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Blue Mountains (Pacific Northwest)
The Blue Mountains are a mountain range in the northwestern United States, located largely in northeastern Oregon and stretching into extreme southeastern Washington. The range has an area of about , stretching east and southeast of Pendleton, Oregon, to the Snake River along the Oregon–Idaho border. The Blue Mountains cover ten counties across two states; they are Union, Umatilla, Grant, Baker, Wallowa and Harney counties in Oregon, and Walla Walla, Columbia, Garfield and Asotin counties in Washington. The mountains are unique as the home of the world's largest living organism, a subterranean colonial mycelial mat of the fungus ''Armillaria ostoyae''. The Blue Mountains were named after the color of the mountains when seen from a distance. Geology The Blues are uplift mountainscbgwma.orThe Columbia River Basalt Group , Continental flood basalt flows , cbgwma.org accessdate: February 8, 2017 and contain some of the oldest rocks in Oregon. Rocks as old as 400 million yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baker City, Oregon
Baker City is a city in and the county seat of Baker County, Oregon, United States. It was named after Edward D. Baker, the only U.S. Senator ever killed in military combat. The population was 10,099 at the time of the 2020 census. History Platted in 1865, Baker City grew slowly in the beginning. A post office was established on March 27, 1866, but Baker City was not incorporated until 1874. Even so, it supplanted Auburn as the county seat in 1868. The city and county were named in honor of U.S. Senator Edward D. Baker, the only sitting senator to be killed in a military engagement. He died in 1861 while leading a charge of 1,700 Union Army soldiers up a ridge at Ball's Bluff, Virginia, during the American Civil War. The Oregon Short Line Railroad came to Baker City in 1884, prompting growth; by 1900 it was the largest city between Salt Lake City and Portland and a trading center for a broad region. In 1910, Baker City residents voted to shorten the name of the city to simpl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garfield County, Washington
Garfield County is a county located in the U.S. state of Washington. As of the 2020 census, the population was 2,286, making it the least populous county in Washington; with about , it is also the least densely populated county in Washington. The county seat and only city is Pomeroy. History The area delineated by the future Washington state boundary began to be colonized at the start of the nineteenth century, both by Americans and British. However, the majority of British exploration and interest in the land was due to the fur trade, whereas American settlers were principally seeking land for agriculture and cattle raising. The Treaty of 1818 provided for the creation of a British and American condominium over the region. During this period, the future Washington Territory was divided into two administrative zones: Clark County and Lewis County (made official in 1845). However, the condominium arrangement was unwieldy, leading to continuous disputes and occasional conflict; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldrich Mountains
The Aldrich Mountains are a mountain range in Grant County, Oregon, Grant County, Oregon, United States. An east–west range rising south of the John Day River valley, the mountains are bounded on the west by the South Fork John Day River, on the south by Murderers Creek and the Bear Valley, and on the east by Canyon Creek. Most of the Aldrich Mountains and the mountainous terrain south of them are contained within the Malheur National Forest. The highest point in the range is Fields Peak at , and the nearest human settlement is Mount Vernon, Oregon, Mount Vernon, located in the John Day River valley. Across the South Fork John Day River to the west are the Ochoco Mountains, while across Canyon Creek to the east is the Strawberry Range. References External links *Cedar Grove Botanical Area - Conifer Country blog Malheur National Forest Mountain ranges of Oregon Mountain ranges of Grant County, Oregon {{GrantCountyOR-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenhorn Mountains (Oregon)
The Greenhorn Mountains are a small mountain range in Grant and Baker counties in the U.S. state of Oregon. They are part of the Blue Mountains. See also *Greenhorn, Oregon Greenhorn is a non-populated city in Baker and Grant counties in the U.S. state of Oregon. It straddles the Blue Mountain ridge, so that it is located in both Grant County and Baker County. As most of the city is situated in Baker County, and the ... References Mountain ranges of Oregon Mountain ranges of Baker County, Oregon Mountain ranges of Grant County, Oregon {{GrantCountyOR-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prineville, Oregon
Prineville is a city in and the seat of Crook County, Oregon, United States. It was named for the first merchant located in the present location, Barney Prine. The population was 9,253 at the 2010 census. History Prineville was founded in 1877 when Monroe Hodges filed the original plat for the city. The post office for the community had been established with the name of Prine on April 13, 1871, but changed to Prineville on December 23, 1872. The city was incorporated by the Oregon Legislative Assembly on October 23, 1880, and obtained its first high school in 1902. Long the major town in central Oregon, Prineville was snubbed in 1911 when the railroad tycoons James J. Hill and Edward H. Harriman bypassed the city as they laid track south from The Dalles. In a period when the presence of a railroad meant the difference between prosperity and the eventual fate as a ghost town, in a 1917 election, Prineville residents voted 355 to 1 to build their own railway, and raised the mon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maury Mountains
The Maury Mountains are a mountain range in Crook County, Oregon. Much of the range is within the Ochoco National Forest. Outstanding features of the range are the Maury Mountains Agate Beds and Antelope Flat Reservoir Antelope Flat Reservoir is an impoundment located in the southern part of the Maury Mountains in Crook County, Oregon. It is formed by a high earth-fill dam built across Bear Creek for irrigation purposes. The western part of the lake is within .... References Mountains of Crook County, Oregon Mountain ranges of Oregon Ochoco National Forest {{CrookCountyOR-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ochoco Mountains
The Ochoco Mountains are a mountain range in central Oregon in the United States, located at the western end of the Blue Mountains. They were formed when Permian, Triassic, and Jurassic rocks were slowly uplifted by volcanic eruptions to form the Clarno Formation. Today, the highest point in the range is Lookout Mountain. The dominant vegetation on the west side of the range is old-growth ponderosa pine; on the east side, western juniper is common. The western area of the mountains is administered by the Ochoco National Forest, while the southeastern section is part of the Malheur National Forest. The Ochoco Mountains are used for hiking, camping, bird watching, rockhounding, and hunting, as well as cross-country skiing in the winter. Geography The Ochoco Mountains run north to south and east to west. The eight highest peaks in the range are: * Lookout Mountain, * Spanish Peak, * Mount Pisgah, * Round Mountain, * East Point, * North Point, * Wolf Mountain, * View ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Intrusion
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and compositions, illustrated by examples like the Palisades Sill of New York and New Jersey; the Henry Mountains of Utah; the Bushveld Igneous Complex of South Africa; Shiprock in New Mexico; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California. Because the solid country rock into which magma intrudes is an excellent insulator, cooling of the magma is extremely slow, and intrusive igneous rock is coarse-grained (phaneritic). Intrusive igneous rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz, alkali feldspar, plagioclase, and feldspathoid is particularly important in classifying intrusive igneous rocks. Intrusions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Plate
The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacific Plate (which borders the plate to the west). It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust. The interior of the main continental landmass includes an extensive granitic core called a craton. Along most of the edges of this craton are fragments of crustal material called terranes, which are accreted to the craton by tectonic actions over a long span of time. It is thought that much of North America west of the Rocky Mountains is composed of such terranes. Boundaries The southern boundary with the Cocos Plate to the west and the Caribbean Plate to the east is a transform fault, represented by the Swan Islands Transform Fault unde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accretion (geology)
Accretion, in geology, is a process by which material is added to a tectonic plate at a subduction zone, frequently on the edge of existing continental landmasses. The added material may be sediment, volcanic arcs, seamounts, oceanic crust or other igneous features. Description Accretion involves the addition of material to a tectonic plate via subduction, the process by which one plate is forced under the other when two plates collide. The plate which is being forced down, the subducted plate, is pushed against the upper, over-riding plate. Sediment on the ocean floor of the subducting plate is often scraped off as the plate descends. This accumulated material is called an accretionary wedge (or accretionary prism), which is pushed against and attaches to the upper plate. In addition to accumulated ocean sediments, volcanic island arcs or seamounts present on the subducting plate may be amalgamated onto existing continental crust on the upper plate, increasing the continental ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Island Arc
Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle along the subduction, subduction zone. They are the principal way by which continental growth is achieved. Island arcs can either be active or inactive based on their seismicity and presence of volcanoes. Active arcs are ridges of recent volcanoes with an associated deep seismic zone. They also possess a distinct curved form, a chain of active or recently extinct volcanoes, a Oceanic trench, deep-sea trench, and a large negative Bouguer anomaly on the convex side of the volcanic arc. The small positive gravity anomaly associated with volcanic arcs has been interpreted by many authors as due to the presence of dense volcanic rocks beneath the arc. Inactive arcs are a chain of islands which contains older volcanic and volcaniclastic rocks. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
