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81-548: The oldest portions of the range are over 60 million years old, with volcanics and a forearc basin as the primary mountain building processes responsible for the range. It is part of the larger grouping known as the Pacific Coast Ranges that extends over much of the western edge of North America from California to Alaska. The range creates a rain shadow effect for the Willamette Valley that lies to

162-486: A tectonic plate that poses a continued threat of volcanic activity and earthquakes in the region. The most recent major activity was the 1700 Cascadia earthquake . Washington 's Mount St. Helens erupted in 1980 , an event visible from northern Oregon and affecting some areas there. The Columbia River, which forms much of Oregon's northern border, also played a major role in the region's geological evolution, as well as its economic and cultural development. The Columbia

243-581: A "g". Another possible source is the Spanish word oregano , which refers to a plant that grows in the southern part of the region. It is also possible that the area around the Columbia River was named after a stream in Spain called "Arroyo del Oregón", located in the province of Ciudad Real . Another early use of the name, spelled Ouragon , was by Major Robert Rogers in a 1765 petition to

324-448: A forearc basin(s), outer-arc high, accretionary prism and the trench itself. The forearc subduction interface can include a seismogenic zone, where megathrust earthquakes can occur, a decoupled zone, and a viscously coupled zone. The accretionary prism is located at the slope of the trench break where there is significantly decreased slope angle. Between the break and the magmatic arc, a sedimentary basin filled with erosive material from

405-490: A heat flow of ~30–40 mW/m , which indicates cold, strong mantle. One good example is the Mariana forearc, where scientists have done extensive research. In this setting there is an erosive margin and forearc slope which consists of 2 km high and 30 km diameter serpentine- mud volcanoes . The erosive properties of these volcanoes are consistent with the metamorphic grades (blueschists) expected for this region in

486-443: A hot basalt flow rapidly cooled upon meeting the salt water of the ocean. These deposits offshore were then pushed into the continental plate as a forearc basin rotating slowly over millions of years. This tectonic collision forced the basalt formations (and newer sedimentary rock formations that include marine terrace deposits) upward and created the coastal range. Additional basalt flows originated from Eastern Oregon and added to

567-510: A probate government was proposed. Doctor Ira Babcock of Jason Lee 's Methodist Mission was elected supreme judge. Babcock chaired two meetings in 1842 at Champoeg , (halfway between Lee's mission and Oregon City ), to discuss wolves and other animals of contemporary concern. These meetings were precursors to an all-citizen meeting in 1843, which instituted a provisional government headed by an executive committee made up of David Hill , Alanson Beers , and Joseph Gale . This government

648-622: A railroad in 1851 from St. Helens, through the Cornelius pass and across Washington County to the city of Lafayette, which was at the time the big town of the Willamette Valley. In December 1844, Oregon passed its first black exclusion law , which prohibited African Americans from entering the territory while simultaneously prohibiting slavery . Slave owners who brought their slaves with them were given three years before they were forced to free them. Any African Americans in

729-586: A refuge from disputes over slavery, Oregon had a "whites only" clause in its original state Constitution. At the outbreak of the American Civil War , regular U.S. troops were withdrawn and sent east to aid the Union . Volunteer cavalry recruited in California were sent north to Oregon to keep peace and protect the populace. The First Oregon Cavalry served until June 1865. Beginning in the 1880s,

810-474: A section of the larger Pacific Border province, which in turn are part of the larger Pacific Mountain System physiographic division. A mild maritime climate prevails throughout the range with temperature and precipitation varying due to elevation and distance from the coastline. Characteristics of the climate include cool dry summers followed by mild and wet winters. The majority of precipitation accumulates in

891-550: A água , Oregon. Yet another account, endorsed as the "most plausible explanation" in the book Oregon Geographic Names , was advanced by George R. Stewart in a 1944 article in American Speech . According to Stewart, the name came from an engraver's error in a French map published in the early 18th century, on which the Ouisiconsink (Wisconsin) River was spelled " Ouaricon-sint ", broken on two lines with

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972-535: Is a major industry in the range in both private and government owned forests. Both the state and federal government manage forests in the Oregon Coast Range. The mountains are home to a variety of wildlife including black bear, elk, deer, beaver, many species of birds, and bats among others. Fish, including salmon and trout, and other aquatic life inhabit the streams and rivers flowing through the range. Volcanic activity approximately 66 million years ago in

1053-949: Is bounded by the Willamette Valley on the east and the Pacific Ocean to the west. This approximately 90-mile (140 km) long mountain range contains mountains as high as 4,097 feet (1,248 m) for Marys Peak . Portions of the range are inside the Siuslaw National Forest along with three designated wilderness areas: Drift Creek Wilderness , Cummins Creek Wilderness and the Rock Creek Wilderness . Larger animals that live in these section include deer, elk, bobcat, and bear. Bear are black bear while deer are mule and black-tailed deer species. Other mammals here are mountain beaver , beavers, coyote, mink, river otter , mountain lion, porcupines, skunks, and brush rabbit. The southernmost section of

1134-425: Is constant recycling of the forearc deposits due to erosion, deformation and sedimentary subduction. The constant circulation of material in the forearc region (accretionary prism, forearc basin and trench) generates a mixture of igneous, metamorphic and sedimentary sequences. In general, there is an increase in metamorphic grade from trench to arc where highest grade (blueschist to eclogite) is structurally uplifted (in

1215-472: Is evidence supporting inhabitants in the region at least 15,000 years ago. By 8000 BC, there were settlements throughout the state, with populations concentrated along the lower Columbia River, in the western valleys, and around coastal estuaries. During the prehistoric period , the Willamette Valley region was flooded after the collapse of glacial dams from then Lake Missoula , located in what would later become Montana . These massive floods occurred during

1296-461: Is in this region of the state. Typical of a western state, Oregon is home to a unique and diverse array of wildlife. Roughly 60 percent of the state is covered in forest, while the areas west of the Cascades are more densely populated by forest, making up around 80 percent of the landscape. Some 60 percent of Oregon's forests are within federal land. Oregon is the top timber producer of

1377-839: Is now Oregon's Pacific coast in the early to mid-16th century. As early as 1564, the Spanish began sending vessels northeast from the Philippines , riding the Kuroshio Current in a sweeping circular route across the northern part of the Pacific. In 1592, Juan de Fuca undertook detailed mapping and studies of ocean currents in the Pacific Northwest, including the Oregon coast as well as the strait now bearing his name. The Lewis and Clark Expedition traversed Oregon in

1458-473: Is now allowed in Oregon, gas stations are not required to offer it and many currently do not. New Jersey is the only state remaining where self serve gas stations are not allowed. Oregon is 295 miles (475 km) north to south at longest distance, and 395 miles (636 km) east to west. With an area of 98,381 square miles (254,810 km ), Oregon is slightly larger than the United Kingdom . It

1539-730: Is one of North America's largest rivers, and one of two rivers to cut through the Cascades (the Klamath River in southern Oregon is the other). About 15,000 years ago, the Columbia repeatedly flooded much of Oregon during the Missoula Floods ; the modern fertility of the Willamette Valley is largely the result. Plentiful salmon made parts of the river, such as Celilo Falls , hubs of economic activity for thousands of years. Today, Oregon's landscape varies from rain forest in

1620-487: Is probable some still move into eastern Oregon from Idaho. Oregon is home to what is considered the largest single organism in the world, an Armillaria solidipes fungus beneath the Malheur National Forest of eastern Oregon. Oregon has several National Park System sites , including Crater Lake National Park in the southern part of the Cascades, John Day Fossil Beds National Monument east of

1701-460: Is rounded down phonetically, from Ouve água —Oragua, Or-a-gon, Oregon—given probably by the same Portuguese navigator that named the Farallones after his first officer, and it literally, in a large way, means cascades: "Hear the waters." You should steam up the Columbia and hear and feel the waters falling out of the clouds of Mount Hood to understand entirely the full meaning of the name Ouve

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1782-704: Is the Columbia River , with some mountainous features on the north side of the river, and continues south for approximately 100 miles (160 km) to the Salmon River where Oregon Route 18 crosses the range from the Willamette Valley to the Oregon Coast with width roughly 35 miles (60 km). Located between the Salmon River and the Umpqua River on the north and south, the Central range

1863-532: Is the ninth largest state in the U.S. Oregon's highest point is the summit of Mount Hood, at 11,249 feet (3,429 m), and its lowest point is the sea level of the Pacific Ocean along the Oregon Coast. Oregon's mean elevation is 3,300 feet (1,006 m). Crater Lake National Park , the state's only national park, is the site of the deepest lake in the U.S. at 1,943 feet (592 m). Oregon claims

1944-484: Is the state's highest point. Oregon's only national park, Crater Lake National Park , comprises the caldera surrounding Crater Lake , the deepest lake in the U.S. The state is also home to the single largest organism in the world, Armillaria ostoyae , a fungus that runs beneath 2,200 acres (8.9 km ) of the Malheur National Forest . Oregon's economy has historically been powered by various forms of agriculture, fishing, logging, and hydroelectric power. Oregon

2025-606: Is the third-most populous city in Oregon, with 175,535 residents. Portland , with 652,503, ranks as the 26th among U.S. cities. The Portland metropolitan area , which includes neighboring counties in Washington, is the 25th largest metro area in the nation, with a population of 2,512,859. Oregon is also one of the most geographically diverse states in the U.S., marked by volcanoes, abundant bodies of water, dense evergreen and mixed forests, as well as high deserts and semi-arid shrublands . At 11,249 feet (3,429 m), Mount Hood

2106-605: Is the top lumber producer of the contiguous U.S. , with the lumber industry dominating the state's economy during the 20th century. Technology is another one of Oregon's major economic forces, beginning in the 1970s with the establishment of the Silicon Forest and the expansion of Tektronix and Intel . Sportswear company Nike, Inc. , headquartered in Beaverton , is the state's largest public corporation with an annual revenue of $ 46.7 billion. The origin of

2187-562: The -sint below, so there appeared to be a river flowing to the west named " Ouaricon ". According to the Oregon Tourism Commission , present-day Oregonians / ˌ ɒr ɪ ˈ ɡ oʊ n i ə n z / pronounce the state's name as "or-uh-gun, never or-ee-gone". After being drafted by the Detroit Lions in 2002, former Oregon Ducks quarterback Joey Harrington distributed "Orygun" stickers to members of

2268-789: The Columbia Plateau , the High Desert , and the Blue Mountains . Oregon lies in two time zones . Most of Malheur County is in the Mountain Time Zone , while the rest of the state lies in the Pacific Time Zone . Western Oregon's mountainous regions, home to three of the most prominent mountain peaks of the U.S. including Mount Hood, were formed by the volcanic activity of the Juan de Fuca Plate ,

2349-682: The Coquille River ’s middle fork provides the general dividing line between the Central Range and the Klamath Mountains to the south and east. Birds living in the Southern Coast Range include a variety of smaller and larger bird species. Species include peregrine falcons , pileated woodpeckers , olive-sided flycatcher, and western bluebirds among others. The threatened northern spotted owl also inhabit

2430-578: The Cretaceous Period created offshore islands beginning in the southern portion of the current range. These Roseburg volcanics were followed by the Siletz River Volcanics in the northern portions of the range, and lastly a series of basalt flows from the Columbia River basalts also added to these formations with some smaller flows in-between. Much of the formations are the result of pillow basalt formations created when

2511-648: The D River as the shortest river in the world, though the state of Montana makes the same claim of its Roe River . Oregon is also home to Mill Ends Park (in Portland), the smallest park in the world at 452 square inches (0.29 m ). Oregon is split into eight geographical regions. In Western Oregon : Oregon Coast (west of the Coast Range ), the Willamette Valley, Rogue Valley , Cascade Range and Klamath Mountains ; and in Central and Eastern Oregon :

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2592-934: The Kingdom of Great Britain . The term referred to the then-mythical River of the West (the Columbia River). By 1778, the spelling had shifted to Oregon . Rogers wrote: ...   from the Great Lakes towards the Head of the Mississippi, and from thence to the River called by the Indians Ouragon   ... One suggestion is that this name comes from the French word ouragan ("windstorm" or "hurricane"), which

2673-597: The Lewis and Clark and Astor Expeditions. Few stayed permanently such as Étienne Lussier, often referred to as the first "European" farmer in the state of Oregon. Evidence of the French Canadian presence can be found in numerous names of French origin such as Malheur Lake , the Malheur , Grande Ronde , and Deschutes Rivers , and the city of La Grande . Furthermore, many of the early pioneers first came out West with

2754-618: The Magnitogorsk forearc region. There are two models which characterize a forearc basin formation and deformation and are dependent on sediment deposition and subsidence (see figure). The first model represents a forearc basin formed with little to no sediment supply. Conversely, the second model represents a basin with a healthy sediment supply. Basin depth depends on the supply of oceanic plate sediments, continentally derived clastic material and orthogonal convergence rates. The accretionary flux (sediment supply in and out) also determines

2835-703: The North West Company and the Hudson's Bay Company before heading South of the Columbia for better farmland as the fur trade declined. French Prairie by the Willamette River and French Settlement by the Umpqua River are known as early mixed ancestry settlements. The Lewis and Clark Expedition traveled through northern Oregon also in search of the Northwest Passage . They built their winter fort in 1805–1806 at Fort Clatsop , near

2916-596: The Western U.S. , with the Columbia River delineating much of Oregon's northern boundary with Washington , while the Snake River delineates much of its eastern boundary with Idaho . The 42° north parallel delineates the southern boundary with California and Nevada . The western boundary is formed by the Pacific Ocean . Oregon has been home to many indigenous nations for thousands of years. The first European traders, explorers, and settlers began exploring what

2997-432: The forced relocation of the native population to Indian reservations in Oregon . The first Oregon proposition for a railroad in Oregon was made in 1850 by H. M. Knighton, the original owner of the townsite of St. Helens . Knighton asserted that this would fulfill his township's belief that it should be the supreme metropolitan seaport in that area upon the Columbia River, as opposed to Portland. He suggested building

3078-519: The last glacial period and filled the valley with 300 to 400 feet (91 to 122 m) of water. By the 16th century, Oregon was home to many Native American groups, including the Chinook , Coquille (Ko-Kwell), Bannock , Kalapuya , Klamath , Klickitat , Molala , Nez Perce , Shasta , Takelma , Umatilla , and Umpqua . The first Europeans to visit Oregon were Spanish explorers led by Juan Rodríguez Cabrillo , who sighted southern Oregon off

3159-529: The Coast Range is located in the southwest portion of Oregon between the middle fork of the Coquille River in the south and the Umpqua River on the north. Oregon Route 38 is the general divide between the Central and Southern portions of the Coast Range. Approximately 55 miles (90 km) long, the section contains mountains as high as 3,547 feet (1,081 m) for Bone Mountain . On the south

3240-488: The Coast Range to barren desert in the southeast, which still meets the technical definition of a frontier . Oregon's geographical center is further west than any of the other 48 contiguous states (although the westernmost point of the lower 48 states is in Washington). Central Oregon 's geographical features range from high desert and volcanic rock formations resulting from lava beds . The Oregon Badlands Wilderness

3321-597: The Hudson's Bay Company, reversed the Hudson's Bay Company's long-standing policy of discouraging settlement because it interfered with the lucrative fur trade. He directed that some 200 Red River Colony settlers be relocated to HBC farms near Fort Vancouver, (the James Sinclair expedition), in an attempt to hold Columbia District. Starting in 1842–1843, the Oregon Trail brought many new American settlers to

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3402-557: The Oregon Country. Oregon's boundaries were disputed for a time, contributing to tensions between the U.K. and the U.S., but the border was defined peacefully in the 1846 Oregon Treaty . The border between the U.S. and British North America was set at the 49th parallel . The Oregon Territory was officially organized on August 13, 1848. Settlement increased with the Donation Land Claim Act of 1850 and

3483-741: The Pacific Northwest was particularly affected by the 1973 oil crisis , with Oregon suffering a substantial shortage. In 1972, the Oregon Beverage Container Act of 1971, popularly called the Bottle Bill, became the first law of its kind in the United States. The Bottle Bill system in Oregon was created to control litter. In practice, the system promotes recycling, not reusing, and the collected containers are generally destroyed and made into new containers. Ten states currently have similar laws. In 1994, Oregon became

3564-779: The Pacific coast in 1543. Sailing from Central America on the Golden Hind in 1579 in search of the Strait of Anian during his circumnavigation of the Earth , the English explorer and privateer Sir Francis Drake briefly anchored at South Cove, Cape Arago , just south of Coos Bay , before sailing for what is now California. Martín de Aguilar , continuing separately from Sebastián Vizcaíno 's scouting of California, reached as far north as Cape Blanco and possibly to Coos Bay in 1603. Exploration continued routinely in 1774, starting with

3645-407: The West, although the periodic fluctuations in the U.S. building industry have hurt the state's economy on multiple occasions. Portland, in particular, experienced a population boom between 1900 and 1930, tripling in size; the arrival of World War II also provided the northwest region of the state with an industrial boom, where Liberty ships and aircraft carriers were constructed. During the 1970s,

3726-550: The abundance of fur-bearing animals in the area. Also in 1811, New Yorker John Jacob Astor financed the establishment of Fort Astoria at the mouth of the Columbia River as a western outpost to his Pacific Fur Company ; this was the first permanent European settlement in Oregon. In the War of 1812 , the British gained control of all Pacific Fur Company posts. The Treaty of 1818 established joint British and American occupancy of

3807-412: The accretionary wedge and the volcanic arc can accumulate thick deposits of sediment, sometimes referred to as an outer arc trough. Due to collisional stresses as one tectonic plate subducts under another, forearc regions are sources for powerful earthquakes. During subduction , an oceanic plate is thrust below another tectonic plate, which can be oceanic or continental . Water and other volatiles in

3888-427: The associated volcanic arc . Forearc regions are present along convergent margins and eponymously form 'in front of' the volcanic arcs that are characteristic of convergent plate margins. A back-arc region is the companion region behind the volcanic arc. Many forearcs have an accretionary wedge which may form a topographic ridge known as an outer arc ridge that parallels the volcanic arc. A forearc basin between

3969-594: The early 1800s, and the first permanent European settlements in Oregon were established by fur trappers and traders. In 1843, an autonomous government was formed in the Oregon Country , and the Oregon Territory was created in 1848. Oregon became the 33rd state of the U.S. on February 14, 1859. Today, with 4.2 million people over 98,000 square miles (250,000 km ), Oregon is the ninth largest and 27th most populous U.S. state. The capital, Salem ,

4050-503: The east of the mountains, creating a more stable climate and significantly less rain than the coastal region of the state. To the west where the range over-shadows the Oregon Coast , the range causes more precipitation to fall on that side of the mountains, contributing to the numerous rivers that flow to the Pacific Ocean. Marys Peak in the Central Coast Range is the highest peak at 4,097 feet (1,248 m). Logging

4131-473: The expedition of the frigate Santiago by Juan José Pérez Hernández , and the coast of Oregon became a valuable trade route to Asia. In 1778, British captain James Cook also explored the coast. French Canadians , Scots , Métis , and other continental natives (e.g. Iroquois ) trappers arrived in the late 18th and early 19th centuries, soon to be followed by Catholic clergy. Some traveled as members of

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4212-439: The first U.S. state to legalize physician-assisted suicide through the Oregon Death with Dignity Act . A measure to legalize recreational use of marijuana in Oregon was approved on November 4, 2014, making Oregon only the second state at the time to have legalized gay marriage , physician-assisted suicide, and recreational marijuana. Self service gasoline was banned in Oregon from 1951 until August 2023. Although self-serve

4293-399: The forearc. There is evidence from geothermal data and models which show the slab-mantle interface, levels of friction and the cool oceanic lithosphere at the trench. Other examples are: Oregon Oregon ( / ˈ ɒr ɪ ɡ ən , - ɡ ɒ n / ORR -ih-ghən , -⁠gon ) is a state in the Pacific Northwest region of the United States. It is a part of

4374-477: The form of rain , with snow during the winter months at the higher elevations, but no permanent snow pack . Annual precipitation differs from 60 inches (1,500 mm) in some parts to up to 120 inches (3,000 mm), with the higher amounts coming in the higher elevations. The average high temperature in January is 36.3 °F (2.4 °C), and the average high in July is 61.9 °F (16.6 °C) with temperatures also varying by elevation. The further inland and

4455-420: The growth of railroads expanded the state's lumber , wheat , and other agricultural markets, and the rapid growth of its cities. Due to the abundance of timber and waterway access via the Willamette River, Portland became a major force in the lumber industry of the Pacific Northwest , and quickly became the state's largest city. It would earn the nickname "Stumptown", and would later become recognized as one of

4536-418: The layers that were uplifted, as the newer Cascade Mountains had not yet been formed. By the Early Oligocene period c. 30 million years ago the current coastline was in place and erosion has continued to shape the range. primarily through rivers cutting deep valleys through the igneous and sedimentary rocks. The geologic boundaries of the coast range formation extend from southwest Washington state in

4617-433: The lower 48 states. Moose have not always inhabited the state but came to Oregon in the 1960s; the Wallowa Valley herd numbered about 60 as of 2013 . Gray wolves were extirpated from Oregon around 1930 but have since found their way back; most reside in northeast Oregon, with two packs living in the south-central part. Although their existence in Oregon is unconfirmed, reports of grizzly bears still turn up, and it

4698-429: The media as a reminder of how to pronounce the name of his home state. The stickers are sold by the University of Oregon Bookstore . While there is considerable evidence that Paleo-Indians inhabited the region, the oldest evidence of habitation in Oregon was found at Fort Rock Cave and the Paisley Caves in Lake County . Archaeologist Luther Cressman dated material from Fort Rock to 13,200 years ago, and there

4779-468: The more southerly portions have a more Mediterranean climate that is more similar to the climate of the Willamette Valley. The Coast Range creates a rain shadow effect by forcing moisture laden clouds to rise by expelling moisture. This shields the Willamette Valley and causes a less maritime climate with hotter summers and less precipitation than the Oregon Coast. The Oregon Coast Range is divided into three separate sections: North, Central, and South. In

4860-415: The most dangerous port cities in the United States due to racketeering and illegal activities at the turn of the 20th century. In 1902, Oregon introduced direct legislation by the state's citizens through initiatives and referendums , known as the Oregon System . On May 5, 1945, six civilians were killed by a Japanese balloon bomb that exploded on Gearhart Mountain near Bly . They remained

4941-427: The mountain forests. Animal life in the rivers, streams, and lakes include lamprey , coastal cutthroat trout , dace , Umpqua chub, frogs, salamander, turtles, coho salmon , steelhead trout , and others. Five tallest peaks in the Oregon Coast Range: The following rivers have their headwaters in the Oregon Coast Range: Forearc A forearc is a region in a subduction zone between an oceanic trench and

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5022-489: The mountains. Located in the northwest portion of Oregon this section of the range has peaks as high as 3,706 feet (1,130 m) for Rogers Peak . Forests here are considered to be some of the most productive timber land in the world. Trees include primarily Sitka spruce , western redcedar , Douglas-fir , and western hemlock . Other plants include huckleberry, salmonberry, salal, vine maple, Oregon grape , bracken fern, and thimble-berry among others. The northern boundary

5103-466: The mouth of the Columbia River, staying at the encampment from December until March. British explorer David Thompson also conducted overland exploration. In 1811, while working for the North West Company, Thompson became the first European to navigate the entire Columbia River. Stopping on the way, at the junction of the Snake River, he posted a claim to the region for Great Britain and the North West Company. Upon returning to Montreal , he publicized

5184-418: The north to around the Coquille River in the south where the older and taller Klamath Mountains begin. In the east the mountains begin as foothills forming the western edge of the Willamette Valley and continue west to the coastline and beyond where the basalt formation tapers off into the continental shelf and ends at the continental slope with several banks and basins off shore. Physiographically, they are

5265-400: The only people on American soil whose deaths were attributed to an enemy balloon bomb explosion during World War II . The bombing site is now located in the Mitchell Recreation Area . Industrial expansion began in earnest following the 1933–1937 construction of the Bonneville Dam on the Columbia River. Hydroelectric power , food, and lumber provided by Oregon helped fuel the development of

5346-404: The overriding and underthrusting plates in the forearc regions have shown to evolve strong coupling mechanisms which result in megathrust earthquakes such as the Tohoku-oki earthquake which occurred off the Pacific coast of Northeast Japan (Tian and Liu. 2013). These mega thrust earthquakes may be correlated with low values of heat flow generally associated with forearc regions. Geothermal data shows

5427-411: The overriding plate and the subducting slab experiences corner flow near the back-arc driven by the down dip motion of the subducting slab. At the same time, the temperature of the mantle wedge closer to the trench is dominated by the denser and colder subducting slab, resulting in a cold, stagnant portion of the mantle wedge. Initial theories proposed that the oceanic trenches and magmatic arcs were

5508-466: The primary suppliers of the accretionary sedimentation wedges in the forearc regions. More recent discovery suggests that some of the accreted material in the forearc region is from a mantle source along with trench turbidites derived from continental material. This theory holds due to evidence of pelagic sediments and continental crust being subducted in processes known as sediment subduction and subduction erosion respectively. Over geological time there

5589-411: The prisms) compared to the younger deposits (basins). Forearc regions are also where ophiolites are emplaced should obduction occur, but such deposits are not continuous and can often be removed by erosion. As tectonic plates converge, the closing of an ocean will result in the convergence of two landmasses, each of which is either an island arc or continental margin. When these two bodies collide,

5670-404: The rate at which the sedimentation wedges grow within the forearc. The age of the oceanic crust along with the convergent velocity controls the coupling across the converging interface of the continental and oceanic crust. The strength of this coupling controls the deformation associated with the event and can be seen in the forearc region deformation signatures. The intense interaction between

5751-410: The region after the law was passed were forced to leave, and those who did not comply were arrested and beaten. They received no less than twenty and no more than thirty-nine stripes across the back if they still did not leave. This process could be repeated every six months. Slavery played a major part in Oregon's history and even influenced its path to statehood. The territory's request for statehood

5832-584: The region west of the Rocky Mountains to the Pacific Ocean. By the 1820s and 1830s, the Hudson's Bay Company dominated the Pacific Northwest from its Columbia District headquarters at Fort Vancouver (built in 1825 by the district's chief factor, John McLoughlin , across the Columbia from present-day Portland ). In 1841, the expert trapper and entrepreneur Ewing Young died leaving considerable wealth and no apparent heir, and no system to probate his estate. A meeting followed Young's funeral, at which

5913-402: The result is orogenesis , at which time the underthrusting oceanic crust slows down. In early stages of arc-continent collision, there is uplift and erosion of the accretionary prism and forearc basin. In the later stages of collision, the forearc region may be sutured, rotated and shortened which can form syn-collisional folds and thrust belts. At the surface, the forearc region can include

5994-760: The south is the oldest portion of the range with formation beginning in the Paleocene era with the Roseburg volcanics, while the newest section is the northernmost portion formed first with the Siletz River Volcanics. The Central and Northern sections contain more sedimentary rocks from the mud, silt, sand, and other volcanic debris than the lower Southern section. Also, the Oregon Coast Range is home to over 50 mammal species, over 100 species of birds, and nearly 30 reptile or amphibian species that spent significant portions of their life cycle in

6075-421: The state's name is uncertain. The earliest geographical designation "orejón" (meaning "big ear") comes from the Spanish historical chronicle Relación de la Alta y Baja California (1598), written by Rodrigo Montezuma of New Spain ; here it refers to the region of the Columbia River as it was encountered by the first Spanish scouts. The " j " in the Spanish phrase " El Orejón " was eventually corrupted into

6156-433: The subducting plate cause flux melting in the upper mantle , creating magma that rises and penetrates the overriding plate, forming a volcanic arc . The weight of the subducting slab flexes the overriding plate and creates an oceanic trench . This area between the trench and the arc is called the forearc region, with the area behind the arc and away from the trench known as the back-arc region . The mantle region between

6237-481: The tectonic forcing which causes the oceanic lithosphere to descend. The relationship between surface slope and subduction thrust also plays a huge role in the variation of forearc structure and deformation. A subduction wedge can be classified as either stable with little deformation or unstable with pervasive internal deformation (see section on Models). Some common deformation in forearc sediments are synsedimentary deformation and olistostromes , such as that seen in

6318-413: The volcanic arc and substrate can accumulate into a forearc basin which overlays the oldest thrust slices in the wedge of the forearc region. In general, the forearc topography (specifically in the trench region) is trying to achieve an equilibrium between buoyancy and tectonic forces caused by subduction. Upward motion of the forearc is related to buoyancy forces and the downward motion is associated with

6399-724: Was applied to the River of the West based on Native American tales of powerful Chinook winds on the lower Columbia River, or perhaps from first-hand French experience with the Chinook winds of the Great Plains . At the time, the River of the West was thought to rise in western Minnesota and flow west through the Great Plains. Another suggestion comes from Joaquin Miller , who wrote in Sunset magazine in 1904: The name, Oregon,

6480-574: Was delayed several times, as members of Congress argued among themselves whether the territory should be admitted as a "free" or "slave" state. Eventually politicians from the South agreed to allow Oregon to enter as a "free" state, in exchange for opening slavery to the Southwestern U.S. Oregon was admitted to the Union on February 14, 1859, though no one in Oregon knew it until March 15. Founded as

6561-438: Was the first acting public government of the Oregon Country before annexation by the government of the United States. It was succeeded by a Second Executive Committee, made up of Peter G. Stewart , Osborne Russell , and William J. Bailey , and this committee was itself succeeded by George Abernethy , who was the first and only Governor of Oregon under the provisional government. Also in 1841, Sir George Simpson , governor of

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