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Larch Mountain (Multnomah County, Oregon)
Larch Mountain is an extinct volcano near Portland, Oregon, Portland, Oregon. The name is misleading, as no western larch (a large coniferous tree) can be found there. It received that name when early lumbermen sold the noble fir wood as larch. The peak can be reached between May and November on paved Larch Mountain Road, east of Corbett, Oregon, although the road is closed during the winter and spring months. The road leading to Larch Mountain from the Historic Columbia River Highway is 14 miles long, which closed at milepost 10 from Nov. through late May or early June due to snow. Geography Larch Mountain is located in Multnomah County, Oregon approximately east of Portland, Oregon, Portland, above the Columbia River Gorge. Although it has an elevation of , its prominence above the surrounding terrain is only . The summit of the mountain is accessible by Larch Mountain Road between May and November, which branches off from the Historic Columbia River Highway east of Corbett, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washougal, Washington
Washougal ( ) is a city in Clark County, Washington, United States. The population was 17,039 as of the 2020 census. History Washougal was officially incorporated on December 4, 1908. Its Mount Pleasant Grange Hall is the oldest continually used grange hall in Washington. This small community is located on the Washington side of the Columbia River, with its lowlands and famous prairie situated on the west entrance to the scenic Columbia River Gorge. Motorists who approach Washougal from the west on the Lewis & Clark Highway can see Mount Hood rising above the Cascade Mountains framed by the columnar cliffs that signal the gateway of the Gorge. It is home to Excelsior High School and Washougal High School. It can be accurately stated that Washougal is the "crossroads to discovery" in the Pacific Northwest. Shortly after Capt. Robert Gray, a Boston fur trader, entered the mouth of the Columbia River in May 1792, the famed British explorer George Vancouver traveled to the reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Oregonian
''The Oregonian'' is a daily newspaper based in Portland, Oregon, United States, owned by Advance Publications. It is the oldest continuously published newspaper on the U.S. west coast, founded as a weekly by Thomas J. Dryer on December 4, 1850, and published daily since 1861. It is the largest newspaper in Oregon and the second largest in the Pacific Northwest by circulation. It is one of the few newspapers with a statewide focus in the United States. The Sunday edition is published under the title ''The Sunday Oregonian''. The regular edition was published under the title ''The Morning Oregonian'' from 1861 until 1937. ''The Oregonian'' received the 2001 Pulitzer Prize for Public Service, the only gold medal annually awarded by the organization. The paper's staff or individual writers have received seven other Pulitzer Prizes, most recently the award for Editorial Writing in 2014. ''The Oregonian'' is home-delivered throughout Multnomah, Washington, Clackamas, and Yamhill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Plug
A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising volatile-charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption. In a plinian eruption the plug is destroyed and ash is ejected. Glacial erosion can lead to exposure of the plug on one side, while a long slope of material remains on the opposite side. Such landforms are called crag and tail. If a plug is preserved, erosion may remove the surrounding rock while the erosion-resistant plug remains, producing a distinctive upstanding landform. Examples of volcanic plugs Africa Near the village of Rhumsiki in the Far North Province of Cameroon, Kapsiki Peak is an example of a volcanic plug and is one of the most photographed parts of the Mandara Mountains. Spectacular volcanic plugs are present in the center of La Gomer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brittle
A material is brittle if, when subjected to stress, it fractures with little elastic deformation and without significant plastic deformation. Brittle materials absorb relatively little energy prior to fracture, even those of high strength. Breaking is often accompanied by a sharp snapping sound. When used in materials science, it is generally applied to materials that fail when there is little or no plastic deformation before failure. One proof is to match the broken halves, which should fit exactly since no plastic deformation has occurred. Brittleness in different materials Polymers Mechanical characteristics of polymers can be sensitive to temperature changes near room temperatures. For example, poly(methyl methacrylate) is extremely brittle at temperature 4˚C, but experiences increased ductility with increased temperature. Amorphous polymers are polymers that can behave differently at different temperatures. They may behave like a glass at low temperatures (the glassy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia River Basalt
The Columbia River Basalt Group is the youngest, smallest and one of the best-preserved continental flood basalt province on Earth, covering over mainly eastern Oregon and Washington, western Idaho, and part of northern Nevada. The basalt group includes the Steens and Picture Gorge basalt formations. Introduction During the middle to late Miocene epoch, the Columbia River flood basalts engulfed about of the Pacific Northwest, forming a large igneous province with an estimated volume of . Eruptions were most vigorous 17–14 million years ago, when over 99 percent of the basalt was released. Less extensive eruptions continued 14–6 million years ago. Erosion resulting from the Missoula Floods has extensively exposed these lava flows, laying bare many layers of the basalt flows at Wallula Gap, the lower Palouse River, the Columbia River Gorge and throughout the Channeled Scablands. The Columbia River Basalt Group is thought to be a potential link to the Chilc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andesite
Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende. Andesite is the extrusive equivalent of plutonic diorite. Characteristic of subduction zones, andesite represents the dominant rock type in island arcs. The average composition of the continental crust is andesitic. Along with basalts, andesites are a component of the Martian crust. The name ''andesite'' is derived from the Andes mountain range, where this rock type is found in abundance. It was first applied by Christian Leopold von Buch in 1826. Description Andesite is an aphanitic (fine-grained) igneous rock that is intermediate in its content of silica and low in alkali metals. It has less than 20% quartz and 10% feldspathoid by volume, with at least 65% of the fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial planet, rocky planet or natural satellite, moon. More than 90% of all volcanic rock on Earth is basalt. Rapid-cooling, fine-grained basalt is chemically equivalent to slow-cooling, coarse-grained gabbro. The eruption of basalt lava is observed by geologists at about 20 volcanoes per year. Basalt is also an important rock type on other planetary bodies in the Solar System. For example, the bulk of the plains of volcanism on Venus, Venus, which cover ~80% of the surface, are basaltic; the lunar mare, lunar maria are plains of flood-basaltic lava flows; and basalt is a common rock on the surface of Mars. Molten basalt lava has a low viscosity due to its relatively low silica content (between 45% and 52%), resulting in rapidly moving lava flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plio-Pleistocene
The Plio-Pleistocene is an informally described geological pseudo-period, which begins about 5 million years ago (Mya) and, drawing forward, combines the time ranges of the formally defined Pliocene and Pleistocene epochs—marking from about 5 Mya to about 12 kya. Nominally, the Holocene epoch—the last 12 thousand years—would be excluded, but most Earth scientists would probably treat the current times as incorporated into the term "Plio-Pleistocene"; see below. In the contexts of archaeology, paleontology, and paleoanthropology, the Plio-Pleistocene is a very useful period to which scientists may assign the long and continuous run in East Africa of datable sedimentary layers and their contents (e.g. the Bouri Formation). These contents collectively present a focused view of the continuous evolution of the region's large vertebrates, especially the evolution of some African apes (hominids) to the earliest hominins; and then the development of the early humans and thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Field
A volcanic field is an area of Earth's crust that is prone to localized volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. Volcanic fields usually consist of clusters of up to 100 volcanoes such as cinder cones. Lava flows may also occur. They may occur as a monogenetic volcanic field or a polygenetic volcanic field. Description Alexander von Humboldt observed in 1823 that geologically young volcanoes are not distributed uniformly across the Earth's surface, but tend to be clustered into specific regions. Young volcanoes are rarely found within cratons, but are characteristic of subduction zones, rift zones, or in ocean basins. Intraplate volcanoes are clustered along hotspot traces. Within regions of volcanic activity, volcanic fields are clusters of volcanoes that share a common magma source. Scoria cones are particularly prone to cluster into volcanic fields, which are typically in diameter and consist of several tens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shield Volcano
A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava erupted from a stratovolcano. Repeated eruptions result in the steady accumulation of broad sheets of lava, building up the shield volcano's distinctive form. Shield volcanoes are found wherever fluid low-silica lava reaches the surface of a rocky planet. However, they are most characteristic of ocean island volcanism associated with hot spots or with continental rift volcanism. They include the largest volcanoes on earth, such as Tamu Massif and Mauna Loa. Giant shield volcanoes are found on other planets of the Solar System, including Olympus Mons on Mars and Sapas Mons on Venus. Etymology The term 'shield volcano' is taken from the German term ''Schildvulkan'', coined by the Austrian geologist Eduard Suess in 1888 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridal Veil, Oregon
Bridal Veil is a virtual ghost town located in Multnomah County, Oregon, United States. It was established in the 1880s during a logging boom by a logging company as it harvested timber on nearby Larch Mountain to be a company mill town around a sawmill. It had a close relationship with the logging town of Palmer for the first 50 years of its history. As of November 2011, all that remains of the town is a post office and a cemetery. The site is located near the west end of the Columbia River Gorge. History Bridal Veil was established in 1886. Bridal Veil functioned as the Bridal Veil Falls Lumbering Company and built a sawmill one mile (1.6 km) up Larch Mountain. The company operated in Bridal Veil and the surrounding area from 1886 to 1936. A mile and half up the timber-rich mountain was the logging town of Palmer. Palmer and Bridal Veil shared common ownership as company mill towns. Together, the two towns produced lumber and were codependent. A V-shaped log flume was b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
