle Triassic , the Central Pangean mountains had been substantially reduced in size, and by the earliest Jurassic around 200 million years ago the Pangean range in Western Europe had been reduced to a few upland areas surrounded by deep marine basins . Climate modeling suggests that the Central Pangean Mountains contributed to the deposition of vast quantities of coal in the late Carboniferous. The mountains created an area of year-round heavy precipitation, with no dry season typical of

840-791: The Rheic Ocean , during the Middle to Late Devonian, and subsequently its closure resulted in the formation of the Alleghanian orogeny . Laurentia is the North American paleocontinent , which also includes present day northwest Ireland , Scotland , Greenland , the north slope of Alaska , and the Chukotsk Peninsula of northeastern Russia . During the Ordovician-Devonian time, Laurentia remained at

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880-545: The Triassic period is a stub . You can help Misplaced Pages by expanding it . Acadian orogeny The Acadian orogeny is a long-lasting mountain building event which began in the Middle Devonian , reaching a climax in the Late Devonian. It was active for approximately 50 million years, beginning roughly around 375 million years ago (Ma), with deformational, plutonic , and metamorphic events extending into

920-670: The Acadian foreland basin as a response to the Acadian orogeny. These deposits extend from central New York and Pennsylvania westward to Ohio, and south along the Appalachian Mountains through Virginia and Tennessee to Alabama. The Acadian delta complex is categorized into two deltas, the Catskill Delta of Middle and Upper Devonian age, and the Price-Rockwell in the Pocono Mountains delta of Late Devonian and Early Mississippian age. The Acadian delta complex

960-583: The Acadian orogeny extended from the Canadian Maritime provinces migrating in a southwesterly direction toward Alabama. However, the northern Appalachian region, from New England northeastward into Gaspé region of Canada, was the most greatly affected region by the collision. It was roughly contemporaneous with the Bretonic phase of the Variscan orogeny of Laurussia, with metamorphic events in southwestern Texas and northern Mexico , and with

1000-475: The Acadian orogeny, since it demonstrated an unusually long duration (Mississippian-Early Pennsylvanian). Subsequently, the Pocono and equivalent clastic wedges essentially filled the epicontinental sea . The deposition of Middle Mississippian carbonates marks the end of the Acadian orogeny and Catskill Delta complex. Foreland basins are a product of tectonic deformational loading, or crustal thickening along

1040-540: The Appalachian foreland basin at the onset of the Acadian orogeny were reactivated during foreland lithospheric flexure . These structures affected the foreland basin evolution and sedimentation patterns, and the preexisting faults partitioned the basin into regions of fault-controlled uplift and depocenters . The Appalachian basin, during the Middle Devonian and Early Mississippian, is characterized by large volumes of deltaic sedimentary rocks that were deposited in

1080-401: The Avalonian terranes accreted with the eastern margin of Laurentia, most likely beginning in the late Early Devonian. The evidence for the Acadian orogeny is abundant and widespread in the northern Appalachians, recorded by the plutonism and the migration of the northern Appalachian deformation front toward the craton . In the central to southern Appalachians, evidence for the Acadian orogeny

1120-419: The Middle to Late Devonian resided around intermediate latitudes of about 50°S. The collision initiating the Acadian orogeny resulted in the closing of the southern Iapetus Ocean and the formation of a high mountain belt . After the Acadian collision took place, Gondwana began to retreat from Laurentia with the newly accreted Avalonian terranes left behind. As Gondwana moved away, a new ocean opened up,

1160-556: The New England region and shed fine-grained clastic material into an inland seaway that covered a large part of southern and central Appalachia. Today, portions of the ancient Avalonia landmass occur in scattered outcrop belts along the eastern margin of North America. One belt occurs in Newfoundland; another forms the bedrock of much of the coastal region of New England from eastern Connecticut to northern Maine , where it

1200-723: The Virginia promontory in the Middle to Late Devonian time. The effects of the New York and Virginia promontories together produced the Catskill Delta complex. As the migration of deformation continued southward along the fault zone, during the Early Mississippian time, the final collision occurred with the Alabama promontory . Ettensohn refers to the fourth tectophase as the Mississippian tectophase of

1240-425: The adjacent parts of the stable craton, eastern margin of Laurentia. These deltas are described as foreland-basin, delta-complex clastic wedges, which are responsible for the large volumes of sediment input into the Appalachian basin. The collision of Avalonia with Laurentia initiated a sequence of events where the older rocks were subjected to deformation , plutonism, metamorphism , and uplift that occurred over

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1280-438: The black shales were deposited, the migration of deformation continued southward, and regression dominated, particularly on the east side of the basin. As collision intensified, subsidence in the foreland basin declined, and sedimentation was replaced by an influx of calcareous silty shales and carbonates. These deposits reflect small transgressive-regressive cycles in a delta-front and delta platform environments. The third stage

1320-600: The early Mississippian . The Acadian orogeny is the third of the four orogenies that formed the Appalachian Mountains and subsequent basin . The preceding orogenies consisted of the Grenville and Taconic orogenies , which followed a rift/drift stage in the Neoproterozoic . The Acadian orogeny involved the collision of a series of Avalonian continental fragments with the Laurasian continent. Geographically,

1360-486: The eastern continental margin, and the resulting foreland-basin and clastic wedges . Avalonian terranes that constitute Avalonia are the following modern-day regions: northern France, Belgium (the Ardennes ), England , Wales , southeastern Ireland , eastern Newfoundland , Nova Scotia , southern New Brunswick and some coastal parts of New England . The basement consisted of Late Precambrian age arc rocks and

1400-584: The equator. Due to their immense size and orientation nearly parallel to the equator, during the Late Permian the Central Pangean Mountains created a rain shadow to the north of the range, blocking the monsoonal rains from the Southern Hemisphere, and contributed to the formation of the immense Zechstein salt deposits in Europe. This palaeogeography article is a stub . You can help Misplaced Pages by expanding it . This article related to

1440-471: The orogen, a consequence of overthrusting and folding . The Acadian foreland basin is categorized as a retroarc foreland basin , which occurs on the overriding continental lithosphere , adjacent to a foreland fold-thrust belt behind a continental margin arc. The initial result of loading is a bulge move out and uplift of the foreland, which generates a localized unconformity. The distributions of unconformities display an asymmetric pattern in relation to

1480-414: The promontories. Subsidence follows bulge movement and uplift and is produced on the cratonic side of the orogen due to regional isostatic adjustment to the load by the lithosphere. Once thrust propagation declines, substantial relief and drainage nets have had time to develop, and the as a resulting coarser clastic sediment is eroded and transported to the foreland basin. The basement structures of

1520-606: The same paleolatitude, slightly south of the equator in the southern hemisphere, with relatively the same paleolongitude. Major defining tectonic events include the Neoproterozoic rift sequence from the breakup of Grenville basement rocks, thermal subsidence related to the Early Cambrian to Middle Ordovician drift sequence during the opening of the Iapetus Ocean, the Appalachian accretionary events to

1560-493: The town. From Murdochville, Route 198 follows the York River to the city of Gaspé on the peninsula's eastern tip. The peninsula's economy has historically been focused on fishing, agriculture and forestry. But primary resource-based industries are suffering due to overfishing , overexploitation , and fewer numbers of farmers in business, forcing the region to move towards tourism and the services industry . The peninsula

1600-470: Was located in northern Africa , where it then moved west of southern Chile during the Silurian , and moved back to central Africa during the Devonian. However, more recent research, from Scotese & McKerrow, suggests that in Late Devonian, the South Pole was in north-central Argentina rather than northern Africa, which was supported with paleoclimatic evidence. The paleolatitude of Gondwana during

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