Mantle hydration and Cl-rich fluids in the subduction forearc
... coldest subduction zones because the warmer the subduction zone, the higher the amount of water released by dehydration of hydrothermally altered oceanic lithosphere. Interpretation of seismic data from petrophysical constrain is limited by complex effects due to anisotropy that needs to be assessed ...
... coldest subduction zones because the warmer the subduction zone, the higher the amount of water released by dehydration of hydrothermally altered oceanic lithosphere. Interpretation of seismic data from petrophysical constrain is limited by complex effects due to anisotropy that needs to be assessed ...
Magma Genesis and Mantle Dynamics at the Harrat Ash
... asthenosphere and from a plume component. In addition, some lavas have been affected by crustal contamination. This effect is most prominent in evolved lavas older than 3.5 Ma, which assimilated 3040% of crustal material. In general, the periodicity of volcanism in conjunction with temporal changes ...
... asthenosphere and from a plume component. In addition, some lavas have been affected by crustal contamination. This effect is most prominent in evolved lavas older than 3.5 Ma, which assimilated 3040% of crustal material. In general, the periodicity of volcanism in conjunction with temporal changes ...
Analogue modelling of continental collision: Influence of plate
... of the ductile layers decreases exponentially (Ranalli, 1995, 1997). Consequently, temperature driven time–space variability of rheology during shortening cannot be accounted for, and we assume an initial homogenous plate rheology which did not suffer pre-extensional thinning or earlier thickening a ...
... of the ductile layers decreases exponentially (Ranalli, 1995, 1997). Consequently, temperature driven time–space variability of rheology during shortening cannot be accounted for, and we assume an initial homogenous plate rheology which did not suffer pre-extensional thinning or earlier thickening a ...
Alteration of the subducting oceanic lithosphere at the southern
... penetrating deep into the uppermost mantle [e.g., Peacock, 2001; Ranero et al., 2003]. Moreover, new crustal cracks and fissures are caused by bending-related faulting seaward of the trench axis, modifying the structure of the crust. Therefore bending-related faulting plays a crucial role for the al ...
... penetrating deep into the uppermost mantle [e.g., Peacock, 2001; Ranero et al., 2003]. Moreover, new crustal cracks and fissures are caused by bending-related faulting seaward of the trench axis, modifying the structure of the crust. Therefore bending-related faulting plays a crucial role for the al ...
Upper Mantle Tomographic Vp and Vs Images of the Rocky
... travel-time residuals for the S-waves. Typical choices include the SH component, the average fast or slow anisotropy axis detected from shear wave splitting, or the maximum particle motion direction. The SH component waveform is least contaminated by the scattering from near station structures, and ...
... travel-time residuals for the S-waves. Typical choices include the SH component, the average fast or slow anisotropy axis detected from shear wave splitting, or the maximum particle motion direction. The SH component waveform is least contaminated by the scattering from near station structures, and ...
Igneous Rock Associations 8. Arc Magmatism II: Geo
... enstatite. Equilibrium crystallization or fractionation of these minerals drives the residual liquid composition away initially from olivine (X to T) until it reaches and then descends the olivineenstatite curve (T to P). Along pathway X to P, the magma becomes enriched in other components, includin ...
... enstatite. Equilibrium crystallization or fractionation of these minerals drives the residual liquid composition away initially from olivine (X to T) until it reaches and then descends the olivineenstatite curve (T to P). Along pathway X to P, the magma becomes enriched in other components, includin ...
A review of observations and models of dynamic
... long-wavelength inferred vertical motions have been attributed to dynamic topography. An important consequence of dynamic topography is that long-term global sea-level change cannot be estimated at a single passive margin. As a case study, we compare the results of three published models and of our ...
... long-wavelength inferred vertical motions have been attributed to dynamic topography. An important consequence of dynamic topography is that long-term global sea-level change cannot be estimated at a single passive margin. As a case study, we compare the results of three published models and of our ...
letters - Noble Gas Geochemistry Lab
... has been long debated, we show that the source of this signature beneath the western Gakkel ridge was subcontinental lithospheric mantle that delaminated and became integrated into the convecting Arctic asthenosphere. This occurred as North Atlantic mantle propagated north into the Arctic during the ...
... has been long debated, we show that the source of this signature beneath the western Gakkel ridge was subcontinental lithospheric mantle that delaminated and became integrated into the convecting Arctic asthenosphere. This occurred as North Atlantic mantle propagated north into the Arctic during the ...
How Mantle Slabs Drive Plate Tectonics
... zones), while overriding plates in the slab pull model move at the right speed but in the wrong direction (away from subduction zones). This suggests that a combination of the two models should cause both subducting and overriding plates to move in the correct direction at the correct speed. For sim ...
... zones), while overriding plates in the slab pull model move at the right speed but in the wrong direction (away from subduction zones). This suggests that a combination of the two models should cause both subducting and overriding plates to move in the correct direction at the correct speed. For sim ...
1 Origin and geodynamic relationships of the Late Miocene to
... In the Pannonian Basin, eruption of alkali basaltic magmas started in the westernmost margin, where two outcrops are known, at Pauliberg and at Oberpullendorf in Burgenland ...
... In the Pannonian Basin, eruption of alkali basaltic magmas started in the westernmost margin, where two outcrops are known, at Pauliberg and at Oberpullendorf in Burgenland ...
Magma genesis, plate tectonics, and chemical
... also provide clues about the nature of the source material at (volume 25, numbers 2, 3, 5, and 6, 1987). Volcanoes have played a significant role in the development depth. The theme common to the different parts of this review of geology sinceAbraham Werner at the beginning of the last relates to th ...
... also provide clues about the nature of the source material at (volume 25, numbers 2, 3, 5, and 6, 1987). Volcanoes have played a significant role in the development depth. The theme common to the different parts of this review of geology sinceAbraham Werner at the beginning of the last relates to th ...
Shervais, J.W., Significance of Subduction
... with material from both sides of the convergence zone sinking back into the hot asthenosphere symmetrically (figure 1). Modern, asymmetric convergence, which is driven by the sinking of cold lithospheric plates, is not observed (Zhong et al., 2000; Bercovici, 2003), and may not have occurred in the ...
... with material from both sides of the convergence zone sinking back into the hot asthenosphere symmetrically (figure 1). Modern, asymmetric convergence, which is driven by the sinking of cold lithospheric plates, is not observed (Zhong et al., 2000; Bercovici, 2003), and may not have occurred in the ...
Circulation of the North Atlantic Ocean from altimetry and the Gravity
... synthesize the geoid undulation on a geodetic 20 grid, consistent with the mean sea surface height. The geoid undulation was computed using the geoid synthesis program by Smith [1998] for a reference ellipsoid consistent with the CLS01 mean sea surface. For reference, the CLS01 mean sea surface prod ...
... synthesize the geoid undulation on a geodetic 20 grid, consistent with the mean sea surface height. The geoid undulation was computed using the geoid synthesis program by Smith [1998] for a reference ellipsoid consistent with the CLS01 mean sea surface. For reference, the CLS01 mean sea surface prod ...
Dynamical geochemistry of the mantle
... with smaller proportions of eclogite and pyroxenite (Ringwood, 1975; Hofmann, 1997). With the advent of plate tectonics a straightforward explanation for this became evident: a subducting plate is a layered structure, with mafic oceanic crust on top and an ultramafic (peridotite) mantle section unde ...
... with smaller proportions of eclogite and pyroxenite (Ringwood, 1975; Hofmann, 1997). With the advent of plate tectonics a straightforward explanation for this became evident: a subducting plate is a layered structure, with mafic oceanic crust on top and an ultramafic (peridotite) mantle section unde ...
Crust–mantle boundaries in the Taiwan–Luzon arc
... weighting of 1.5, 1.0, 0.5 and 0.125, respectively, for calculating travel time fit. In total, 52 stations with more than 2000 P-wave travel times per station were used (Fig. 3 and Table 1). Stations that do not meet this requirement are usually at the periphery of the network (Fig. 3). A genetic alg ...
... weighting of 1.5, 1.0, 0.5 and 0.125, respectively, for calculating travel time fit. In total, 52 stations with more than 2000 P-wave travel times per station were used (Fig. 3 and Table 1). Stations that do not meet this requirement are usually at the periphery of the network (Fig. 3). A genetic alg ...
Pulsing of a focused mantle plume: Evidence from the distribution of
... preferential channeling of plume material [e.g., Morgan, 1978; Schilling, 1985, 1991] to the nearby spreading center responsible for this younger seafloor. [5] If the previously proposed relationship between the Foundation plume and older seamounts in the Austral Island region [McNutt et al., 1997; ...
... preferential channeling of plume material [e.g., Morgan, 1978; Schilling, 1985, 1991] to the nearby spreading center responsible for this younger seafloor. [5] If the previously proposed relationship between the Foundation plume and older seamounts in the Austral Island region [McNutt et al., 1997; ...
Geology of Greenland Survey Bulletin 177, 89-95
... voluminous ocean floor basalts with MgO contents of less than 12% were produced by passive upwelling from mantle sources with ‘normal’ temperatures around 1300°C, located under mid-ocean ridges. In other words, the high mantle temperatures related to komatiite production need not have been character ...
... voluminous ocean floor basalts with MgO contents of less than 12% were produced by passive upwelling from mantle sources with ‘normal’ temperatures around 1300°C, located under mid-ocean ridges. In other words, the high mantle temperatures related to komatiite production need not have been character ...
Finite source modelling of magmatic unrest in Socorro, New Mexico
... formation of the Socorro sill by a steady-state melt injection over the last several tens of thousands of years (Schlue et al. 1996). However, simple thermal arguments indicate that such a scenario is unlikely, as the minimum freezing rate of a 100 m thick (or thinner) sheet intrusion is significant ...
... formation of the Socorro sill by a steady-state melt injection over the last several tens of thousands of years (Schlue et al. 1996). However, simple thermal arguments indicate that such a scenario is unlikely, as the minimum freezing rate of a 100 m thick (or thinner) sheet intrusion is significant ...
A2 Course Study Guide
... chloride ions are situated as if they were at the corners of cubes. Each sodium ion is surrounded by six chlorine ions and each chlorine ion is surrounded by six sodium ions. Minerals containing silicon combined with oxygen are silicate minerals and have a more complex crystal structure. In silicate ...
... chloride ions are situated as if they were at the corners of cubes. Each sodium ion is surrounded by six chlorine ions and each chlorine ion is surrounded by six sodium ions. Minerals containing silicon combined with oxygen are silicate minerals and have a more complex crystal structure. In silicate ...
imaging the upper mantle beneath turkey and surrounding regions
... This study includes two interdependent sections. The first section presents an analysis of Pn travel times to determine Pn velocity, Pn anisotropy and crustal thickness variations beneath Turkey and surroundings. Between 1999 and 2010, more than 50 000 Pn arrivals are compiled from 700 regional eart ...
... This study includes two interdependent sections. The first section presents an analysis of Pn travel times to determine Pn velocity, Pn anisotropy and crustal thickness variations beneath Turkey and surroundings. Between 1999 and 2010, more than 50 000 Pn arrivals are compiled from 700 regional eart ...
The gravity and topography of the terrestrial planets
... in our understanding and knowledge of the gravity and topography fields of the terrestrial planets. These advances are intimately related to the acquisition of radio tracking data from orbiting spacecraft (which can be used to invert for the gravity field), as well as the collection of data from orb ...
... in our understanding and knowledge of the gravity and topography fields of the terrestrial planets. These advances are intimately related to the acquisition of radio tracking data from orbiting spacecraft (which can be used to invert for the gravity field), as well as the collection of data from orb ...
Supercontinents, mantle dynamics and plate
... The periodic assembly and dispersal of supercontinents through the history of the Earth had considerable impact on mantle dynamics and surface processes. Here we synthesize some of the conceptual models on supercontinent amalgamation and disruption and combine it with recent information from numeric ...
... The periodic assembly and dispersal of supercontinents through the history of the Earth had considerable impact on mantle dynamics and surface processes. Here we synthesize some of the conceptual models on supercontinent amalgamation and disruption and combine it with recent information from numeric ...
10. Stress and stress release in the lithosphere
... supply. The underground storage of gas in caverns and abandoned gas reservoirs requires a good knowledge about geomechanical stresses and is an important contribution to stable energy supply. For the efficient use of geothermal energy and for EGS systems at depth geomechanics is an important issue i ...
... supply. The underground storage of gas in caverns and abandoned gas reservoirs requires a good knowledge about geomechanical stresses and is an important contribution to stable energy supply. For the efficient use of geothermal energy and for EGS systems at depth geomechanics is an important issue i ...
Global scale models of the mantle flow field predicted by synthetic
... One way to investigate the method of using seismic observations to derive global-scale 3D models of the mantle flow field is to run joint seismological and geodynamic inversions (e.g., Simmons et al., 2007). Here, we focus on a different approach and use a multidisciplinary technique developed in prev ...
... One way to investigate the method of using seismic observations to derive global-scale 3D models of the mantle flow field is to run joint seismological and geodynamic inversions (e.g., Simmons et al., 2007). Here, we focus on a different approach and use a multidisciplinary technique developed in prev ...
Seafloor Spreading Hypothesis
... mountains in the Pacific that he gave the name guyot. He puzzled at what could have formed mountains that appeared to be eroded at the top but were more than a mile beneath the sea surface. Hess also noticed trenches that were as much as 7 miles deep. Meanwhile, other scientists like Bruce Heezen di ...
... mountains in the Pacific that he gave the name guyot. He puzzled at what could have formed mountains that appeared to be eroded at the top but were more than a mile beneath the sea surface. Hess also noticed trenches that were as much as 7 miles deep. Meanwhile, other scientists like Bruce Heezen di ...
Post-glacial rebound
Post-glacial rebound (sometimes called continental rebound) is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period, through a process known as isostatic depression. Post-glacial rebound and isostatic depression are different parts of a process known as either glacial isostasy, glacial isostatic adjustment, or glacioisostasy. Glacioisostasy is the solid Earth deformation associated with changes in ice mass distribution. The most obvious and direct affects of post-glacial rebound are readily apparent in northern Europe (especially Scotland, Estonia, Latvia, Fennoscandia, and northern Denmark), Siberia, Canada, the Great Lakes of Canada and the United States, the coastal region of the US state of Maine, parts of Patagonia, and Antarctica. However, through processes known as ocean siphoning and continental levering, the effects of post-glacial rebound on sea-level are felt globally far from the locations of current and former ice sheets.