|
Zigzag Mountain
Zigzag Mountain is a volcanic mountain in Clackamas County in the U.S. state of Oregon. It is located west-southwest of Mount Hood, northwest of Government Camp, east of Zigzag, and north of the Zigzag River. Because of its proximity to Mount Hood, it is considered a foothill. The highest peak has an elevation of over . Another peak, East Zigzag, is and was the site of a United States Forest Service fire lookout station which was destroyed prior to 1970. The mountain is capped by Pliocene andesite and basalt. The "Zigzag" name used was apparently derived from Oregon pioneer Joel Palmer's description of the zigzagging route he used to descend from Mount Hood's Zigzag Canyon (in which Zigzag Glacier Zigzag Glacier is an alpine glacier located on the upper southwest slopes of Mount Hood in the U.S. state of Oregon. It ranges in elevation from with fingers in canyons extending to about , and lies almost entirely within Mount Hood Wilderness. ... is located) and on down what ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Hood
Mount Hood is a potentially active stratovolcano in the Cascade Volcanic Arc. It was formed by a subduction zone on the Pacific coast and rests in the Pacific Northwest region of the United States. It is located about east-southeast of Portland, on the border between Clackamas and Hood River counties. In addition to being Oregon's highest mountain, it is one of the loftiest mountains in the nation based on its prominence, and it offers the only year-round lift-served skiing in North America. The height assigned to Mount Hood's snow-covered peak has varied over its history. Modern sources point to three different heights: , a 1991 adjustment of a 1986 measurement by the U.S. National Geodetic Survey (NGS), based on a 1993 scientific expedition, and of slightly older origin. The peak is home to 12 named glaciers and snowfields. It is the highest point in Oregon and the fourth highest in the Cascade Range. Mount Hood is considered the Oregon volcano most likely to erupt, thoug ... [...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] |
Mountains Of Clackamas County, Oregon
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least 300 metres (1,000 feet) above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges. Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. High elevations on mountains produce colder climates than at sea level at similar latitude. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of Clackamas County, Oregon
A volcano is a rupture in the Crust (geology), crust of a Planet#Planetary-mass objects, planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where list of tectonic plates, tectonic plates are divergent boundary, diverging or convergent boundary, converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountains Of Oregon
This article comprises three sortable tables of major mountain peaksThis article defines a significant summit as a summit with at least of topographic prominence, and a major summit as a summit with at least of topographic prominence. All summits in this article have at least 500 meters of topographic prominence. An ultra-prominent summit is a summit with at least of topographic prominence. of the U.S. State of Oregon. The summit of a mountain or hill may be measured in three principal ways: #The topographic elevation of a summit measures the height of the summit above a geodetic sea level.All elevations in this article include an elevation adjustment from the National Geodetic Vertical Datum of 1929 (NGVD 29) to the North American Vertical Datum of 1988 (NAVD 88). For further information, please see this United States National Geodetic Surveybr>noteIf the elevation or prominence of a summit is calculated as a range of values, the arithmetic mean is shown. The fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USGS
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredth anniv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portland, Oregon
Portland (, ) is a port city in the Pacific Northwest and the largest city in the U.S. state of Oregon. Situated at the confluence of the Willamette and Columbia rivers, Portland is the county seat of Multnomah County, the most populous county in Oregon. Portland had a population of 652,503, making it the 26th-most populated city in the United States, the sixth-most populous on the West Coast, and the second-most populous in the Pacific Northwest, after Seattle. Approximately 2.5 million people live in the Portland metropolitan statistical area (MSA), making it the 25th most populous in the United States. About half of Oregon's population resides within the Portland metropolitan area. Named after Portland, Maine, the Oregon settlement began to be populated in the 1840s, near the end of the Oregon Trail. Its water access provided convenient transportation of goods, and the timber industry was a major force in the city's early economy. At the turn of the 20th century, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oregon Historical Society
The Oregon Historical Society (OHS) is an organization that encourages and promotes the study and understanding of the history of the Oregon Country, within the broader context of U.S. history. Incorporated in 1898, the Society collects, preserves, and makes available materials of historical character and interest, and collaborates with other groups and individuals with similar aims. The society operates the Oregon History Center that includes the Oregon Historical Society Museum in downtown Portland. History The Society was organized on December 17, 1898, in Portland at the Portland Library Building.Corning, Howard M. ''Dictionary of Oregon History''. Binfords & Mort Publishing, 1956. Its mission, as expressed in the first volume of its ''Oregon Historical Quarterly'', was to "bring together in the most complete measure possible the data for the history of the commonwealth, and to stimulate the widest and highest use of them." The first president was Harvey W. Scott, with memb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zigzag Glacier
Zigzag Glacier is an alpine glacier located on the upper southwest slopes of Mount Hood in the U.S. state of Oregon. It ranges in elevation from with fingers in canyons extending to about , and lies almost entirely within Mount Hood Wilderness. The upper extent is divided from Reid Glacier by Illumination Rock. The top of the glacier is at the foot of Crater Rock. The glacier is bounded on the east by a slight rise shared with the Palmer Glacier (a popular skiing area north of Timberline Lodge since the 1930s) and on the northwest by Reid Glacier. It is the source of the Zigzag River which has eroded a large, steep canyon named Zigzag Canyon. Below the glacier, its snowfield varies significantly seasonally, varying in length by almost two miles (3.2 km). In 1922, a jökulhlaup originating from Zigzag Glacier as a flow of dark debris came out of a crevasse high on the glacier. It flowed on the surface more than 650 m (2100 ft) before entering another crevasse, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joel Palmer
General Joel Palmer (October 4, 1810 – June 9, 1881) was an American pioneer of the Oregon Territory in the Pacific Northwest region of North America. He was born in Canada, and spent his early years in New York and Pennsylvania before serving as a member of the Indiana House of Representatives. Palmer traveled to the Oregon Country in 1845. He played a central role in blazing the last leg of the Oregon Trail, the Barlow Road, with Sam Barlow and others. Specifically, Palmer is noted for having climbed high on Mount Hood to observe the surrounding area when the party ran into difficulty. He wrote a popular immigrant guidebook, co-founded Dayton, Oregon, and served as a controversial Indian Affairs administrator. After Oregon became a state, Palmer served in both branches of the Oregon Legislative Assembly. He was selected as Speaker of the Oregon House of Representatives for one session in 1862, and in 1870 lost a bid to become Governor of Oregon. The Palmer House, his former ... [...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] |
Cascades Range
The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades. The small part of the range in British Columbia is referred to as the Canadian Cascades or, locally, as the Cascade Mountains. The latter term is also sometimes used by Washington residents to refer to the Washington section of the Cascades in addition to North Cascades, the more usual U.S. term, as in North Cascades National Park. The highest peak in the range is Mount Rainier in Washington at . part of the Pacific Ocean's Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean. All of the eruptions in the contiguous United States over the last 200 years have been from Cascade volcanoes. The two most recent were Lassen Peak from 1914 to 1921 and a major e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
