Crustal contributions to arc magmatism in the Andes of Central Chile
... Twelve of the 15 have erupted in Holocene time, and only Tupungato, Cerro Alto, Cerro Sordo Lucas and (perhaps) Palomo are thought to be extinct. At the north end of the segment, the volcanoes form a narrow chain along the Andean crest, attaining summit elevations of 5 to 6.5 kin. From 34.5~ southwa ...
... Twelve of the 15 have erupted in Holocene time, and only Tupungato, Cerro Alto, Cerro Sordo Lucas and (perhaps) Palomo are thought to be extinct. At the north end of the segment, the volcanoes form a narrow chain along the Andean crest, attaining summit elevations of 5 to 6.5 kin. From 34.5~ southwa ...
The volcanic–plutonic connection as a stage for
... (Lindsay et al., 2001; Bachmann et al., 2002; Maughan et al., 2002), a rare assemblage in crystal-poor volcanic rocks (Nakada, 1991; Deer et al., 1992) but common in granodiorite batholiths (e.g., Bateman and Chappell, 1979). One noticeable difference is the higher abundance of quartz and K-feldspar ...
... (Lindsay et al., 2001; Bachmann et al., 2002; Maughan et al., 2002), a rare assemblage in crystal-poor volcanic rocks (Nakada, 1991; Deer et al., 1992) but common in granodiorite batholiths (e.g., Bateman and Chappell, 1979). One noticeable difference is the higher abundance of quartz and K-feldspar ...
VIRTUAL FIELD TRIP
... eruption depends on how easy magma can flow and the amount of gas trapped in it. When a volcano erupts, the magma goes up to the earth’s surface. The magma that goes up to earth surface is called Lava. Magma is the molten rock within the earth’s crust. Rock also come from the volcanoes in different ...
... eruption depends on how easy magma can flow and the amount of gas trapped in it. When a volcano erupts, the magma goes up to the earth’s surface. The magma that goes up to earth surface is called Lava. Magma is the molten rock within the earth’s crust. Rock also come from the volcanoes in different ...
Petrogenesis and correlation of the mid
... erupted from the Mt. Princeton pluton. The Badger Creek tuff (34 Ma) is believed to be from the Mt. Aetna caldera, which was developed above the Mt. Princeton pluton (Shannon, 1988). The Grizzly Peak caldera lies further to the north but has not yet been correlated with a major ash flow. Varga and S ...
... erupted from the Mt. Princeton pluton. The Badger Creek tuff (34 Ma) is believed to be from the Mt. Aetna caldera, which was developed above the Mt. Princeton pluton (Shannon, 1988). The Grizzly Peak caldera lies further to the north but has not yet been correlated with a major ash flow. Varga and S ...
rifting of the plate boundary in north iceland 1975-1978
... period of 100 to 150 years. During each active period, which probably lasts 5 to 20 years, only one central volcano and fissure swarm is active (Bjornsson et al. 1977). The Krafla fissure swarm, which is presently active, extends from the Tjornes Fracture Zone in the Axarfjordur bay in the north and ...
... period of 100 to 150 years. During each active period, which probably lasts 5 to 20 years, only one central volcano and fissure swarm is active (Bjornsson et al. 1977). The Krafla fissure swarm, which is presently active, extends from the Tjornes Fracture Zone in the Axarfjordur bay in the north and ...
"lost Inca Plateau": cause of flat subduction - Archimer
... moat infill (240,000 km3) is 2.5 times greater than the young volcanic edifices (90,000 km 3) [7] and of comparable thickness at the NW corner of the plateau (volcanism > 5 Ma) as at the SE corner of the plateau (volcanism ca. 0.5 Ma). Thus, it appears impossible that a) the moat fill represents onl ...
... moat infill (240,000 km3) is 2.5 times greater than the young volcanic edifices (90,000 km 3) [7] and of comparable thickness at the NW corner of the plateau (volcanism > 5 Ma) as at the SE corner of the plateau (volcanism ca. 0.5 Ma). Thus, it appears impossible that a) the moat fill represents onl ...
Understanding the 3D Structure of the Gilmore Fault Zone Through
... locus of orogenesis, generally young from west to east. The WMB dominates the central zone and the eastern zone is characterised by a series of Silurian-to Devonian rift basins (e.g., the Tumut Trough, which is adjacent to the GFZ) and granite batholiths developed on a Cambro-Ordovician basement. Th ...
... locus of orogenesis, generally young from west to east. The WMB dominates the central zone and the eastern zone is characterised by a series of Silurian-to Devonian rift basins (e.g., the Tumut Trough, which is adjacent to the GFZ) and granite batholiths developed on a Cambro-Ordovician basement. Th ...
Epithermal gold-copper mineralization associated with Late
... to diorite and andesite intrusions of which the latter are cut by nearly vertical gold-bearing quartz veins in deeper zones and covered by a siliceous cap in the upper zones. High sulfidation epithermal mineralization has been documented in northern Sumatra (van Leeuwen, 1994) and southwestern Lombo ...
... to diorite and andesite intrusions of which the latter are cut by nearly vertical gold-bearing quartz veins in deeper zones and covered by a siliceous cap in the upper zones. High sulfidation epithermal mineralization has been documented in northern Sumatra (van Leeuwen, 1994) and southwestern Lombo ...
Consisting of the Orange 7.5-Minute Quadrangle
... Pauchaug Brook, which enters the Connecticut River in New Hampshire just north of Northfield, Massachusetts. In the Orange area and adjacent areas to the north, the Pauchaug Gneiss has been divided on a rather subjective basis into a more massive core and a finegrained more foliated rim. The gneiss ...
... Pauchaug Brook, which enters the Connecticut River in New Hampshire just north of Northfield, Massachusetts. In the Orange area and adjacent areas to the north, the Pauchaug Gneiss has been divided on a rather subjective basis into a more massive core and a finegrained more foliated rim. The gneiss ...
Research Focus: Crust formation in the western United
... resolution of the controversy. For example, inherited zircons in plutonic and volcanic rocks simply indicate that there was “communication” between older continental crust and the locus of magma production. The presence of inherited zircons does not require that older crust exists either in the area ...
... resolution of the controversy. For example, inherited zircons in plutonic and volcanic rocks simply indicate that there was “communication” between older continental crust and the locus of magma production. The presence of inherited zircons does not require that older crust exists either in the area ...
Validation of OMI L2 Sulfur Dioxide retrievals over volcanic
... the 7.3 µm waveband used to retrieve SO2 column abundance from AIRS measurements, AIRS usually only detects volcanic SO2 in the upper troposphere and lower stratosphere (UTLS) or above. We have assembled a list of eruptions detected by both OMI and AIRS in the same ATrain overpass for comparisons (T ...
... the 7.3 µm waveband used to retrieve SO2 column abundance from AIRS measurements, AIRS usually only detects volcanic SO2 in the upper troposphere and lower stratosphere (UTLS) or above. We have assembled a list of eruptions detected by both OMI and AIRS in the same ATrain overpass for comparisons (T ...
culzean harbour
... similar relationship is well displayed in the southern wall of a raised sea-arch close to the southern end of the GCR site (2271 1000), where the pillowed lobes at the base of another andesite sheet protrude into sandstone. Amygdales and veins of agate and quartz within feldspar-phyric andesite are ...
... similar relationship is well displayed in the southern wall of a raised sea-arch close to the southern end of the GCR site (2271 1000), where the pillowed lobes at the base of another andesite sheet protrude into sandstone. Amygdales and veins of agate and quartz within feldspar-phyric andesite are ...
as a PDF
... transfer of frictional heat from the flowing water to the ice walls (loss of potential energy). Under the assumption of instantaneous heat transfer, water would emerge at the river outlet at the melting point, as is generally observed in jökulhlaups in Iceland, whereas the heat transfer equation wo ...
... transfer of frictional heat from the flowing water to the ice walls (loss of potential energy). Under the assumption of instantaneous heat transfer, water would emerge at the river outlet at the melting point, as is generally observed in jökulhlaups in Iceland, whereas the heat transfer equation wo ...
calcalk13
... (South Pacific arcs), which fall in the cpx-out field with OIB and flood high magnesian lavas in a plot of Al versus Si. Although the occurrence of low-Al ankaramites is relatively rare in calcalkaline volcanic suites, they do have compositions that can coexist with the mantle, and some have suggest ...
... (South Pacific arcs), which fall in the cpx-out field with OIB and flood high magnesian lavas in a plot of Al versus Si. Although the occurrence of low-Al ankaramites is relatively rare in calcalkaline volcanic suites, they do have compositions that can coexist with the mantle, and some have suggest ...
GEO100 05 plate tectonics
... The lithosphere is divided into plates that move relative to one another, and relative to the earth’s asthenosphere. Movement occurs at very slow (cm/yr) rates. As a plate moves, its interior remains relatively intact (but it is not totally ridged) while its boundaries become deformed. ...
... The lithosphere is divided into plates that move relative to one another, and relative to the earth’s asthenosphere. Movement occurs at very slow (cm/yr) rates. As a plate moves, its interior remains relatively intact (but it is not totally ridged) while its boundaries become deformed. ...
The role of lower continental crust and lithospheric mantle in the
... zoic European volcanic rocks do not seem to record, up to now, even older modi¢cations such as those related to the Panafrican and the Hercynian orogenies. During these events (late Proterozoic and late Palaeozoic, respectively), complex interaction among various mantle domains and crustal lithologi ...
... zoic European volcanic rocks do not seem to record, up to now, even older modi¢cations such as those related to the Panafrican and the Hercynian orogenies. During these events (late Proterozoic and late Palaeozoic, respectively), complex interaction among various mantle domains and crustal lithologi ...
Geothermal Development in Eritrea
... by post caldera rhyolitic obsidian domes and basaltic lava eruptions inside the caldera and on its flanks. Some very recent lava flows were erupted along NNW trending fissures and transverse to the trend of the Nabbro-Dubbi volcanic range (Figure 9). Dubbi is a large volcanic mass that rises 1625 m ...
... by post caldera rhyolitic obsidian domes and basaltic lava eruptions inside the caldera and on its flanks. Some very recent lava flows were erupted along NNW trending fissures and transverse to the trend of the Nabbro-Dubbi volcanic range (Figure 9). Dubbi is a large volcanic mass that rises 1625 m ...
Physical volcanology of continental large igneous provinces: update
... emplacement and eruption of voluminous magmas ranging from basalt to rhyolite in composition. Continental flood basalt provinces are the best studied LIPs and consist of crustal intrusive systems, extensive flood lavas and ignimbrites, and mafic volcaniclastic deposits in varying proportions. Intrus ...
... emplacement and eruption of voluminous magmas ranging from basalt to rhyolite in composition. Continental flood basalt provinces are the best studied LIPs and consist of crustal intrusive systems, extensive flood lavas and ignimbrites, and mafic volcaniclastic deposits in varying proportions. Intrus ...
EPSL94HokeHelium3Alt.. - University of Colorado Boulder
... sulfataras and geothermal springs from the Central Andes of northern Chile and Bolivia between the latitudes 15°S and 23°S. The highest 3 H e / 4 H e ratios (reported as R / R A ratios: R = sample 3 H e / 4 H e , R A = air 3 H e / 4 H e ) are associated with the active volcanic arc of the Western Co ...
... sulfataras and geothermal springs from the Central Andes of northern Chile and Bolivia between the latitudes 15°S and 23°S. The highest 3 H e / 4 H e ratios (reported as R / R A ratios: R = sample 3 H e / 4 H e , R A = air 3 H e / 4 H e ) are associated with the active volcanic arc of the Western Co ...
Lava is the molten rock expelled by a volcano during an eruption
... the range of 750 to 950 °C (1,380 to 1,740 °F)), they tend to be less viscous. Greater temperatures tend to destroy polymerized bonds within the magma, promoting more fluid behaviour and also a greater tendency to form phenocrysts. Higher iron and magnesium tends to manifest as a darker groundmass, ...
... the range of 750 to 950 °C (1,380 to 1,740 °F)), they tend to be less viscous. Greater temperatures tend to destroy polymerized bonds within the magma, promoting more fluid behaviour and also a greater tendency to form phenocrysts. Higher iron and magnesium tends to manifest as a darker groundmass, ...
Buckling an orogen: The Cantabrian Orocline
... Figure 3. (A) Block diagram depicting the effect of lithospheric bending around a vertical axis and the resultant strain field (modified tangential longitudinal strain). Strain ellipses depict arc-parallel shortening in the inner arc and arcparallel stretching in the outer arc. Note the different be ...
... Figure 3. (A) Block diagram depicting the effect of lithospheric bending around a vertical axis and the resultant strain field (modified tangential longitudinal strain). Strain ellipses depict arc-parallel shortening in the inner arc and arcparallel stretching in the outer arc. Note the different be ...
The Tiers of Vocabulary - Cattaraugus
... that was required of all voters but was too costly for many blacks and for poor whites as well. Voters also had to pass a literacy test to prove that they could read, write, and understand the U.S. Constitution. These tests were often rigged to disqualify even highly educated blacks. Those who overc ...
... that was required of all voters but was too costly for many blacks and for poor whites as well. Voters also had to pass a literacy test to prove that they could read, write, and understand the U.S. Constitution. These tests were often rigged to disqualify even highly educated blacks. Those who overc ...
(pdf; with prior and figs)
... spreading rate), its proximity to western North America, its shallow (1600 m) summit depth, its prominent (3x8 km wide) caldera (figure 1A), and it vigorous hydrothermal activity have led to its being the focus of numerous research efforts (e.g. the special sections in the Journal of Geophysical Res ...
... spreading rate), its proximity to western North America, its shallow (1600 m) summit depth, its prominent (3x8 km wide) caldera (figure 1A), and it vigorous hydrothermal activity have led to its being the focus of numerous research efforts (e.g. the special sections in the Journal of Geophysical Res ...
EOCENE TECTONIC EVOLUTION OF NW MEXICO (SONORA and
... is the Eocene Poway Conglomerate, which had its source in the area of Tajitos in northern Sonora (Abbott and Smith, 1989). Dealing with the above exposed paleomagnetic data concerning the Poway Conglomerate, Abbott and Smith (1989) stated that “any boundary separating a paleomagnetically defined Baj ...
... is the Eocene Poway Conglomerate, which had its source in the area of Tajitos in northern Sonora (Abbott and Smith, 1989). Dealing with the above exposed paleomagnetic data concerning the Poway Conglomerate, Abbott and Smith (1989) stated that “any boundary separating a paleomagnetically defined Baj ...
High pore pressures and porosity at 35 km depth in the Cascadia
... incoming oceanic crust has relatively high porosities of 5%–10% supported by a crystalline framework, which may persist to greater depths. A more likely source of fluid at 25–45 km depth is metamorphic dehydration reactions. Beginning at shallow levels with the breakdown of clay minerals and extendi ...
... incoming oceanic crust has relatively high porosities of 5%–10% supported by a crystalline framework, which may persist to greater depths. A more likely source of fluid at 25–45 km depth is metamorphic dehydration reactions. Beginning at shallow levels with the breakdown of clay minerals and extendi ...
Cascade Volcanoes
This article is for the volcanic arc. For the namesake mountain range see Cascade Range.The Cascade Volcanoes (also known as the Cascade Volcanic Arc or the Cascade Arc) are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern California, a distance of well over 700 miles (1,100 km). The arc has formed due to subduction along the Cascadia subduction zone. Although taking its name from the Cascade Range, this term is a geologic grouping rather than a geographic one, and the Cascade Volcanoes extend north into the Coast Mountains, past the Fraser River which is the northward limit of the Cascade Range proper.Some of the major cities along the length of the arc include Portland, Seattle, and Vancouver, and the population in the region exceeds 10,000,000. All could be potentially affected by volcanic activity and great subduction-zone earthquakes along the arc. Because the population of the Pacific Northwest is rapidly increasing, the Cascade volcanoes are some of the most dangerous, due to their eruptive history and potential for future eruptions, and because they are underlain by weak, hydrothermally altered volcanic rocks that are susceptible to failure. Consequently, Mount Rainier is one of the Decade Volcanoes identified by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) as being worthy of particular study, due to the danger it poses to Seattle and Tacoma. Many large, long-runout landslides originating on Cascade volcanoes have inundated valleys tens of kilometers from their sources, and some of the inundated areas now support large populations.The Cascade Volcanoes are part of the Pacific Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean. All of the known historic eruptions in the contiguous United States have been from the Cascade Volcanoes. Two most recent were Lassen Peak in 1914 to 1921 and a major eruption of Mount St. Helens in 1980. It is also the site of Canada's most recent major eruption about 2,350 years ago at the Mount Meager volcanic complex.