Laxmi Ridge - Northern Seychelles Bank, Western Indian
... Figure 1 (a) inset: Satellite gravity field for the NW Indian Ocean12 showing the Seychelles (S) and Laxmi Ridge (LR) margins in their present position. Laxmi Ridge is marked by a well-defined gravity low (blue/green). The two roughly triangular regions were reconstructed in (b), red line = cruise t ...
... Figure 1 (a) inset: Satellite gravity field for the NW Indian Ocean12 showing the Seychelles (S) and Laxmi Ridge (LR) margins in their present position. Laxmi Ridge is marked by a well-defined gravity low (blue/green). The two roughly triangular regions were reconstructed in (b), red line = cruise t ...
Thermal Structure due to Solid-State Flow in the Mantle
... changes in thermal models, which make them consistent with PT constraints from the lower crust and uppermost mantle, might also lead to a resolution of the apparent paradox in which geochemistry suggests partial melting of subducted sediment and basalt, while thermal models appear to rule this out. ...
... changes in thermal models, which make them consistent with PT constraints from the lower crust and uppermost mantle, might also lead to a resolution of the apparent paradox in which geochemistry suggests partial melting of subducted sediment and basalt, while thermal models appear to rule this out. ...
Chapter 17 Basins in arc-continent collisions
... et al., 1991). Frontal accretionary prisms, in contrast to underplated material, tend to be deformed but not substantially metamorphosed. The metasedimentary Westport Complex and South Connemara Group of western Ireland, for example, are interpreted as frontal accretionary melange material associat ...
... et al., 1991). Frontal accretionary prisms, in contrast to underplated material, tend to be deformed but not substantially metamorphosed. The metasedimentary Westport Complex and South Connemara Group of western Ireland, for example, are interpreted as frontal accretionary melange material associat ...
Back-arc strain in subduction zones: Statistical observations versus
... initiated by imposing a weak dipping plate made of oceanic crust forming the interplate interface until 55 km depth, with a 30° dip angle (Figure 3). The oceanic crust strength is assumed to be very low with respect to the mantle stiffness (section 2.3). At convergence start, deformation localizes a ...
... initiated by imposing a weak dipping plate made of oceanic crust forming the interplate interface until 55 km depth, with a 30° dip angle (Figure 3). The oceanic crust strength is assumed to be very low with respect to the mantle stiffness (section 2.3). At convergence start, deformation localizes a ...
Arc-Continent collision in Taiwan: New marine observations and
... Arc-Continent collision is classically considered to be exemplified by the subduction of the continental margin of China under the Luzon island arc (Fig. 1). The transition from oceanic to continental subduction along the Manila Trench occurs near 22°N (Reed et al., 1992), but the impact on deformat ...
... Arc-Continent collision is classically considered to be exemplified by the subduction of the continental margin of China under the Luzon island arc (Fig. 1). The transition from oceanic to continental subduction along the Manila Trench occurs near 22°N (Reed et al., 1992), but the impact on deformat ...
Sediment Deposition Supports Seafloor Spreading
... organisms. Common 1500 m types include nannofossils, foraminifers, and diatoms. When microfossils are the major component of basement the sediment, then that sediment can be called an ooze. The sediment layer can be up to 2000 meters thick! Below the sediment is a layer of igneous rock, basalt, also ...
... organisms. Common 1500 m types include nannofossils, foraminifers, and diatoms. When microfossils are the major component of basement the sediment, then that sediment can be called an ooze. The sediment layer can be up to 2000 meters thick! Below the sediment is a layer of igneous rock, basalt, also ...
Methods for thermochemical convection in Earth`s mantle with force
... Department of Geological Science, University of Michigan, 2534 C.C. Little Building, Ann Arbor, Michigan 481091005, USA ([email protected]) ...
... Department of Geological Science, University of Michigan, 2534 C.C. Little Building, Ann Arbor, Michigan 481091005, USA ([email protected]) ...
Multiagent simulation of evolutive plate tectonics applied to the
... model plate tectonics must be expressed without directly solving differential equations of conservation, and (2) plate boundaries must be mobile to permit plate creation and destruction. Four types of agents interact in a 2D-cylindrical planet: convection cells, lithospheric plates, continents, and ...
... model plate tectonics must be expressed without directly solving differential equations of conservation, and (2) plate boundaries must be mobile to permit plate creation and destruction. Four types of agents interact in a 2D-cylindrical planet: convection cells, lithospheric plates, continents, and ...
e@ntlr rnrrul ll ng €dJuJeortttt ornr
... Just as a midoceanic rise crest is the descends into the mantle. morphologic signature of a fully developed divergent plate juncture, an developed conarc-crench system is the morphologic signature of a fully vergent plate juncture. The trench marks the subduction zone where magmatic arc, which may T ...
... Just as a midoceanic rise crest is the descends into the mantle. morphologic signature of a fully developed divergent plate juncture, an developed conarc-crench system is the morphologic signature of a fully vergent plate juncture. The trench marks the subduction zone where magmatic arc, which may T ...
Unit 1 Searching for Evidence
... high regions and find out what this other material is, you will examine block diagrams of the areas. Turn on the Block Diagrams theme. Activate the Block Diagrams theme. Using the Hot Link tool , click the profile lines crossing Greenland, Antarctica, and any other high regions you identified above, ...
... high regions and find out what this other material is, you will examine block diagrams of the areas. Turn on the Block Diagrams theme. Activate the Block Diagrams theme. Using the Hot Link tool , click the profile lines crossing Greenland, Antarctica, and any other high regions you identified above, ...
Sediments Are Historical Records of Ocean
... – Are often found in the form of nodules containing manganese and iron oxides – Evaporites are salts that precipitate as evaporation occurs and ...
... – Are often found in the form of nodules containing manganese and iron oxides – Evaporites are salts that precipitate as evaporation occurs and ...
Plate Tectonics
... valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle. – The oceanic crust bends downward into the mantle • Subduction – process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle. – Occurs at a convergent plate boundary ...
... valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle. – The oceanic crust bends downward into the mantle • Subduction – process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle. – Occurs at a convergent plate boundary ...
Antarctica Plate Motion - Indian National Science Academy
... We have analysed GPS measurements of site motion from fifty sites in the Antarctica, including the one set up by us at Maitri. The Maitri site exhibits a predominantly northward velocity of ~8 mm/year. Elsewhere on the Antarctica plate the site velocity estimates vary from 4 to 20 mm/year and exhibi ...
... We have analysed GPS measurements of site motion from fifty sites in the Antarctica, including the one set up by us at Maitri. The Maitri site exhibits a predominantly northward velocity of ~8 mm/year. Elsewhere on the Antarctica plate the site velocity estimates vary from 4 to 20 mm/year and exhibi ...
Notes and Discussions RICHARD H. SILLITOE Institute de
... in the context of Cass' (1968) interpretation of the Troodos ophiolite complex as part of the ocean rise system in the Tethys Ocean. Noble (1970) explained the close spatial association of metal deposits and igneous rocks in the western United States by proposing that metals rose from the mantle alo ...
... in the context of Cass' (1968) interpretation of the Troodos ophiolite complex as part of the ocean rise system in the Tethys Ocean. Noble (1970) explained the close spatial association of metal deposits and igneous rocks in the western United States by proposing that metals rose from the mantle alo ...
Dynamics and Evolution of European Margins
... the recent growth of prodelta systems by integrating knowledge ranging from river-discharge and flood dynamics (magnitude, recurrence, offshore impact), to estimates of sediment-accumulation rates based on short-lived radionuclides and/or sedimentological analyses of sediment cores from delta plain ...
... the recent growth of prodelta systems by integrating knowledge ranging from river-discharge and flood dynamics (magnitude, recurrence, offshore impact), to estimates of sediment-accumulation rates based on short-lived radionuclides and/or sedimentological analyses of sediment cores from delta plain ...
The geodynamic setting of Tertiary-Quaternary
... instability are possible, with upwellings originating from boundary layers in the Earth’s mantle such as the 650 km discontinuity or the core-mantle boundary. A variety of “evidence” has been used to argue for the existence of lower mantle plumes including teleseismic tomography, Sr-Nd-Pb-He isotope ...
... instability are possible, with upwellings originating from boundary layers in the Earth’s mantle such as the 650 km discontinuity or the core-mantle boundary. A variety of “evidence” has been used to argue for the existence of lower mantle plumes including teleseismic tomography, Sr-Nd-Pb-He isotope ...
Contraction of northeastern Japan: evidence from horizontal
... strain rates are smaller than the typical values in Japan by an order of magnitude in this region (Fujii et al, 1985). Accordingly, the movement of Kashima, to some extent, can be regarded to represent the east-west contraction rate of the arc. Such a contraction rate can be estimated as the spatial ...
... strain rates are smaller than the typical values in Japan by an order of magnitude in this region (Fujii et al, 1985). Accordingly, the movement of Kashima, to some extent, can be regarded to represent the east-west contraction rate of the arc. Such a contraction rate can be estimated as the spatial ...
OMAN: an obduction
... to distal turbidites were deposited in the Hawasina (Tethys) basin. Turbidite facies changes reflect fluctuations of the oceanic environment (radiolaritic cherts below the CCD in the Middle Trias) and oscillations of the sea level (siliciclastic turbidites under lower sea level: the Rhetian-Early Li ...
... to distal turbidites were deposited in the Hawasina (Tethys) basin. Turbidite facies changes reflect fluctuations of the oceanic environment (radiolaritic cherts below the CCD in the Middle Trias) and oscillations of the sea level (siliciclastic turbidites under lower sea level: the Rhetian-Early Li ...
Collision tectonics of the Mediterranean region
... and the compressional tectonics induced by the convergence between Eurasia and Afro-Arabia. Earlier collisional events caused the formation of thick orogenic crust, high-standing plateaus, and heterogeneous mantle, and resulted in slab break-offs that were collectively crucial for the onset of postc ...
... and the compressional tectonics induced by the convergence between Eurasia and Afro-Arabia. Earlier collisional events caused the formation of thick orogenic crust, high-standing plateaus, and heterogeneous mantle, and resulted in slab break-offs that were collectively crucial for the onset of postc ...
Plate Tectonics Review with Answers Rich Text
... 11. Plates slide past one another at ____. a. subduction zones b. transform boundaries ...
... 11. Plates slide past one another at ____. a. subduction zones b. transform boundaries ...
Scholarly Interest Report
... unresolved questions, using the Cascade volcanic arc as a natural laboratory. The prevailing model for arc magmatism involves mantle melting in response to additions of fluids produced by dehydration of subducting (underthrusting) plates of oceanic lithosphere. However, because the Cascade arc is as ...
... unresolved questions, using the Cascade volcanic arc as a natural laboratory. The prevailing model for arc magmatism involves mantle melting in response to additions of fluids produced by dehydration of subducting (underthrusting) plates of oceanic lithosphere. However, because the Cascade arc is as ...
Di}erential rotation of lithosphere and mantle and the driving forces
... been depicted as stationary or as showing only a small lag relative to the rotation axis reference "Knopo} and Leeds\ 0861^ Lliboutry\ 0863#[ The drag forces of 1 to 09×0908 N estimated in Table 0 for Africa " for Du −0 cm yr−0^ Knopo} and Leeds\ 0861# are in good agreement with the estimates of Ch ...
... been depicted as stationary or as showing only a small lag relative to the rotation axis reference "Knopo} and Leeds\ 0861^ Lliboutry\ 0863#[ The drag forces of 1 to 09×0908 N estimated in Table 0 for Africa " for Du −0 cm yr−0^ Knopo} and Leeds\ 0861# are in good agreement with the estimates of Ch ...
Isotopic Evolucon of the Earth (II)
... The shallow upper mantle which melts to form MORB at MORs cannot be representa-ve of the whole mantle The deeper mantle must be less depleted in incompa-ble trace elements, and have higher 87Sr/86Sr, lower 143Nd/144Nd than upper mantle ...
... The shallow upper mantle which melts to form MORB at MORs cannot be representa-ve of the whole mantle The deeper mantle must be less depleted in incompa-ble trace elements, and have higher 87Sr/86Sr, lower 143Nd/144Nd than upper mantle ...
Sediment Deposition Supports Seafloor Spreading
... organisms. Common 1500 m types include nannofossils, foraminifers, and diatoms. When microfossils are the major component of basement the sediment, then that sediment can be called an ooze. The sediment layer can be up to 2000 meters thick! Below the sediment is a layer of igneous rock, basalt, also ...
... organisms. Common 1500 m types include nannofossils, foraminifers, and diatoms. When microfossils are the major component of basement the sediment, then that sediment can be called an ooze. The sediment layer can be up to 2000 meters thick! Below the sediment is a layer of igneous rock, basalt, also ...
Subduction zone evolution and deep slab structure
... the independent motion of five microplates (Adria, Iberia, Alcapia, and Tiszia), which caused subduction zones consuming the Tethys Ocean – a Mesozoic Ocean preserved in the Alps. This subduction of the Alpine Tethys since Late Cretaceous caused a very complex plate-boundaryreorganization between se ...
... the independent motion of five microplates (Adria, Iberia, Alcapia, and Tiszia), which caused subduction zones consuming the Tethys Ocean – a Mesozoic Ocean preserved in the Alps. This subduction of the Alpine Tethys since Late Cretaceous caused a very complex plate-boundaryreorganization between se ...
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.