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Penis Pump juice...mmmmmmmmmmm Image File history File links Medicine_Lake_Volcano_from_Captain_Jack's_Stronghold_in_Lava_Beds_NM-750px. ...
Lava Beds National Monument, located in Siskiyou and Modoc Counies, California, is the site of the largest concentration of lava tube caves in the United States. ...
A topographical summit is a point on a surface which is higher in elevation than all points immediately adjacent to it. ...
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A mountain range is a group of mountains bordered by lowlands or separated from other mountain ranges by passes or rivers. ...
Mount Adams in Washington The Cascade Range is a mountainous region famous for its chain of tall volcanoes called the High Cascades that run north-south along the west coast of North America from British Columbia through Washington and Oregon to the Shasta Cascade area of northern California. ...
Map of Earth showing lines of latitude (horizontally) and longitude (vertically), Eckert VI projection; large version (pdf, 1. ...
Mountains can be characterized in several ways. ...
Shield volcano Mauna Kea, a shield volcano, on the Island of Hawai‘i with a light dusting of snow. ...
Volcano 1. ...
Medicine Lake Volcano is a large shield volcano in the northeastern California about 50 kilometres (30 miles) northeast of Mount Shasta. The volcano is located in a zone of east-west crustal extension east of the main axis of the Cascade Range. The 1-km-thick shield is 35 km (22 miles) from east to west and 45 to 50 km (72 to 30 miles) from north to south, and covers more than 2000 km² (770 mi²). The volcano is primarily composed of basalt and basaltic andesite lava flows, and has a 7 by 12 km (4.3 by 7.4 mile) caldera at the center. Shield volcano Mauna Kea, a shield volcano, on the Island of Hawai‘i with a light dusting of snow. ...
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Mount Shasta, a 14,162-foot (4,322 m) stratovolcano, is the second-highest peak in the Cascade Range and the seventh-highest peak in California. ...
Volcano 1. ...
Mount Adams in Washington The Cascade Range is a mountainous region famous for its chain of tall volcanoes called the High Cascades that run north-south along the west coast of North America from British Columbia through Washington and Oregon to the Shasta Cascade area of northern California. ...
Basalt Basalt is a common gray to black volcanic rock. ...
A sample of andesite (dark groundmass) with amygdaloidal vesicules filled with zeolite. ...
Satellite image of Santorini. ...
The Medicine Lake shield rises about 1200 metres (4000 feet) above the Modoc Plateau to an elevation of 2,376 metres (7795 feet). Lavas from Medicine Lake Volcano are estimated to be at least 600 cubic km in volume, making Medicine Lake the largest volcano by volume in the Cascade Range (nearby Mount Shasta has the second highest volume). Lava Beds National Monument lies on the northeast flank of the volcano. The Modoc Plateau lies in the northeast corner of California as well as parts of Oregon and Nevada. ...
Look up lava, Aa, pahoehoe in Wiktionary, the free dictionary. ...
Volume, also called capacity, is a quantification of how much space an object occupies. ...
Lava Beds National Monument, located in Siskiyou and Modoc Counies, California, is the site of the largest concentration of lava tube caves in the United States. ...
Filling up the entire southern skyline, it has been erupting off and on for half a million years. The eruptions were gentle rather than explosive like Mount St. Helens, coating the volcano's sides with flow after flow of basaltic lava. Medicine Lake is part of the old caldera, a bowl-shaped depression in the mountain. It is believed that the Medicine Lake volcano is unique, having many small magma chambers rather than one large one. Mount St. ...
The Caldera Medicine Lake caldera is a 7 by 12 km depression (4.3 by 7.4 mile) in the summit area of the volcano that may have formed by collapse after a large volume of andesite was erupted from vents along the caldera rim. However, the distribution of late Pleistocene vents, mostly concentrated along the rim, suggests that ring faults already existed when most of the andesite erupted. No single large eruption has been related to caldera formation. The only eruption recognized to have produced ash flow tuff occurred in late Pleistocene time, and this eruption was too small to account for formation of the caldera. Later conclusions were that Medicine Lake caldera formed by collapse in response to repeated extrusions of mostly mafic lava beginning early in the history of the volcano (perhaps in a manner similar to the formation of Kilauea caldera in Hawaii). Several small differentiated magma bodies may have been fed by and interspersed among a plexus of dikes and sills. Late Holocene andesitic to rhyolitic lavas were derived by fractionation, assimilation, and mixing from high alumina basalt parental magma. The small lake from which Medicine Lake volcano derives its name lies within the central caldera. A topographical summit is a point on a surface which is higher in elevation than all points immediately adjacent to it. ...
A sample of andesite (dark groundmass) with amygdaloidal vesicules filled with zeolite. ...
The Pleistocene epoch (IPA: ) is part of the geologic timescale. ...
Diamond Head, a well-known backdrop to Waikiki in Hawaii, is an ash cone that solidified into tuff Volcanic ash is the term for very fine rock and mineral particles less than 2 mm in diameter that are ejected from a volcanic vent. ...
Welded tuff at Golden Gate in Yellowstone National Park Tuff (from the Italian tufo and pronounced tuf) is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. ...
KÄ«lauea is an active volcano in the Hawaiian Islands, one of five shield volcanoes that together form the Island of Hawaii. ...
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A dike in geology refers to a tabular intrusive igneous body. ...
In geology, a sill is a tabular, often horizontal mass of igneous rock that has been intruded laterally between older layers of sedimentary rock, beds of volcanic lava or tuff, or even along the direction of foliation in metamorphic rock. ...
The Holocene epoch is a geological period that extends from the present back about 10,000 radiocarbon years. ...
Eruptive history
Early history Medicine Lake Volcano began to grow about one million years ago in Pleistocene time, following the eruption of a large volume of tholeiitic high-alumina basalt. Similar high-alumina basalt has continued to erupt around the volcano throughout its history. Although mafic lavas predominate on the volcano's flanks, all lava compositions from basalt to rhyolite have erupted during Pleistocene time. The lower flanks consist of mostly basaltic and some andesitic lavas. Basalt is mostly absent at higher elevation, where andesite dominates and rhyolite and small volumes of dacite are present. During the past 11,000 years, eruptive activity at Medicine Lake Volcano has been episodic. Eight eruptions produced about 5.3 cubic kilometers of basaltic lava during a time interval of a few hundred years about 10,500 years ago. That eruptive episode was followed by a hiatus that ended with a small andesitic eruption about 4,300 years ago. During the most recent eruptive episode between 3000 and 900 years ago, eight eruptions produced approximately 2.5 cubic km of lava ranging in composition from basalt to rhyolite. Late Holocene lava compositions include basalt and andesite, but silicic lavas dominate. The Pleistocene epoch (IPA: ) is part of the geologic timescale. ...
Aluminium oxide (or aluminum oxide) (Al2O3) is a chemical compound of aluminium and oxygen. ...
In geology, mafic minerals and rocks are silicate minerals, magmas, and volcanic and intrusive igneous rocks that have relatively high concentrations of the heavier elements. ...
Rhyolite This page is about a volcanic rock. ...
The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ...
Eruptive activity during Holocene time has included numerous rhyolite and dacite lava flows erupted at high elevations inside and outside the caldera; cinder cones and associated lava flows of basalt and basaltic andesite have resulted from eruptions at vents on the flanks of the shield. Most vents are aligned along zones of crustal weakness that trend NNE to NNW. The Holocene epoch is a geological period that extends from the present back about 10,000 radiocarbon years. ...
Glass Mountain
 Glass Mountain from Medicine Lake caldera rim. USGS photo by Julie Donnelly-Nolan. The most recent eruption occurred around 1,000 years ago when rhyolite and dacite erupted at Glass Mountain and associated vents near the caldera's eastern rim. No field evidence has been found to substantiate a report of an eruption in 1910. Image File history File links Glass_Mountain. ...
Image File history File links Glass_Mountain. ...
Rhyolite This page is about a volcanic rock. ...
Gray, red, black, altered white/tan, flow-banded pumice dacite Dacite is a high-silica igneous, volcanic rock. ...
Glass Mountain consists of a spectacular, nearly treeless, steep-sided rhyolite and dacite obsidian flow that erupted just outside the eastern caldera rim and flowed down the steep eastern flank of Medicine Lake Volcano. Ten additional small domes of Glass Mountain rhyolite and rhyodacite lava lie on a N25degreesW trend to the north and one to the south. The age of Glass Mountain and its preceding pumice deposits has been a matter of discussion for some time. A radiocarbon dating age of 885+/-40 years before present (1990) was obtained on a dead incense-cedar tree without limbs or bark that is preserved in the edge of one of the distal tongues of the flow. The dated material consisted of a piece of exterior wood containing about 30 annual growth rings. This age may be too old, because some of the outside of the tree is missing. The tephra deposits that precede the flow and domes may be somewhat older but are constrained to be less than about 1050 years before present (1990) by the Little Glass Mountain and Lassen Peak data. The coniferous Coast Redwood, the tallest tree species on earth. ...
Obsidian from Lake County, Oregon Top stone is obsidian, below that is pumice and in lower right hand is rhyolite (light color) Obsidian is a type of naturally occurring glass, produced by volcanoes (igneous origin) when a felsic lava cools rapidly and freezes without sufficient time for crystal growth (see...
Radiocarbon dating is a radiometric dating method that uses the naturally occurring isotope carbon-14 to determine the age of carbonaceous materials up to ca 60,000 years. ...
Species Calocedrus decurrens Conservation status: Secure Calocedrus formosana Conservation status: Vulnerable Calocedrus macrolepis Conservation status: Vulnerable The Incense-cedars, Calocedrus, are a genus of two to three species of coniferous trees in the cypress family Cupressaceae. ...
Tephra refers to air-fall material produced by a volcanic eruption regardless of composition or fragment size. ...
Lassen Peak, in Shasta County, California USA, is the largest single lava dome volcano also known as a plug dome in the world and is the southernmost volcano in the Cascade Range. ...
Reference - Adapted from USGS text assumed to be in the public domain. [1]
External links - Medicine Lake Highland Sacred Land Film Project
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