Southwest U.S. Region Mountain
... Its subduction built most of the North American Cordillera, bunching up the west end of the North American plate like folds It is also the origin of the Sierra Nevada Batholith via subduction under North America ...
... Its subduction built most of the North American Cordillera, bunching up the west end of the North American plate like folds It is also the origin of the Sierra Nevada Batholith via subduction under North America ...
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. ...
plate tectonics
... 3) Early evidence for continental drift 4) Continental drift and paleomagnetism 5) Plate boundaries 6) History and future of plate motions 7) Mantle convection system ...
... 3) Early evidence for continental drift 4) Continental drift and paleomagnetism 5) Plate boundaries 6) History and future of plate motions 7) Mantle convection system ...
Tertiary stratigraphy and tectonic evolution of southern Sumatra
... middle Eocene, Southeast Asia from western Sumatra to at least eastern Java was in contact with the slow, northwest moving, Australian Plate, with a velocity of only a couple of cm/yr, rather than the fast, northward moving, Indian Plate with a velocity of about 15 cm/yr. The contact between the Aus ...
... middle Eocene, Southeast Asia from western Sumatra to at least eastern Java was in contact with the slow, northwest moving, Australian Plate, with a velocity of only a couple of cm/yr, rather than the fast, northward moving, Indian Plate with a velocity of about 15 cm/yr. The contact between the Aus ...
Tomographic evidence for hydrated oceanic crust of the Pacific slab
... a thickness of 10 km exists in all cross sections at the uppermost part of the Pacific slab down to depths of 70– 90 km. At these depths, a low-velocity zone emerges immediately above the Pacific slab sub-parallel to the dip of the subducting slab in lines A and B, though it is not clear in lines C ...
... a thickness of 10 km exists in all cross sections at the uppermost part of the Pacific slab down to depths of 70– 90 km. At these depths, a low-velocity zone emerges immediately above the Pacific slab sub-parallel to the dip of the subducting slab in lines A and B, though it is not clear in lines C ...
(43.5-46°S): Implications for Magma Genesis
... solids during solidification. Different ascent rates of magmas in the SSVZ may reflect in part the complexities in the subduction process associated with the subduction of the younger and more fractured oceanic crust just north of the Chile Rise, or they may result, as in the southern part of the Ce ...
... solids during solidification. Different ascent rates of magmas in the SSVZ may reflect in part the complexities in the subduction process associated with the subduction of the younger and more fractured oceanic crust just north of the Chile Rise, or they may result, as in the southern part of the Ce ...
Seismic reflection image of the Great Sumatra
... On the Indo-Australian plate, the highly reflective top of the basalt is capped by a thin layer of pelagic sediment, in turn covered by a thick, landward thickening (2.1 to 3.16 s) turbidite sequence (Figure 2, Supplementary Figure 1). The oceanic Moho is clearly imaged, which provides a crustal thi ...
... On the Indo-Australian plate, the highly reflective top of the basalt is capped by a thin layer of pelagic sediment, in turn covered by a thick, landward thickening (2.1 to 3.16 s) turbidite sequence (Figure 2, Supplementary Figure 1). The oceanic Moho is clearly imaged, which provides a crustal thi ...
pdf-file - Art Periods
... segmented into three main morphotectonic units (from west to east): the coastal Cordillera, Central Valley, and Main Cordillera, where the active volcanic arc is located (Charrier et al., 2007). From surface geology observations, the Central Valley seems to be absent in the Villarrica region between ...
... segmented into three main morphotectonic units (from west to east): the coastal Cordillera, Central Valley, and Main Cordillera, where the active volcanic arc is located (Charrier et al., 2007). From surface geology observations, the Central Valley seems to be absent in the Villarrica region between ...
The anatomy and ontogeny of modern intra
... long as plate tectonics has operated. IOASs’ crustal profiles are wedge-shaped, with crust up to 20–35 km thick; a more useful definition is that IOASs occur as chains of small islands, generally just the tops of the largest volcanoes. A very small fraction of IOASs lie above sea level, but advancin ...
... long as plate tectonics has operated. IOASs’ crustal profiles are wedge-shaped, with crust up to 20–35 km thick; a more useful definition is that IOASs occur as chains of small islands, generally just the tops of the largest volcanoes. A very small fraction of IOASs lie above sea level, but advancin ...
replace this sentence with the title of your abstract
... Dept. of Earth and Planetary Sciences, Washington University, St. Louis. E-mail: [email protected]. 2Hawaii Inst. of Geophysics and Planetology, U. Hawaii. The early differentiation of the Moon generated a crust strongly enriched in alumina as well as trace elements that are incompatible in basaltic sys ...
... Dept. of Earth and Planetary Sciences, Washington University, St. Louis. E-mail: [email protected]. 2Hawaii Inst. of Geophysics and Planetology, U. Hawaii. The early differentiation of the Moon generated a crust strongly enriched in alumina as well as trace elements that are incompatible in basaltic sys ...
topic_4_5 - Earth and Environmental Sciences
... plate during subduction. Arcs are hotter than old oceanic plates, which generally are about 100 km thick and have undergone extensive cooling, losing heat to the oceans by conduction and hydrothermal convection. The hottest geotherms are for oceanic spreading centers, where hot mantle material rises ...
... plate during subduction. Arcs are hotter than old oceanic plates, which generally are about 100 km thick and have undergone extensive cooling, losing heat to the oceans by conduction and hydrothermal convection. The hottest geotherms are for oceanic spreading centers, where hot mantle material rises ...
A narrowly spaced double-seismic zone in the subducting Nazca plate
... crust by hydrothermal circulation at mid-ocean ridges. Hydration processes in the mantle may be stimulated by normal faulting beneath outer rises [Peacock, 2001], the existence of volatile rich mantle plumes [Seno and Yamanaka, 1996], and/or the cooling history of the oceanic plate [Wang, 2002]. Thi ...
... crust by hydrothermal circulation at mid-ocean ridges. Hydration processes in the mantle may be stimulated by normal faulting beneath outer rises [Peacock, 2001], the existence of volatile rich mantle plumes [Seno and Yamanaka, 1996], and/or the cooling history of the oceanic plate [Wang, 2002]. Thi ...
In-Situ Plate Tectonic Model of the Gulf of Mexico (GOM) and
... recently discovered offshore in the Walton Basin (Figure 1). 4. Predicts low chance of reservoir. This prediction is illustrated by Cuba but not by Jamaica, as Palaeocene to Eocene non-volcanic sandstones with a strong lithological similarity to the neighbouring Nicaraguan Rise has been intersected ...
... recently discovered offshore in the Walton Basin (Figure 1). 4. Predicts low chance of reservoir. This prediction is illustrated by Cuba but not by Jamaica, as Palaeocene to Eocene non-volcanic sandstones with a strong lithological similarity to the neighbouring Nicaraguan Rise has been intersected ...
The Early Cretaceous Arperos oceanic basin
... oceanic basin by Freydier et al. and therefore, it constitutes neither a continental, nor oceanic basement for the latter unit. More recently, high-grade gneiss xenoliths with Sm–Nd model ages typical of Grenvillian age rocks in Mexico have been reported as extruded samples of the crust underlying t ...
... oceanic basin by Freydier et al. and therefore, it constitutes neither a continental, nor oceanic basement for the latter unit. More recently, high-grade gneiss xenoliths with Sm–Nd model ages typical of Grenvillian age rocks in Mexico have been reported as extruded samples of the crust underlying t ...
and island arcs
... • CVZ - Precambrian metamorphic crust, 50-75 km thick • SVZ - Accreted Mesozoic and Cenozoic oceanic crust and island arcs,, 30-45 km thick These are separated by inactive gaps. This belt of igneous rocks developed over last 500 Ma and is commonly termed an Andeantype margin. Image source: Winter, 2 ...
... • CVZ - Precambrian metamorphic crust, 50-75 km thick • SVZ - Accreted Mesozoic and Cenozoic oceanic crust and island arcs,, 30-45 km thick These are separated by inactive gaps. This belt of igneous rocks developed over last 500 Ma and is commonly termed an Andeantype margin. Image source: Winter, 2 ...
Moho comparison
... Antilles are somewhat similar. (4) The South American continent is quite homogeneous in terms of velocity and crustal thickness, except it is ~8 km thicker along profile 64W. (5) The average Caribbean arc crust is consistently ~0.25 km/s faster than the S.A. continent, but similar to the global aver ...
... Antilles are somewhat similar. (4) The South American continent is quite homogeneous in terms of velocity and crustal thickness, except it is ~8 km thicker along profile 64W. (5) The average Caribbean arc crust is consistently ~0.25 km/s faster than the S.A. continent, but similar to the global aver ...
High pore pressures and porosity at 35 km depth in the Cascadia
... large amounts of hydrous fluids are produced from subducted materials as a result of prograde metamorphic dehydration reactions (e.g., Peacock, 2004), but how much free H2O exists at depth in subduction zones? Does H2O produced by metamorphic dehydration reactions escape upward rapidly or does the H ...
... large amounts of hydrous fluids are produced from subducted materials as a result of prograde metamorphic dehydration reactions (e.g., Peacock, 2004), but how much free H2O exists at depth in subduction zones? Does H2O produced by metamorphic dehydration reactions escape upward rapidly or does the H ...
12.710, Spring 2014, Problem Set 5, Isostacy Isostacy is the concept
... depth below sea level of the spreading ridge axis is 2.5 km, and the depth of the sea floor away from the ridge axis above 50-million year-old lithosphere is 4.0 km. We want to estimate the thickness of the 50 m.y. old lithosphere. Assume that the density of the crust is 2800 kg/m3, the density of s ...
... depth below sea level of the spreading ridge axis is 2.5 km, and the depth of the sea floor away from the ridge axis above 50-million year-old lithosphere is 4.0 km. We want to estimate the thickness of the 50 m.y. old lithosphere. Assume that the density of the crust is 2800 kg/m3, the density of s ...
The California Arc: Thick Granitic Batholiths, Eclogitic Residues
... show that a significant fraction of the crust (~33 km) in the central Sierra Nevada batholith is granitic, requiring that the batholith be underlain by a significant residual mass prior to Cenozoic extension. Although batholith residua are commonly thought to be granulites, xenolith data indicate th ...
... show that a significant fraction of the crust (~33 km) in the central Sierra Nevada batholith is granitic, requiring that the batholith be underlain by a significant residual mass prior to Cenozoic extension. Although batholith residua are commonly thought to be granulites, xenolith data indicate th ...
ferrari answers
... a detached slab initially produce more or less seismicity as it continued to descend into the mantle, and are there any other proposed active detachments where this might be studied? Not only the detached part of the slab is aseismic (and hence only seen by seismic tomography) but also the leading e ...
... a detached slab initially produce more or less seismicity as it continued to descend into the mantle, and are there any other proposed active detachments where this might be studied? Not only the detached part of the slab is aseismic (and hence only seen by seismic tomography) but also the leading e ...
Pacific microplate and the Pangea supercontinent in the Early to
... the Pacific plate. The Pacific-Farallon spreading ridge rotated clockwise about 208 at M10N time (130 Ma) and at the same time the PacificPhoenix spreading ridge propagated an additional 700 km into what is now the Central Pacific Basin (Nakanishi et al., 1992). Sometime between M14 and M11 the Mage ...
... the Pacific plate. The Pacific-Farallon spreading ridge rotated clockwise about 208 at M10N time (130 Ma) and at the same time the PacificPhoenix spreading ridge propagated an additional 700 km into what is now the Central Pacific Basin (Nakanishi et al., 1992). Sometime between M14 and M11 the Mage ...
Presnall, D. C. (1980) A double partial melt zone in the mantle beneath mid-ocean ridges, Phys. Earth Planet. Int., 23, 103-111.
... 1978; Walker eta!., 1978) and Anderson and Minster (1980) have pointed out that the thickness of the lithosphere depends on whether seismic, thermal, or rheological properties are being considered. It will be seen in the following discussion that if the model of Presnall et a!. (1979) for the genera ...
... 1978; Walker eta!., 1978) and Anderson and Minster (1980) have pointed out that the thickness of the lithosphere depends on whether seismic, thermal, or rheological properties are being considered. It will be seen in the following discussion that if the model of Presnall et a!. (1979) for the genera ...
Convergent Plates - Earthquake Explorers
... 1. What type of tectonic plate boundary is found where the Nazca plate meets the South American plate? (i.e. name the boundary type) ______________________________________________________________ 2. What type of crustal material is present in the (i.e. oceanic or continental): (a) Nazca plate: _____ ...
... 1. What type of tectonic plate boundary is found where the Nazca plate meets the South American plate? (i.e. name the boundary type) ______________________________________________________________ 2. What type of crustal material is present in the (i.e. oceanic or continental): (a) Nazca plate: _____ ...
Lesson 2: “Seafloor Spreading”
... varying depths of the ocean. This is known as “sonar” today. 2. While using this method of echo location, they discovered an underwater system of ____________________ (mountains) and ____________________. 3. In the Atlantic, Pacific, and other oceans around the world are a system of ridges called “_ ...
... varying depths of the ocean. This is known as “sonar” today. 2. While using this method of echo location, they discovered an underwater system of ____________________ (mountains) and ____________________. 3. In the Atlantic, Pacific, and other oceans around the world are a system of ridges called “_ ...
Fluid Processes in Subduction Zones Hydrous Minerals and
... • Buoyancy will tend to isolate forearc wedge from corner flow • Heating of hydrated forearc mantle (e.g., ridge subduction, post-subduction) will release significant amounts of H2O ...
... • Buoyancy will tend to isolate forearc wedge from corner flow • Heating of hydrated forearc mantle (e.g., ridge subduction, post-subduction) will release significant amounts of H2O ...
Izu-Bonin-Mariana Arc
The Izu-Bonin-Mariana (IBM) arc system is an outstanding example of a plate tectonic convergent boundary. IBM extends over 2800 km south from Tokyo, Japan, to beyond Guam, and includes the Izu Islands, Bonin Islands, and Mariana Islands; much more of the IBM arc system is submerged below sealevel. The IBM arc system lies along the eastern margin of the Philippine Sea Plate in the Western Pacific Ocean. It is most famous for being the site of the deepest gash in Earth's solid surface, the Challenger Deep in the Mariana Trench. The IBM arc system formed as a result of subduction of the western Pacific plate. The IBM arc system now subducts mid-Jurassic to Early Cretaceous lithosphere, with younger lithosphere in the north and older lithosphere in the south, including the oldest (~170 million years old, or Ma) oceanic crust. Subduction rates vary from ~2 cm (1 inch) per year in the south to 6 cm (~2.5 inches) in the north. The volcanic islands that comprise these island arcs are thought to have been formed from the release of volatiles (steam from trapped water, and other gases) being released from the subducted plate, as it reached sufficient depth for the temperature to cause release of these materials. The associated trenches are formed as the oldest (most western) part of the Pacific plate crust increases in density with age, and because of this process finally reaches its lowest point just as it subducts under the crust to the west of it.The IBM arc system is an excellent example of an intra-oceanic convergent margin (IOCM). IOCMs are built on oceanic crust and contrast fundamentally with island arc built on continental crust, such as Japan or the Andes. Because IOCM crust is thinner, denser, and more refractory than that beneath Andean-type margins, study of IOCM melts and fluids allows more confident assessment of mantle-to-crust fluxes and processes than is possible for Andean-type convergent margins. Because IOCMs are far removed from continents they are not affected by the large volume of alluvial and glacial sediments. The consequent thin sedimentary cover makes it much easier to study arc infrastructure and determine the mass and composition of subducted sediments. Active hydrothermal systems found on the submarine parts of IOCMs give us a chance to study how many of earth's important ore deposits formed.