Misplaced Pages

#389610

89-599: The Abulog River or Abulug River is the 9th largest river system in the Philippines in terms of watershed size. It has an estimated drainage area of 3,372 square kilometres (1,302 sq mi) and a length of 196 kilometres (122 mi) from its source in the mountains of Apayao in the Cordillera Administrative Region. More than 90% of the drainage area of the river is located in Apayao province while

178-446: A basin they form centripetal or inland drainage pattern. A deranged drainage system is a drainage system in drainage basins where there is no coherent pattern to the rivers and lakes. These can form in areas with extensive limestone deposits, where surface streams can disappear into the groundwater via caves and subterranean drainage routes. They can also form in areas where there has been much geological disruption. A classic example

267-603: A central playa . An axial river existed in the Espanola Basin as early as 13 million years ago, reaching the Santo Domingo Basin by 6.9 million years ago. However, at this time, the river drained into a playa in the southern Albuquerque Basin where it deposited the Popotosa Formation . The upper reach of this river corresponded to the modern Rio Chama , but by 5 million years ago, an ancestral Rio Grande draining

356-504: A central high point. Volcanos usually have archetypal features on which this commonly develops are modest or hard domes pattern develops when streams flow in many general directions (meaning quite long-term) In India, the Amarkantak range and Ramgarh crater are most archetypal; and Dogu'a Tembien in Ethiopia . When the streams converge at a point, which is generally a depression or

445-406: A drainage system develops on a surface composed of 'younger' rocks, but due to denudation activities this surface of younger rocks is removed and the river continues to flow over a seemingly new surface, but one in fact made up of rocks of old geological formation. Dendritic drainage systems (from Greek δενδρίτης , dendrites , "of or like a tree") are not straight and are the most common form of

534-463: A fragile ecosystem known as the Southern Appalachian spruce–fir forest . Fraser fir rarely occurs below 5,500 ft (1,700 m), and becomes the dominant tree type at 6,200 ft (1,900 m). By contrast, balsam fir is found from near sea level to the tree line in the northern Appalachians, but ranges only as far south as Virginia and West Virginia in the central Appalachians, where it

623-713: A great thickness of sediment accumulated. Eventually, the tectonic forces pulling the two continents apart became so strong that an ocean formed off the eastern coast of the Laurentian margin. This was called the Iapetus Ocean and was the precursor of the modern Atlantic Ocean. The rocks of the Valley and Ridge province formed over millions of years, in the Iapetus. Shells and other hard parts of ancient marine plants and animals accumulated to form limey deposits that later became limestone. This

712-499: A name for the tribe and region spreading well inland to the north. Pánfilo de Narváez 's expedition first entered Apalachee territory on June 15, 1528, and applied the name. Now spelled "Appalachian", it is the fourth-oldest surviving European place-name in the US. After the 1540 expedition of Hernando de Soto , Spanish cartographers began to apply the name of the tribe to the mountains themselves. The first cartographic appearance of Apalchen

801-656: A new ocean opened up, the Rheic Ocean , during the Middle to Late Devonian, and subsequently its closure would result in the formation of the Alleghanian orogeny . As the continental plates moved closer together, fragments of oceanic crust, islands, and other continental masses collided with the eastern margin of ancestral North America. By this time, plants had appeared on land, followed by scorpions, insects, and amphibians. The ocean continued to shrink until, about 270 million years ago,

890-504: A number of deciduous rhododendrons (azaleas), and smaller heaths such as teaberry ( Gaultheria procumbens ) and trailing arbutus ( Epigaea repens ). The evergreen great rhododendron ( Rhododendron maximum ) is characteristic of moist stream valleys. These occurrences are in line with the prevailing acidic character of most oak forest soils. In contrast, the much rarer chinquapin oak ( Quercus muehlenbergii ) demands alkaline soils and generally grows where limestone rock

979-444: A number of serious insect and disease outbreaks. Among the most conspicuous is that of the introduced spongy moth ( Lymantria dispar ), which infests primarily oaks, causing severe defoliation and tree mortality. But it also has the benefit of eliminating weak individuals, and thus improving the genetic stock, as well as creating rich habitat of a type through accumulation of dead wood. Because hardwoods sprout so readily, this moth

SECTION 10

#1733084504390

1068-573: A single lower base level. An example of an integrated drainage is the area drained by the Rio Grande River . The sedimentary basins forming the modern Rio Grande Valley were not integrated into a single river system draining into the Gulf of Mexico until relatively recent geologic time. Instead, the basins formed by the opening of the Rio Grande rift were initially bolsons , with no external drainage and

1157-607: A swimming spot. With the river being sacred by many, especially the Isnag people . This article related to a river in the Philippines is a stub . You can help Misplaced Pages by expanding it . River system Per the lie of channels , drainage systems can fall into one of several categories, known as drainage patterns. These depend on the topography and geology of the land. All forms of transitions can occur between parallel, dendritic, and trellis patterns. A drainage system

1246-822: A tangential or greater concentric path along a belt of weak rock so, with others, a roughly traced out ring can be seen. It is best displayed by streams draining a maturely dissected structural dome or basin where erosion has exposed rimming sedimentary strata of greatly varying degrees of hardness, as in the Red Valley , which nearly encircles the domal structure of the Black Hills of South Dakota . Astroblemes and mud diapirs are also thought to be able to cause this kind of drainage pattern. Angular drainage patterns form where bedrock joints and faults intersect at angles other than rectangular drainage patterns. Angles can be more or less than 90 degrees. An integrated drainage

1335-539: A variety of oaks ( Quercus spp.), hickories ( Carya spp.) and, in the past, by the American chestnut ( Castanea dentata ). The American chestnut was virtually eliminated as a canopy species by the introduced fungal chestnut blight ( Cryphonectaria parasitica ), but lives on as sapling-sized sprouts that originate from roots, which are not killed by the fungus. In present-day forest canopies, chestnut has been largely replaced by oaks. The oak forests of

1424-483: Is a boreal species that forms a few high elevation outliers as far south as West Virginia. All of these species except white pine tend to occupy sandy, rocky, poor soil sites, which are mostly acidic in character. White pine, a large species valued for its timber, tends to do best in rich, moist soil, either acidic or alkaline in character. Pitch pine is also at home in acidic, boggy soil, and Table Mountain pine may occasionally be found in this habitat as well. Shortleaf pine

1513-429: Is a mature drainage system characteristic of arid climates. It is formed by coalescing of individual basins formerly separated by high ground, such as mountains or ridges. Headward erosion from a lower basin may breach the barrier, as may spilling over from a higher basin due to aggradation (accumulation of sediments in the basin). The effect of integration of a drainage system is to replace local higher base levels with

1602-542: Is described as accordant if its pattern correlates to the structure and relief of the landscape over which it flows. A discordant system or pattern does not correlate to the topography and geology of the area. Discordant drainage patterns are classified into two main types: antecedent and superimposed , while ante position drainage patterns combine the two. In antecedent drainage, a river's vertical incision ability matches that of land uplift due to tectonic forces. Superimposed drainage develops differently: initially,

1691-403: Is found at high elevations in the northern Appalachians, and in bogs as far south as Pennsylvania. The Appalachians are also home to two species of fir, the boreal balsam fir ( Abies balsamea ), and the southern high elevation endemic, Fraser fir ( Abies fraseri ). Fraser fir is endemic to the highest parts of the southern Appalachian Mountains, where along with red spruce it forms

1780-533: Is generally found in warmer habitats and at lower elevations than the other species. All the species listed do best in open or lightly shaded habitats, although white pine also thrives in shady coves, valleys, and on floodplains. The Appalachians are characterized by a wealth of large, beautiful deciduous broadleaf (hardwood) trees. Their occurrences are best summarized and described in E. Lucy Braun 's 1950 classic, Deciduous Forests of Eastern North America (Macmillan, New York). The most diverse and richest forests are

1869-414: Is near the surface. Hence no ericaceous shrubs are associated with it. The Appalachian flora also include a diverse assemblage of bryophytes (mosses and liverworts), as well as fungi . Some species are rare and/or endemic. As with vascular plants , these tend to be closely related to the character of the soils and the thermal environment in which they are found. Eastern deciduous forests are subject to

SECTION 20

#1733084504390

1958-519: Is not as harmful as the hemlock woolly adelgid . Perhaps more serious is the introduced beech bark disease complex, which includes both a scale insect ( Cryptococcus fagisuga ) and fungal components. During the 19th and early 20th centuries, the Appalachian forests were subject to severe and destructive logging and land clearing, which resulted in the designation of the national forests and parks as well many state-protected areas. However, these and

2047-470: Is now the southern United States, the Ococee Basin was formed. Seawater filled the basin. Rivers from the surrounding countryside carried clay, silt, sand, and gravel to the basin, much as rivers today carry sediment from the midcontinent region to the Gulf of Mexico. The sediment spread out in layers on the basin floor. The basin continued to subside, and over a long period of time, probably millions of years,

2136-525: Is on Diego Gutiérrez 's map of 1562; the first use for the mountain range is the map of Jacques le Moyne de Morgues in 1565. The name was not commonly used for the whole mountain range until the late 19th century. A competing and often more popular name was the "Allegheny Mountains", "Alleghenies", and even "Alleghania". In the early 19th century, Washington Irving proposed renaming the United States either Appalachia or Alleghania. In U.S. dialects in

2225-535: Is possible that the cratons of Kalahari , and Rio Plato , were also part of that early collision since they were present as Rodinia broke up). Mountain-building referred to as the Grenville Orogeny occurred along the boundaries of the cratons. The present Appalachian Mountains have at least two areas which are made from rock formations that were formed during this orogeny - the Blue Ridge Mountains and

2314-638: Is sometimes termed the Appalachian orogeny , writing communities struggle to agree on an encyclopedic definition of the mountain range. However, each of the governments has an agency that informs the public about the major landforms that make up the countries, the United States Geological Survey (USGS) and the Geological Survey of Canada (GSC). The landforms are referred to as physiographic regions. The regions create precise boundaries from which maps can be drawn. The Appalachian Highlands

2403-700: Is subject to the hemlock woolly adelgid ( Adelges tsugae ), an introduced insect, that is rapidly extirpating it as a forest tree. Less abundant, and restricted to the southern Appalachians, is Carolina hemlock ( Tsuga caroliniana ). Like Canada hemlock, this tree suffers severely from the hemlock woolly adelgid. Several species of pines characteristic of the Appalachians are eastern white pine ( Pinus strobus ), Virginia pine ( Pinus virginiana ), pitch pine ( Pinus rigida ), Table Mountain pine ( Pinus pungens ) and shortleaf pine ( Pinus echinata ). Red pine ( Pinus resinosa )

2492-491: Is the Canadian Shield . During the last ice age , the topsoil was scraped off, leaving mostly bare rock. The melting of the glaciers left land with many irregularities of elevation and a great deal of water to collect in the low points, resulting in the region's many lakes. The drainage basins are young and are still sorting themselves out; eventually the system will stabilize. In an annular drainage pattern, streams trace

2581-456: Is the name of one of the eight physiographic regions of the contiguous 48 United States. The Appalachian Uplands is the name of one of seven physiographic regions of Canada. The second level in the physiographic classification schema for the USGS is "province", the same word as Canada uses to divide its political subdivisions, meaning that the terminology used by the two countries do not match below

2670-506: Is the same process by which limestone forms in modern oceans. The weathering of limestone, now exposed at the land surface, produces the lime-rich soils that are so prevalent in the fertile farmland of the Valley and Ridge province. During this continental break-up, around 600 million to 560 million years ago, volcanic activity was present along the tectonic margins. There is evidence of this activity in today's Blue Ridge Mountains. Mount Rogers , Whitetop Mountain , and Pine Mountain are all

2759-459: Is usually confined above 3,900 ft (1,200 m) asl, except in cold valleys. Curiously, it is associated with oaks in Virginia. The balsam fir of Virginia and West Virginia is thought by some to be a natural hybrid between the more northern variety and Fraser fir. While red spruce is common in both upland and bog habitats, balsam fir, as well as black spruce and tamarack, are more characteristic of

Abulog - Misplaced Pages Continue

2848-611: The Adirondacks . After the Grenville orogeny, the direction of the continental drift reversed, and the single supercontinent Rodinia began to break up. The mountains formed during the Grenvillian era underwent erosion due to weathering, glaciation, and other natural processes, resulting in the leveling of the landscape. The eroded sediments from these mountains contributed to the formation of sedimentary basins and valleys. For example, in what

2937-509: The Alps and the Rockies before natural erosion occurred over the last 240 million years leading to what is present today. The Appalachian Mountains are a barrier to east–west travel, as they form a series of alternating ridgelines and valleys oriented in opposition to most highways and railroads running east–west. This barrier was extremely important in shaping the expansion of the United States in

3026-465: The Appalachians , are a mountain range in eastern to northeastern North America . The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain. The general definition used is one followed by the United States Geological Survey and the Geological Survey of Canada to describe the respective countries' physiographic regions. The U.S. uses

3115-581: The Coal Region of northeastern Pennsylvania . The bituminous coal fields of western Pennsylvania , western Maryland , southeastern Ohio, eastern Kentucky, southwestern Virginia , and West Virginia contain the sedimentary form of coal. The mountain top removal method of coal mining , in which entire mountain tops are removed, is currently threatening vast areas and ecosystems of the Appalachian Mountain region. The surface coal mining that started in

3204-723: The Gulf of Mexico . In the central section, north of the New River, the rivers, rising in or just beyond the Valley Ridges, flow through great gorges to the Great Valley, and then across the Blue Ridge to tidal estuaries penetrating the coastal plain via the Roanoke River, James River , Potomac River , and Susquehanna River . In the northern section the height of land lies on the inland side of

3293-704: The Iapetus Ocean , from the North America/Europe collision (See Caledonian orogeny ). By the end of the Mesozoic Era , the Appalachian Mountains had been eroded to an almost flat plain. It was not until the region was uplifted during the Cenozoic Era that the distinctive topography of the present formed. Uplift rejuvenated the streams, which rapidly responded by cutting downward into the ancient bedrock. Some streams flowed along weak layers that define

3382-484: The North American craton . Volcanoes grew along the continental margin coincident with the initiation of subduction . Thrust faulting uplifted and warped older sedimentary rock laid down on the passive margin. As the mountains rose, erosion began to wear them down over time. Streams carried rock debris downslope to be deposited in nearby lowlands. The Taconic orogeny ended after about 60 million years, but built much of

3471-543: The Rocky Mountains of the west. Some of the outcrops in the Appalachians contain rocks formed during the Precambrian era. The geologic processes that led to the formation of the Appalachian Mountains started 1.1 billion years ago. The first mountain range in the region was created when the continents of Laurentia and Amazonia collided, creating a supercontinent called Rodinia . The collision of these continents caused

3560-706: The eastern seaboard of the United States and the Midwest region of the country. The Eastern Continental Divide follows the Appalachian Mountains from Pennsylvania to Georgia. The Appalachians, particularly the Central and Southern regions, is one of the most biodiverse places in North America. The north–south orientation of the long ridges and valleys contributes to the high number of plant and animal species. Species were able to migrate through these from either direction during alternating periods of warming and cooling, settling in

3649-1546: The mixed-mesophytic or medium-moisture types, which are largely confined to rich, moist montane soils of the southern and central Appalachians, particularly in the Cumberland and Allegheny Mountains, but also thrive in the southern Appalachian coves. Characteristic canopy species are white basswood ( Tilia heterophylla ), yellow buckeye ( Aesculus octandra ), sugar maple ( Acer saccharum ), American beech ( Fagus grandifolia ), tuliptree ( Liriodendron tulipifera ), white ash ( Fraxinus americana ) and yellow birch ( Betula alleganiensis ). Other common trees are red maple ( Acer rubrum ), shagbark and bitternut hickories ( Carya ovata and C. cordiformis ) and black or sweet birch ( Betula lenta ). Small understory trees and shrubs include paw paw ( Asimina tribola ), flowering dogwood ( Cornus florida ), hophornbeam ( Ostrya virginiana ), witch-hazel ( Hamamelis virginiana ) and spicebush ( Lindera benzoin ). There are also hundreds of perennial and annual herbs, among them such herbal and medicinal plants as American ginseng ( Panax quinquefolius ), goldenseal ( Hydrastis canadensis ), bloodroot ( Sanguinaria canadensis ) and black cohosh ( Cimicifuga racemosa ). The foregoing trees, shrubs, and herbs are also more widely distributed in less rich mesic forests that generally occupy coves, stream valleys and flood plains throughout

Abulog - Misplaced Pages Continue

3738-581: The 1940s has significantly impacted the central Appalachian Mountains in Kentucky , Tennessee , Virginia and West Virginia. Early mining methods were unregulated and mined land reclamation research, including acid base reaction , was led by the West Virginia University in the 1960s and 1970s. West Virginia developed rigorous mine reclamation standards for state coal mines in the late 1960s. Regulations were introduced by most federal states to protect

3827-553: The 96-square-mile (248.6 km ) archipelago of Saint Pierre and Miquelon , an overseas collectivity of France , meaning it is technically in three countries. The highest peak of the mountain range is Mount Mitchell in North Carolina at 6,684 feet (2,037 m), which is also the highest point in the United States east of the Mississippi River . The range is older than the other major mountain range in North America,

3916-546: The Appalachian Basin. Some plateaus of the Appalachian Mountains contain metallic minerals such as iron and zinc . There are many geological issues concerning the rivers and streams of the Appalachians. In spite of the existence of the Great Appalachian Valley, many of the main rivers are transverse to the mountain system axis. The drainage divide of the Appalachians follows a tortuous course that crosses

4005-610: The Appalachian Mountains by the late 1960s. Social and political activism brought about the Surface Mining Control and Reclamation Act of 1977 . The 1859 discovery of commercial quantities of petroleum in the Appalachian Mountains of western Pennsylvania started the modern United States petroleum industry . Recent discoveries of commercial natural gas deposits in the Marcellus Shale formation and Utica Shale formations have once again focused oil industry attention on

4094-588: The Appalachian range in New Brunswick and Quebec . While exploring inland along the northern coast of Florida in 1528, the members of the Narváez expedition , including Álvar Núñez Cabeza de Vaca , found a Native American village near present-day Tallahassee, Florida whose name they transcribed as Apalchen or Apalachen [a.paˈla.tʃɛn] . The name was soon altered by the Spanish to Apalachee and used as

4183-536: The Blue Ridge again reaches 2,000 ft (600 m) and higher. In the Virginia Blue Ridge, the following are some of the highest peaks north of the Roanoke River : Stony Man 4,031 ft (1,229 m), Hawksbill Mountain 4,066 ft (1,239 m), Apple Orchard Mountain 4,225 ft (1,288 m) and Peaks of Otter 4,001 and 3,875 ft (1,220 and 1,181 m). South of the Roanoke River, along

4272-708: The Blue Ridge, are Virginia's highest peaks including Whitetop Mountain 5,520 ft (1,680 m) and Mount Rogers 5,729 ft (1,746 m), the highest point in the Commonwealth. Chief summits in the southern section of the Blue Ridge are located along two main crests, the Western or Unaka Front along the Tennessee - North Carolina border and the Eastern Front in North Carolina, or one of several "cross ridges" between

4361-883: The Great Balsams. The Western Blue Ridge Front is subdivided into the Unaka Range , the Bald Mountains , the Great Smoky Mountains , and the Unicoi Mountains , and its major peaks include Roan Mountain 6,285 ft (1,916 m) in the Unakas, Big Bald 5,516 ft (1,681 m) and Max Patch 4,616 ft (1,407 m) in the Bald Mountains, Kuwohi 6,643 ft (2,025 m), Mount Le Conte 6,593 feet (2,010 m), and Mount Guyot 6,621 ft (2,018 m) in

4450-727: The Great Smokies, and Big Frog Mountain 4,224 ft (1,287 m) near the Tennessee- Georgia -North Carolina border. Prominent summits in the cross ridges include Waterrock Knob (6,292 ft (1,918 m)) in the Plott Balsams . Across northern Georgia, numerous peaks exceed 4,000 ft (1,200 m), including Brasstown Bald , the state's highest, at 4,784-and-4,696 ft (1,458-and-1,431 m) Rabun Bald . In north-central Alabama , Mount Cheaha rises prominently to 1,445 feet (440 m) over its surroundings, as part of

4539-510: The San Luis basin until a spillover event 440,000 years ago that drained Lake Alamosa and fully reintegrated the San Luis basin into the Rio Grande basin. Integrated drainages were widespread in western North America in the Paleocene and Eocene , and there is evidence of integrated drainages on the surface of Mars . Appalachian Mountains The Appalachian Mountains , often called

SECTION 50

#1733084504390

4628-579: The U.S./Canadian border, the St. Lawrence Valley area is handled differently in the physiographic classification schemas. The part of the St. Lawrence Valley in the United States is one of the second-level classifications, part of the Appalachian Highlands. In Canada, the area is part of the first-level classification, the St. Lawrence Lowlands . This includes the area around the city of Montreal, Anticosti Island , and

4717-501: The bulk rock so erosion tends to preferentially open the joints and streams eventually develop along the joints. The result is a stream system in which streams consist mainly of straight line segments with right-angle bends and tributaries join larger streams at right angles. This pattern can be found with the Arun River in Nepal. In a radial drainage system, the streams radiate outwards from

4806-619: The colonial era. The range is the home of a very popular recreational feature, the Appalachian Trail . This is a 2,175-mile (3,500 km) hiking trail that runs all the way from Mount Katahdin in Maine to Springer Mountain in Georgia , passing over or past a large part of the Appalachian range. The International Appalachian Trail is an extension of this hiking trail into the Canadian portion of

4895-457: The continent that are now exposed. The first mountain-building tectonic plate collision that initiated the construction of what are today the Appalachians occurred at least a billion years ago when the pre-North American craton called Laurentia collided with at least one other craton - Amazonia . All the other cratons of the earth also collided at about this time to form the supercontinent Rodinia and were surrounded by one single ocean. (It

4984-416: The continents that were ancestral to North America and Africa collided during the formation of the supercontinent Pangea . Because North America and Africa were once geographically connected, the Appalachians formed part of the same mountain chain as the Little Atlas in Morocco . This mountain range, known as the Central Pangean Mountains , extended into Scotland , before the Mesozoic Era opening of

5073-412: The deciduous needle-leaf conifer, the tamarack , or eastern larch ( Larix laricina ). The dominant northern and high elevation conifer is the red spruce ( Picea rubens ), which grows from near sea level to above 4,000 ft (1,200 m) above sea level (asl) in northern New England and southeastern Canada. It also grows southward along the Appalachian crest to the highest elevations of

5162-699: The drainage system. In this, there are many sub-tributaries (analogous to the twigs of a tree), which merge into tributaries of the main river (the branches and the trunk of the tree, respectively). They are seen to feed a river channel that matches and is strongly accordant to the overriding gradient of the land. Truly dendritic systems form in V-shaped valleys ; as a result, the rock types must be impervious and non-porous . A parallel drainage system occurs on elongate landforms like outcropping resistant rock bands), typically following natural faults or erosion (such as prevailing wind scars). The watercourses run swift and straight, with very few tributaries, and all flow in

5251-529: The driest sites are dominated by chestnut oak, or sometimes by scarlet or northern red oaks. In the northern Appalachians the oaks, except for white and northern red, drop out, while the latter extends farthest north. The oak forests generally lack the diverse small tree, shrub and herb layers of mesic forests. Shrubs are generally ericaceous , and include the evergreen mountain laurel ( Kalmia latifolia ), various species of blueberries ( Vaccinium spp.), black huckleberry ( Gaylussacia baccata ),

5340-406: The eastern San Juan Mountains had joined the ancestral Rio Chama. The ancestral Rio Grande progressively integrated basins to the south, reaching the Palomas basin by 4.5 million years ago, the Mesilla basin by 3.1 million years, to Texas by 2.06 million years, and finally joining the Pecos River at 800,000 years to drain into the Gulf of Mexico. Volcanism in the Taos Plateau reduced drainage from

5429-425: The folds and faults created many millions of years earlier. Other streams downcut so rapidly that they cut right across the resistant folded rocks of the mountain core, carving canyons across rock layers and geologic structures. The Appalachian Mountains contain major deposits of anthracite coal as well as bituminous coal . In the folded mountains the coal is in metamorphosed form as anthracite , represented by

SECTION 60

#1733084504390

5518-431: The land mass that is now New England and southwestward to Pennsylvania. The Taconic Orogeny was the second of four mountain building plate collisions that contributed to the formation of the Appalachians, culminating in the collision of North America and Africa (see Alleghanian orogeny ). The third mountain-building event was the Acadian orogeny which occurred between 375 and 359 million years ago. The Acadian orogeny

5607-469: The latter. However, balsam fir also does well in soils with a pH as high as 6. Eastern or Canada hemlock ( Tsuga canadensis ) is another important evergreen needle-leaf conifer that grows along the Appalachian chain from north to south but is confined to lower elevations than red spruce and the firs. It generally occupies richer and less acidic soils than the spruce and firs and is characteristic of deep, shaded and moist mountain valleys and coves . It

5696-456: The microclimates that best suited them. The flora of the Appalachians are diverse and vary primarily in response to geology, latitude, elevation and moisture availability. Geobotanically, they constitute a floristic province of the North American Atlantic Region . The Appalachians consist primarily of deciduous broad-leaf trees and evergreen needle-leaf conifers, but also contain the evergreen broad-leaf American holly ( Ilex opaca ), and

5785-433: The more notable peaks in West Virginia. The Blue Ridge Mountains , rising in southern Pennsylvania and there known as South Mountain , attain elevations of about 2,000 ft (600 m) in Pennsylvania. South Mountain achieves its highest point just below the Mason-Dixon line in Maryland at Quirauk Mountain 2,145 ft (654 m) and then diminishes in height southward to the Potomac River . Once in Virginia ,

5874-406: The mountainous belt just north of the New River in Virginia. South of the New River, rivers head into the Blue Ridge, cross the higher Unakas, receive important tributaries from the Great Valley, and traversing the Cumberland Plateau in spreading gorges ( water gaps ), escape by way of the Cumberland River and the Tennessee River rivers to the Ohio River and the Mississippi River, and thence to

5963-429: The mountainous belt, and thus the main lines of drainage run from north to south, exemplified by the Hudson River . However, the valley through which the Hudson River flows was cut by the gigantic glaciers of the ice ages —the same glaciers that deposited their terminal moraines in southern New York and formed the east–west Long Island . The Appalachian region is generally considered the geographical divide between

6052-531: The northwest coastline of Newfoundland. The dissected plateau area, while not actually made up of geological mountains, is popularly called "mountains", especially in eastern Kentucky and West Virginia, and while the ridges are not high, the terrain is extremely rugged. In Ohio and New York, some of the plateau has been glaciated , which has rounded off the sharp ridges and filled the valleys to some extent. The glaciated regions are usually referred to as hill country rather than mountains. The Appalachian belt includes

6141-424: The oceans, but there were no plants or animals on land. Then, during the middle Ordovician Period about 500 to 470 million years ago, the motion of the crustal plates changed, and the continents began to move back toward each other. The once-quiet Appalachian passive margin changed to a very active plate boundary when a neighboring Iapetus oceanic plate containing a volcanic arc collided with and began sinking beneath

6230-423: The plateaus sloping southward to the Atlantic Ocean in New England , and southeastward to the border of the coastal plain through the central and southern Atlantic states; and on the northwest, the Allegheny and Cumberland plateaus declining toward the Great Lakes and the interior plains. A remarkable feature of the belt is the longitudinal chain of broad valleys, including the Great Appalachian Valley , which in

6319-478: The region level. The lowest level of classification is "section". The Appalachian Uplands are one of the seven physiographic divisions in Canada . Canada's GSC does not use the same classification system as the USGS below the division level. The agency does break the divisions of the Appalachian Uplands into 13 subsections that are in four different political provinces of Canada. While the Appalachian Highlands and Appalachian Uplands are generally continuous across

6408-652: The remaining, including the mouth of the river , is in Cagayan province. The river is located in the northern part of Cordillera , along with the Apayao River . The river is part of the Abulog-Apayao basin, which spans at about a 444,500 hectares (1,716 sq mi) size. The upper reaches of the Abulug River, especially upstream from Kabugao , is commonly known as the Apayao River . Development plans were proposed for

6497-454: The residents of the regions regarding the correct pronunciation. Elsewhere, a commonly accepted pronunciation for the adjective Appalachian is / ˌ æ p ə ˈ l æ tʃ i ə n / , with the last two syllables "-ian" pronounced as in the word "Romanian". Perhaps partly because the range runs through large portions of both the United States and Canada, and partly because the range was formed over numerous geologic time periods, one of which

6586-482: The result of volcanic activity that occurred around this time. Evidence of subsurface activity, dikes and sills intruding into the overlying rock, is present in the Blue Ridge as well. For instance, mafic rocks have been found along the Fries Fault in the central Blue Ridge area of Montgomery County, VA. The Iapetus continued to expand and during that time bacteria, algae, and many species of invertebrates flourished in

6675-557: The river, for creating a dam, or more specifically four. The Gened 2 HEPP, the Aoan Dam, the Calanasan dam, and one more unnamed dam. The council still needs to get permission from the Isnag people to construct the dams. The reactions were mixed, with elders liking the project, stating that it will “will uplift the lives of so many generations to come.” The river is used by many as a fishing spot and

6764-466: The rocks to be folded and faulted, creating the first mountains in the region. Many of the rocks and minerals that were formed during that event can currently be seen at the surface of the present Appalachian range. Around 480 million years ago, geologic processes began that led to three distinct orogenic eras that created much of the surface structure seen in today's Appalachians. During this period, mountains once reached elevations similar to those of

6853-527: The same direction. This system forms on very long, uniform slopes, for instance, high rivers flowing southeast from the Aberdare Mountains in Kenya and many rivers of Myanmar . This sometimes indicates a major fault that cuts across an area of steeply folded bedrock. The geometry of a trellis drainage system is similar to that of a common garden trellis . Along a strike valley, smaller tributaries feed into

6942-706: The same side of the Great Valley, south of the Potomac, are the Pinnacle 3,007 feet (917 m) and Pidgeon Roost 3,400 ft (1,000 m). In West Virginia, more than 150 peaks rise above 4,000 ft (1,200 m), including Spruce Knob 4,863 ft (1,482 m), the highest point in the Allegheny Mountains . A number of other points in the state rise above 4,800 ft (1,500 m). Cheat Mountain ( Snowshoe Mountain ) at Thorny Flat 4,848 ft (1,478 m) and Bald Knob 4,842 ft (1,476 m) are among

7031-409: The same trend as the system itself. None of the summits reaches the region of perpetual snow. In Pennsylvania , there are over sixty summits that rise over 2,500 ft (800 m); the summits of Mount Davis and Blue Knob rise over 3,000 ft (900 m). In Maryland, Eagle Rock and Dans Mountain are conspicuous points reaching 3,162 and 2,882 ft (964 and 878 m) respectively. On

7120-481: The southerly sections divides the mountain system into two unequal portions, but in the northernmost lies west of all the ranges possessing typical Appalachian features, and separates them from the Adirondack group. The mountain system has no axis of dominating altitudes, but in every portion, the summits rise to rather uniform heights, and, especially in the central section, the various ridges and intermontane valleys have

7209-416: The southern Appalachians, as in North Carolina and Tennessee . In the central Appalachians it is usually confined above 3,000 ft (900 m) asl, except for a few cold valleys in which it reaches lower elevations. In the southern Appalachians, it is restricted to higher elevations. Another species is the black spruce ( Picea mariana ), which extends farthest north of any conifer in North America,

7298-413: The southern and central Appalachians consist largely of black , northern red , white , chestnut and scarlet oaks ( Quercus velutina, Q. rubra, Q. alba, Q. prinus and Q. coccinea ) and hickories, such as the pignut ( Carya glabra ) in particular. The richest forests, which grade into mesic types, usually in coves and on gentle slopes, have predominantly white and northern red oaks, while

7387-511: The southern and central Appalachians at low and intermediate elevations. In the northern Appalachians and at higher elevations of the central and southern Appalachians these diverse mesic forests give way to less diverse northern hardwood forests with canopies dominated only by American beech, sugar maple, American basswood ( Tilia americana ) and yellow birch and with far fewer species of shrubs and herbs. Drier and rockier uplands and ridges are occupied by oak–chestnut forests dominated by

7476-410: The southern regions of the Appalachians, the word is pronounced / ˌ æ p ə ˈ l æ tʃ ɪ n z / , with the third syllable sounding like "latch". In northern parts of the mountain range, it is pronounced / ˌ æ p ə ˈ l eɪ tʃ ɪ n z / or / ˌ æ p ə ˈ l eɪ ʃ ɪ n z / ; the third syllable is like "lay", and the fourth "chins" or "shins". There is often great debate between

7565-535: The southernmost spur of the Blue Ridge Mountains. Sources written prior to the recognition of the concept of physiographic regions divided the Appalachian Mountains into three major sections: Plate tectonics over the period dating back at least 1 billion years led to geological creation of the land that is now the Appalachian Mountain range. The continental movement led to collisions that built mountains and they later pulled apart creating oceans over parts of

7654-730: The steep slopes of mountainsides. These tributaries enter the main river about perpendicular, causing a trellis-like appearance of the system. They form where hard and soft formations exist on both banks of the main river, and are reflective of height, accentuated by erosion. Trellis drainage is characteristic of folded mountains, such as the Appalachian Mountains in North America and in the north part of Trinidad . Rectangular drainage develops on rocks that are of approximately uniform resistance to erosion , but which have two directions of jointing at approximately right angles or 90 degrees. The joints are usually less resistant to erosion than

7743-573: The term Appalachian Highlands and Canada uses the term Appalachian Uplands ; the Appalachian Mountains are not synonymous with the Appalachian Plateau , which is one of the provinces of the Appalachian Highlands. The Appalachian range runs from the Island of Newfoundland in Canada, 2,050 mi (3,300 km) southwestward to Central Alabama in the United States; south of Newfoundland, it crosses

7832-607: The two main crests. Major subranges of the Eastern Front include the Black Mountains , Great Craggy Mountains , and Great Balsam Mountains , and its chief summits include Grandfather Mountain 5,964 ft (1,818 m) near the Tennessee-North Carolina border, Mount Mitchell 6,684 ft (2,037 m) in the Blacks, and Black Balsam Knob 6,214 ft (1,894 m) and Cold Mountain 6,030 ft (1,840 m) in

7921-639: Was caused by a series of collisions of pieces of crust from the Avalonia Terrane, sections broken off from continent of Gondwana , with the North American Plate. The collision initiating this 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,

#389610