Developing the plate tectonics from oceanic subduction to
... orogenic continental lithosphere and exhumation of metamorphic core complexes upon tectonic collapse. Nevertheless, there is a significant difference in the exhumation rate of UHP terranes between the two types of collision. Fast exhumation (>20 mm/yr) commonly took place in the Himalaya-Tibet type, ...
... orogenic continental lithosphere and exhumation of metamorphic core complexes upon tectonic collapse. Nevertheless, there is a significant difference in the exhumation rate of UHP terranes between the two types of collision. Fast exhumation (>20 mm/yr) commonly took place in the Himalaya-Tibet type, ...
Formation and Exhumation of Ultrahigh
... moderate temperatures (<800 °C) observed in most continental UHP terranes. The need for such cool temperatures to be maintained by either continued, deeper-level subduction refrigeration or rapid, near-adiabatic exhumation has led to the general dominance of a single model. In this model, a relative ...
... moderate temperatures (<800 °C) observed in most continental UHP terranes. The need for such cool temperatures to be maintained by either continued, deeper-level subduction refrigeration or rapid, near-adiabatic exhumation has led to the general dominance of a single model. In this model, a relative ...
Seamounts, New - The Center for Coastal and Ocean Mapping
... margin of the Mariana Arc, and the Mariana Trough and West Mariana Ridge lie to the west. Four cruises of 30 days each were devoted to the Mariana Islands region, two focused on the West Mariana Ridge, one on the eastern margin and trench, and one on the southern margin and trench. For these cruises ...
... margin of the Mariana Arc, and the Mariana Trough and West Mariana Ridge lie to the west. Four cruises of 30 days each were devoted to the Mariana Islands region, two focused on the West Mariana Ridge, one on the eastern margin and trench, and one on the southern margin and trench. For these cruises ...
117. Lee, C. - Cin
... arth is the only known planet in the solar system with continents and ocean basins. The continents ride high, about four kilometres above the seafloor. They are composed of thick, silicic crust that is more buoyant than the thin, dense crust that floors the oceans. Oceanic crust is thin — only about ...
... arth is the only known planet in the solar system with continents and ocean basins. The continents ride high, about four kilometres above the seafloor. They are composed of thick, silicic crust that is more buoyant than the thin, dense crust that floors the oceans. Oceanic crust is thin — only about ...
Plateau uplift in western Canada caused by lithospheric
... show that, west of the RMT, the upper mantle is fertile in composition14 (that is, similar to Mid-Ocean Ridge Basalt, MORB), in contrast to melt-depleted compositions of nearby cratonic xenoliths15 . Medium- to high-temperature thermochronological data record variations in cooling rate that constrai ...
... show that, west of the RMT, the upper mantle is fertile in composition14 (that is, similar to Mid-Ocean Ridge Basalt, MORB), in contrast to melt-depleted compositions of nearby cratonic xenoliths15 . Medium- to high-temperature thermochronological data record variations in cooling rate that constrai ...
Earth-9th-Edition-Tarbuck-Test-Bank
... 11) During the geologic past, the magnetic field poles have generally been very close to Earth's rotational poles. Answer: TRUE Diff: 1 ...
... 11) During the geologic past, the magnetic field poles have generally been very close to Earth's rotational poles. Answer: TRUE Diff: 1 ...
the caribbean plate and the question of its formation
... arcs (Greater Antilles, Lesser Antilles etc.) consist of Mesozoic and Cenozoic rocks. Mesozoic and Cenozoic sandstones, siltstones and shales, occurring above the metamorphic basement, are the most in common rocks. The main part of the Caribbean plate consists of thickened oceanic crust of a plateau ...
... arcs (Greater Antilles, Lesser Antilles etc.) consist of Mesozoic and Cenozoic rocks. Mesozoic and Cenozoic sandstones, siltstones and shales, occurring above the metamorphic basement, are the most in common rocks. The main part of the Caribbean plate consists of thickened oceanic crust of a plateau ...
Decoupling along plate boundaries: Key variable controlling the
... development of pop-down–type structures similar to those described by Sokoutis et al. (2005). Although the rheological contrast between the weak zone and the adjacent plates is on the order of one magnitude, coupling between the plates is strong, as documented by the lack of shear across the incline ...
... development of pop-down–type structures similar to those described by Sokoutis et al. (2005). Although the rheological contrast between the weak zone and the adjacent plates is on the order of one magnitude, coupling between the plates is strong, as documented by the lack of shear across the incline ...
EARTH SYSTEM SCIENCE II
... convection cell is the length of the horizontal boundary layer currents. Depending on material properties and temperature gradients at the top of the thermal layer, material can only travel so far before sinking/downwelling into the mantle, thus controlling the size. Thermal Boundary Layer Forces: h ...
... convection cell is the length of the horizontal boundary layer currents. Depending on material properties and temperature gradients at the top of the thermal layer, material can only travel so far before sinking/downwelling into the mantle, thus controlling the size. Thermal Boundary Layer Forces: h ...
Chemical Geodynamics
... meaning their long term Lu/Hf and Sm/Nd ratios have been higher than chondritic. But nearly all MORB samples have subchondritic measured Lu/Hf and Sm/Nd ratios. • It follows that Lu/Hf and Sm/Nd were fractionated recently (by the melting process itself), which turns out to requires garnet in the sou ...
... meaning their long term Lu/Hf and Sm/Nd ratios have been higher than chondritic. But nearly all MORB samples have subchondritic measured Lu/Hf and Sm/Nd ratios. • It follows that Lu/Hf and Sm/Nd were fractionated recently (by the melting process itself), which turns out to requires garnet in the sou ...
Major and trace analysis of basaltic glasses by laser-ablation ICP-MS
... [1] We use the Multipole–Boundary Element Method (MP-BEM) to simulate regional and global geodynamics in a spherical 3-D setting. We first simulate an isolated subducting rectangular plate with length (Llitho) and width (Wlitho) varying between 0.5 and 2 times the radius of the Earth (REarth) and wi ...
... [1] We use the Multipole–Boundary Element Method (MP-BEM) to simulate regional and global geodynamics in a spherical 3-D setting. We first simulate an isolated subducting rectangular plate with length (Llitho) and width (Wlitho) varying between 0.5 and 2 times the radius of the Earth (REarth) and wi ...
Page 1 Ordovician orogeny in the Alps – a reappraisal Roger
... The Strona-Ceneri zone comprises the deformed and metamorphosed remains of an early Paleozoic subductionaccretion complex with relicts of eclogite facies assemblages that became re-equilibrated under amphibolite facies conditions during the intrusion of peraluminous Ordovician granitoids (Zurbriggen ...
... The Strona-Ceneri zone comprises the deformed and metamorphosed remains of an early Paleozoic subductionaccretion complex with relicts of eclogite facies assemblages that became re-equilibrated under amphibolite facies conditions during the intrusion of peraluminous Ordovician granitoids (Zurbriggen ...
Hafnium isotope evidence for slab melt contributions in the Central
... Volcanic Belt, Cascades, Austral Andes, Luzon, Setouchi), where slab tearing occurred and hot asthenospheric mantle could upwell through the slab window (e.g., western Aleutians, Sunda, southern Scotia), and where oblique or slow subduction leads to higher slab temperatures (e.g. Lesser Antilles, we ...
... Volcanic Belt, Cascades, Austral Andes, Luzon, Setouchi), where slab tearing occurred and hot asthenospheric mantle could upwell through the slab window (e.g., western Aleutians, Sunda, southern Scotia), and where oblique or slow subduction leads to higher slab temperatures (e.g. Lesser Antilles, we ...
Extremely thin crust in the Indian Ocean possibly resulting from
... Seismic reflection image along profile WG3 as a function of twoway traveltime is shown in Fig. 3(a) and the depth converted image using interval velocity obtained from normal moveout velocity in Fig. 3(b). The water depth varies from 4.7 km in the southeast to 4.4 km in the northwest. There are thic ...
... Seismic reflection image along profile WG3 as a function of twoway traveltime is shown in Fig. 3(a) and the depth converted image using interval velocity obtained from normal moveout velocity in Fig. 3(b). The water depth varies from 4.7 km in the southeast to 4.4 km in the northwest. There are thic ...
Earth,Tests,Ch14
... B) developed in response to a continent-continent collision C) are uplifted, blocks that typically have cores of Proterozoic igneous and metamorphic rocks D) the Paleozoic and Mesozoic sedimentary rocks were elevated and compressed into tight folds; but the deeper, harder rocks of the continental cr ...
... B) developed in response to a continent-continent collision C) are uplifted, blocks that typically have cores of Proterozoic igneous and metamorphic rocks D) the Paleozoic and Mesozoic sedimentary rocks were elevated and compressed into tight folds; but the deeper, harder rocks of the continental cr ...
Why is there Lithosphere
... asthenosphere. Because the lithosphere is above the asthenosphere, it is much colder, and behaves differently to applied stresses. Even though the warmer asthenosphere is solid, when stresses are applied it has the ability to flow (i.e., it has a “plastic” or non-rigid nature), and does not fracture ...
... asthenosphere. Because the lithosphere is above the asthenosphere, it is much colder, and behaves differently to applied stresses. Even though the warmer asthenosphere is solid, when stresses are applied it has the ability to flow (i.e., it has a “plastic” or non-rigid nature), and does not fracture ...
The late Paleozoic to Cainozoic intraplate deformation in
... Permian and Triassic sediments is marked by an unconformity. The latter is of regional nature and can be traced in the adjacent areas of Arabia and Sinai. According to F. Hirsh (1990), most of the Lower Triassic section is missing in northern Sinai within a fold belt known as the Syrian arc. The gap ...
... Permian and Triassic sediments is marked by an unconformity. The latter is of regional nature and can be traced in the adjacent areas of Arabia and Sinai. According to F. Hirsh (1990), most of the Lower Triassic section is missing in northern Sinai within a fold belt known as the Syrian arc. The gap ...
Analogue modelling of continental collision: Influence of plate
... et al., 2004a). Far field stresses within the model generated by the moving wall are mostly accommodated within the much thicker ductile layers. Therefore, we limited our predefined weak plate interface to the mantle lithosphere and to keep the influence on the evolving crustal architecture as low as p ...
... et al., 2004a). Far field stresses within the model generated by the moving wall are mostly accommodated within the much thicker ductile layers. Therefore, we limited our predefined weak plate interface to the mantle lithosphere and to keep the influence on the evolving crustal architecture as low as p ...
Upper Mantle Tomographic Vp and Vs Images of the Rocky
... Then spurious travel-times are found and removed when their value is greater than twice the standard variation ( > 2σ ) of the polynomial fit. The last step to identify bad data is via slowness residual analysis (polar plot). The residuals for each station are binned into non-overlapping grids in 2- ...
... Then spurious travel-times are found and removed when their value is greater than twice the standard variation ( > 2σ ) of the polynomial fit. The last step to identify bad data is via slowness residual analysis (polar plot). The residuals for each station are binned into non-overlapping grids in 2- ...
Earth: An Introduction to Physical Geology, 10e (Tarbuck/Lutgens
... 11) During the geologic past, the magnetic field poles have generally been very close to Earth's geographical poles. Answer: TRUE Diff: 1 12) Seafloor spreading rates can be estimated if the geologic ages of the magnetic field reversals are independently known. Answer: TRUE Diff: 2 13) The volcanoes ...
... 11) During the geologic past, the magnetic field poles have generally been very close to Earth's geographical poles. Answer: TRUE Diff: 1 12) Seafloor spreading rates can be estimated if the geologic ages of the magnetic field reversals are independently known. Answer: TRUE Diff: 2 13) The volcanoes ...
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... and the Driving Mechanism of Plate Tectonics Department of Geology a n d Geopbsics, University of California, Berkeley, California 94720 Tectonic features at the earth's surface can be used to test models for mantle return flow and to determine the geographic pattern of this flow. A model with shall ...
... and the Driving Mechanism of Plate Tectonics Department of Geology a n d Geopbsics, University of California, Berkeley, California 94720 Tectonic features at the earth's surface can be used to test models for mantle return flow and to determine the geographic pattern of this flow. A model with shall ...
Paleogeography, Southwestern US
... modern Adaman Sea south of Burma may be an example; the sea is along a transform margin created by oblique collision between the Indian Plate and western SE Asia. No exotic continental block is involved in the tectonic sequences. The more exotic models create ophiolites in back arc basins, mostly as ...
... modern Adaman Sea south of Burma may be an example; the sea is along a transform margin created by oblique collision between the Indian Plate and western SE Asia. No exotic continental block is involved in the tectonic sequences. The more exotic models create ophiolites in back arc basins, mostly as ...
The Bent Hawaiian-Emperor Hotspot Track
... plate motion change (17). Both plate circuits paleomagnetic determinations from ocean large volume flux (~350 m3 s−1) (21), spatial pass paleomagnetic consistency tests (14); we drilling (1, 8). pattern, and longevity are best explained by the cannot distinguish between them with the mantle plume hy ...
... plate motion change (17). Both plate circuits paleomagnetic determinations from ocean large volume flux (~350 m3 s−1) (21), spatial pass paleomagnetic consistency tests (14); we drilling (1, 8). pattern, and longevity are best explained by the cannot distinguish between them with the mantle plume hy ...
8 Multiple plate collisions and the end of the Iapetus Ocean
... from the sense of rotation of fabric components into the fault or shear zone. During oblique convergence or collision, material is moved along the orogen. In reality, the style and location of structures that develop along a collisional plate boundary are a function of a variety of factors, includin ...
... from the sense of rotation of fabric components into the fault or shear zone. During oblique convergence or collision, material is moved along the orogen. In reality, the style and location of structures that develop along a collisional plate boundary are a function of a variety of factors, includin ...
Oceanic trench
The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few mm to over ten cm per year. A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to a volcanic island arc, and about 200 km (120 mi) from a volcanic arc. Oceanic trenches typically extend 3 to 4 km (1.9 to 2.5 mi) below the level of the surrounding oceanic floor. The greatest ocean depth to be sounded is in the Challenger Deep of the Mariana Trench, at a depth of 11,034 m (36,201 ft) below sea level. Oceanic lithosphere moves into trenches at a global rate of about 3 km2/yr.