Eduard Suess` conception of the Alpine orogeny related to
... to which Suess himself contributed a substantial amount of research, supported his geological work and tectonic reasoning to some extent. Since the publication of „Die Entstehung der Alpen“, Physics of the Earth has made tremendous progress and geophysical data and models have become of fundamental ...
... to which Suess himself contributed a substantial amount of research, supported his geological work and tectonic reasoning to some extent. Since the publication of „Die Entstehung der Alpen“, Physics of the Earth has made tremendous progress and geophysical data and models have become of fundamental ...
Influence of convergent plate boundaries on upper mantle flow and
... [1] Shear-wave splitting observations in the region of the upper mantle enveloping subduction zones have been interpreted as showing extensive regions of trench-parallel flow, despite the difficulty of reconciling such behavior with a sound model based on the forces that drive mantle motion. To gain ...
... [1] Shear-wave splitting observations in the region of the upper mantle enveloping subduction zones have been interpreted as showing extensive regions of trench-parallel flow, despite the difficulty of reconciling such behavior with a sound model based on the forces that drive mantle motion. To gain ...
evidence from Th, Sr and Pb isotope data for Tonga
... suggest that geochemical variations in the lavas along the arc are linked to differences in the material being subducted beneath the arc. Lavas from the southern (Kermadec) segment of the arc have relatively radiogenic Pb isotope compositions, which reflects a contribution from subducted sediment. I ...
... suggest that geochemical variations in the lavas along the arc are linked to differences in the material being subducted beneath the arc. Lavas from the southern (Kermadec) segment of the arc have relatively radiogenic Pb isotope compositions, which reflects a contribution from subducted sediment. I ...
Tectonic fabric of the subcontinental lithosphere
... crustal depths (<35 km), almost all geoelectric strikes exhibit characteristic 90◦ rotations across terrane boundaries. This directional behavior is also observed, but to a lesser extent, for upper-mantle depths (>45 km), indicating that some major geological structures penetrate the Moho whereas ot ...
... crustal depths (<35 km), almost all geoelectric strikes exhibit characteristic 90◦ rotations across terrane boundaries. This directional behavior is also observed, but to a lesser extent, for upper-mantle depths (>45 km), indicating that some major geological structures penetrate the Moho whereas ot ...
Mid-ocean ridges
... whereas the upper parts must be variably depleted due to magma extraction at the ridge axis. The oceanic crust, comprising the upper 8-10 km of the lithosphere, also has its origins at the ridge axis due to the extrusion and intrusion of basaltic magma. It has a well layered layer structure (deduced ...
... whereas the upper parts must be variably depleted due to magma extraction at the ridge axis. The oceanic crust, comprising the upper 8-10 km of the lithosphere, also has its origins at the ridge axis due to the extrusion and intrusion of basaltic magma. It has a well layered layer structure (deduced ...
Seismic Observation Equipment
... An earthquake is a phenomenon in which a release of energy, caused by slippage at the boundaries of tectonic plates just below the earth’s crust, causes waves to travel along the ground, making it vibrate violently. The vibrations caused by earthquakes include longitudinal (or compression) waves (P- ...
... An earthquake is a phenomenon in which a release of energy, caused by slippage at the boundaries of tectonic plates just below the earth’s crust, causes waves to travel along the ground, making it vibrate violently. The vibrations caused by earthquakes include longitudinal (or compression) waves (P- ...
An ultraslow-spreading class of ocean ridge
... But this classification also does not take into account variations in crustal thickness with spreading rate. Although seismic crustal thickness shows little dependency on spreading rate down to 20 mm yr21, it then drops off rapidly (Fig. 1b). Models for buoyant and passive plate-driven mantle flow a ...
... But this classification also does not take into account variations in crustal thickness with spreading rate. Although seismic crustal thickness shows little dependency on spreading rate down to 20 mm yr21, it then drops off rapidly (Fig. 1b). Models for buoyant and passive plate-driven mantle flow a ...
An ultraslow-spreading class of ocean ridge
... But this classification also does not take into account variations in crustal thickness with spreading rate. Although seismic crustal thickness shows little dependency on spreading rate down to 20 mm yr21, it then drops off rapidly (Fig. 1b). Models for buoyant and passive plate-driven mantle flow a ...
... But this classification also does not take into account variations in crustal thickness with spreading rate. Although seismic crustal thickness shows little dependency on spreading rate down to 20 mm yr21, it then drops off rapidly (Fig. 1b). Models for buoyant and passive plate-driven mantle flow a ...
On the role of subducting oceanic plateaus in the development of
... possible mechanism to explain the occurrence of flat subduction and related absence of arc magmatism below Peru, Central Chile and at the Nankai Trough (Japan). Their extra compositional buoyancy could prohibit the slab from sinking into the mantle. With a numerical thermochemical convection model, ...
... possible mechanism to explain the occurrence of flat subduction and related absence of arc magmatism below Peru, Central Chile and at the Nankai Trough (Japan). Their extra compositional buoyancy could prohibit the slab from sinking into the mantle. With a numerical thermochemical convection model, ...
Relations between sedimentary basins and petroleum
... Paranà in Brazil, the Deccan Traps in India, or the Ontong-Java Plateau in the south-western Pacific (LIPs, Large Igneous Provinces). Their origin is not clear, either as regards the depth of their source or the dynamics of the process. There are also magmatic events which describe linear tracks ove ...
... Paranà in Brazil, the Deccan Traps in India, or the Ontong-Java Plateau in the south-western Pacific (LIPs, Large Igneous Provinces). Their origin is not clear, either as regards the depth of their source or the dynamics of the process. There are also magmatic events which describe linear tracks ove ...
Twin Hotspot Tracks and Ridge Jumps
... et al ; Barckhausen et al ) It has been demonstrated that the products of the hotspot volcanism covered a complex pattern of oceanic crust formed at three subsequently active symmetric spreading systems of different orientation The identified extinct spreading systems represent precur ...
... et al ; Barckhausen et al ) It has been demonstrated that the products of the hotspot volcanism covered a complex pattern of oceanic crust formed at three subsequently active symmetric spreading systems of different orientation The identified extinct spreading systems represent precur ...
Deep crustal fracture zones control fluid escape and the seismic
... Seismic activity and non-volcanic tremors are often associated with fluid circulation resulting from the dehydration of subducting plates. Tremors in the overriding continental crust of several subduction zones suggest fluid circulation at shallower depths, but potential fluid pathways are still poorly ...
... Seismic activity and non-volcanic tremors are often associated with fluid circulation resulting from the dehydration of subducting plates. Tremors in the overriding continental crust of several subduction zones suggest fluid circulation at shallower depths, but potential fluid pathways are still poorly ...
Mechanism and timing of Pb transport from subducted oceanic crust
... upper mantle. High 207Pb/204Pb ratios in many arc lavas relative to midocean ridge basalts are generally thought to result from addition of subducted sediment (e.g. Woodhead, 1989; Elliott et al., 1997; Ewart et al., 1998). Unfortunately, it is much more difficult to estimate the relative contributio ...
... upper mantle. High 207Pb/204Pb ratios in many arc lavas relative to midocean ridge basalts are generally thought to result from addition of subducted sediment (e.g. Woodhead, 1989; Elliott et al., 1997; Ewart et al., 1998). Unfortunately, it is much more difficult to estimate the relative contributio ...
A multiphase seismic investigation of the shallow subduction zone
... The seismic velocities and depths of the five layers are parametrized in terms of 2-D B-splines. The B-spline functions are expressed as a linear combination of B-spline basis functions (Powell 1991) and interpolate between knot points of specified layer depth to form surfaces approximating the laye ...
... The seismic velocities and depths of the five layers are parametrized in terms of 2-D B-splines. The B-spline functions are expressed as a linear combination of B-spline basis functions (Powell 1991) and interpolate between knot points of specified layer depth to form surfaces approximating the laye ...
A selfconsistent model of melting, magma migration and
... buoyancy of the liquid should cause it to migrate upward relative to the solid with ease. When considering the zc Ftot x,, ...
... buoyancy of the liquid should cause it to migrate upward relative to the solid with ease. When considering the zc Ftot x,, ...
4. Structure of the Peru Forearc from Multichannel Seismic
... landward slope. An apparent subducting graben is imaged at 1625 UTC (Plate 1). Preliminary depth conversions suggest that the upward bend in the oceanic crust reflector at about 1450 UTC is a velocity pullup caused by the overlying high-velocity continental crust (see Hussong and Wipperman, 1981). T ...
... landward slope. An apparent subducting graben is imaged at 1625 UTC (Plate 1). Preliminary depth conversions suggest that the upward bend in the oceanic crust reflector at about 1450 UTC is a velocity pullup caused by the overlying high-velocity continental crust (see Hussong and Wipperman, 1981). T ...
The link between the Moho depth of the NE Atlantic margin and
... continent, the magnetic field is only of limited use to analyze the deep structure of the margin, while it clearly helps to study crustal domains and top basement. Gravity and GOCE satellite data The thermal gradient between the oceanic and continental plate is also observable as a long wavelength t ...
... continent, the magnetic field is only of limited use to analyze the deep structure of the margin, while it clearly helps to study crustal domains and top basement. Gravity and GOCE satellite data The thermal gradient between the oceanic and continental plate is also observable as a long wavelength t ...
Isostasy, flexure, and dynamic topography
... Moucha and Forte, 2011; Becker et al., 2014). In this term, dynamic refers to moving mass anomalies unlike isostasy that refers to quasi-static mass anomalies. Note, however, that whether or not lithospheric-scale processes, such as small-scale convection in the thermal boundary layer and cooling of ...
... Moucha and Forte, 2011; Becker et al., 2014). In this term, dynamic refers to moving mass anomalies unlike isostasy that refers to quasi-static mass anomalies. Note, however, that whether or not lithospheric-scale processes, such as small-scale convection in the thermal boundary layer and cooling of ...
Melt Generation at Very Slow-Spreading Oceanic Ridges
... the degree of serpentinization. So if Hess were correct, one would expect to see large variability in layer 3 seismic velocities. But it is not inconsistent with Cannat’s (1993, 1996) more recent suggestions, based on the recovery from the sea floor of serpentinized peridotites, often intruded by ga ...
... the degree of serpentinization. So if Hess were correct, one would expect to see large variability in layer 3 seismic velocities. But it is not inconsistent with Cannat’s (1993, 1996) more recent suggestions, based on the recovery from the sea floor of serpentinized peridotites, often intruded by ga ...
Deformation in the asthenospheric mantle beneath the Carpathian
... groups could be distinguished. The first group might represent the new juvenile part of the lithosphere which has been accreted from the asthenosphere since the end of the extension in the thermal relaxation stage [Kovács et al., 2012]. Since the focus of the present study is on the upper mantle, we ...
... groups could be distinguished. The first group might represent the new juvenile part of the lithosphere which has been accreted from the asthenosphere since the end of the extension in the thermal relaxation stage [Kovács et al., 2012]. Since the focus of the present study is on the upper mantle, we ...
physical, chemical, and chronological characteristics of
... are seen under tectonically active continental regions, such as the Basin and Range, but available evidence indicates that in these continental areas the mantle low-velocity zone begins immediately beneath the Moho, with a high-velocity ‘‘lid’’ similar to that seen in ocean basins notably absent. Lo ...
... are seen under tectonically active continental regions, such as the Basin and Range, but available evidence indicates that in these continental areas the mantle low-velocity zone begins immediately beneath the Moho, with a high-velocity ‘‘lid’’ similar to that seen in ocean basins notably absent. Lo ...
Mantle plume
A mantle plume is a mechanism proposed in 1971 to explain volcanic regions of the earth that were not thought to be explicable by the then-new theory of plate tectonics. Some such volcanic regions lie far from tectonic plate boundaries, for example, Hawaii. Others represent unusually large-volume volcanism, whether on plate boundaries, e.g. Iceland, or basalt floods such as the Deccan or Siberian traps.A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. The currently active volcanic centers are known as ""hot spots"". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.The hypothesis of mantle plumes from depth is not universally accepted as explaining all such volcanism. It has required progressive hypothesis-elaboration leading to variant propositions such as mini-plumes and pulsing plumes. Another hypothesis for unusual volcanic regions is the ""Plate model"". This proposes shallower, passive leakage of magma from the mantle onto the Earth's surface where extension of the lithosphere permits it, attributing most volcanism to plate tectonic processes, with volcanoes far from plate boundaries resulting from intraplate extension.