2014-Wannamaker-Casc.. - University of Alberta
... overprint southward into Oregon and northeastern California [Hildreth, 2007; Schmidt et al., 2008]. The physicochemical states at depth that represent the driving factors behind surface observations have been interpreted to date largely on the basis of seismology, geodesy, structural geology, and vo ...
... overprint southward into Oregon and northeastern California [Hildreth, 2007; Schmidt et al., 2008]. The physicochemical states at depth that represent the driving factors behind surface observations have been interpreted to date largely on the basis of seismology, geodesy, structural geology, and vo ...
- Wiley Online Library
... overprint southward into Oregon and northeastern California [Hildreth, 2007; Schmidt et al., 2008]. The physicochemical states at depth that represent the driving factors behind surface observations have been interpreted to date largely on the basis of seismology, geodesy, structural geology, and vo ...
... overprint southward into Oregon and northeastern California [Hildreth, 2007; Schmidt et al., 2008]. The physicochemical states at depth that represent the driving factors behind surface observations have been interpreted to date largely on the basis of seismology, geodesy, structural geology, and vo ...
The Tectonic Framework of the Sumatran Subduction Zone
... deep trench, and the subducting oceanic plate. Hamilton (1979) suggests that Sumatra was rifted from the northern edge of Australia (north of New Guinea) during the Triassic to early Jurassic (∼200–250 Ma). Sumatra would have been a stable continental margin from then until subduction began in the C ...
... deep trench, and the subducting oceanic plate. Hamilton (1979) suggests that Sumatra was rifted from the northern edge of Australia (north of New Guinea) during the Triassic to early Jurassic (∼200–250 Ma). Sumatra would have been a stable continental margin from then until subduction began in the C ...
Ringwood Phase transformations and their bearing on the
... petrological differentia~on of pyrolite at mid-ocean spreading centres to form new oceanic lithosphere. The MORB basaltic crust is underlain by a layer of harzburgite. During subduction, these lithologies each respond to sequential phase transformations in a different manner, so that at any given de ...
... petrological differentia~on of pyrolite at mid-ocean spreading centres to form new oceanic lithosphere. The MORB basaltic crust is underlain by a layer of harzburgite. During subduction, these lithologies each respond to sequential phase transformations in a different manner, so that at any given de ...
Subduction of young oceanic plates: A numerical study with
... (Figure 2b). As the trench retreats the melt‐bearing asthenosphere rises forming an intra‐arc spreading center leading to splitting of the arc and development of a remnant arc located trenchward and a back‐arc basin (∼10 Myr; Figure 2c). The formation of a spreading center accelerates trench retreat ...
... (Figure 2b). As the trench retreats the melt‐bearing asthenosphere rises forming an intra‐arc spreading center leading to splitting of the arc and development of a remnant arc located trenchward and a back‐arc basin (∼10 Myr; Figure 2c). The formation of a spreading center accelerates trench retreat ...
cyclicity in cordilleran orogenic systems
... and mantle lithosphere (Fig. 3d). High-flux events are clearly synchronous with root development; systems that produce thick batholiths, in some cases >30 km thick43, are almost certain to develop a root that is denser than the underlying mantle15. Consequently, delamination of the lower crust and ...
... and mantle lithosphere (Fig. 3d). High-flux events are clearly synchronous with root development; systems that produce thick batholiths, in some cases >30 km thick43, are almost certain to develop a root that is denser than the underlying mantle15. Consequently, delamination of the lower crust and ...
Metamorphic chemical geodynamics of subduction zones
... 2003; Tsujimori et al., 2006; Ernst, 2006), and a number of UHP suites contain oceanic rocks that were first deeply subducted, then exhumed relatively rapidly during later continent–continent collisions (e.g., Western Alps; Ernst, 2006). Their mineral assemblages, textures, and geochemistry preserve ...
... 2003; Tsujimori et al., 2006; Ernst, 2006), and a number of UHP suites contain oceanic rocks that were first deeply subducted, then exhumed relatively rapidly during later continent–continent collisions (e.g., Western Alps; Ernst, 2006). Their mineral assemblages, textures, and geochemistry preserve ...
Bebout Metamorphic chemical geodynamics of subduction zones
... 2003; Tsujimori et al., 2006; Ernst, 2006), and a number of UHP suites contain oceanic rocks that were first deeply subducted, then exhumed relatively rapidly during later continent–continent collisions (e.g., Western Alps; Ernst, 2006). Their mineral assemblages, textures, and geochemistry preserve ...
... 2003; Tsujimori et al., 2006; Ernst, 2006), and a number of UHP suites contain oceanic rocks that were first deeply subducted, then exhumed relatively rapidly during later continent–continent collisions (e.g., Western Alps; Ernst, 2006). Their mineral assemblages, textures, and geochemistry preserve ...
Review of the Lithium Isotope System as a Geochemical Tracer
... radiogenic isotopic ratios used to monitor chemical weathering (Huh et al., 1998). There is thus promise in using the evolution of the Li isotope ratio of seawater to assess past changes in the intensity of continental weathering (Raymo et al., 1988). In other words, it might be anticipated that a c ...
... radiogenic isotopic ratios used to monitor chemical weathering (Huh et al., 1998). There is thus promise in using the evolution of the Li isotope ratio of seawater to assess past changes in the intensity of continental weathering (Raymo et al., 1988). In other words, it might be anticipated that a c ...
Ancient recycled mantle lithosphere in the Hawaiian plume: Osmium
... composition of the plume has always been inferred from the compositions of the erupted lavas. It has been suggested that recycled (i.e. previously subducted) basaltic oceanic crust (with or without sediments) is part of this plume and responsible for the enriched isotopic compositions of the Hawaiia ...
... composition of the plume has always been inferred from the compositions of the erupted lavas. It has been suggested that recycled (i.e. previously subducted) basaltic oceanic crust (with or without sediments) is part of this plume and responsible for the enriched isotopic compositions of the Hawaiia ...
PDF (Chapter 10. Isotopes)
... relative to the shallow mantle. It may be that basalts originate primarily from only one of these reservoirs and that the trace-element and isotopic diversity is acquired when they traverse the shallow mantle on their way to the surface. The crust is extremely enriched in many of the socalled incomp ...
... relative to the shallow mantle. It may be that basalts originate primarily from only one of these reservoirs and that the trace-element and isotopic diversity is acquired when they traverse the shallow mantle on their way to the surface. The crust is extremely enriched in many of the socalled incomp ...
Major and trace analysis of basaltic glasses by laser-ablation ICP-MS
... above 10, the hampering to the slab sinking speed in the upper mantle is due to the barrier formed by the upper-lower mantle discontinuity [Capitanio et al., 2007; Christensen and Yuen, 1984; Zhong and Gurnis, 1995b], and considering that slabs in the lower mantle are likely less viscous and occupy ...
... above 10, the hampering to the slab sinking speed in the upper mantle is due to the barrier formed by the upper-lower mantle discontinuity [Capitanio et al., 2007; Christensen and Yuen, 1984; Zhong and Gurnis, 1995b], and considering that slabs in the lower mantle are likely less viscous and occupy ...
Preliminary analysis of the Knipovich Ridge segmentation: in£uence
... Bathymetry, gravity and deep-tow sonar image data are used to define the segmentation of a 400 km long portion of the ultraslow-spreading Knipovich Ridge in the Norwegian^Greenland Sea, Northeast Atlantic Ocean. Discrete volcanic centers marked by large volcanic constructions and accompanying short ...
... Bathymetry, gravity and deep-tow sonar image data are used to define the segmentation of a 400 km long portion of the ultraslow-spreading Knipovich Ridge in the Norwegian^Greenland Sea, Northeast Atlantic Ocean. Discrete volcanic centers marked by large volcanic constructions and accompanying short ...
LITHOSPHERIC STRUCTURE OF THE ARABIAN PLATE AND
... the Dead Sea fault system and in the northern portion of the Arabian plate (south of the Bitlis suture)., We observed Sn blockage across some segments of the Red Sea. These regions of high Sn attenuation have anomalously hot and possibly thin lithospheric mantle (i.e., mantle lid). Consistent with o ...
... the Dead Sea fault system and in the northern portion of the Arabian plate (south of the Bitlis suture)., We observed Sn blockage across some segments of the Red Sea. These regions of high Sn attenuation have anomalously hot and possibly thin lithospheric mantle (i.e., mantle lid). Consistent with o ...
Kohlstedt answers PDF
... Some breakthroughs in technology are needed to extend our experiments in this area. The primary need is for sensors (chemical and mechanical) that operate at high temperatures and high pressures. Most instrumentation gets crushed or burned up under out P,T conditions. Question 1: Could the propertie ...
... Some breakthroughs in technology are needed to extend our experiments in this area. The primary need is for sensors (chemical and mechanical) that operate at high temperatures and high pressures. Most instrumentation gets crushed or burned up under out P,T conditions. Question 1: Could the propertie ...
Mantle Mixing - Earth and Environmental Sciences
... Reykjanes ridge to show that this defines a mixing line where K=1 (Figure 2). In the limiting case where the Pb concentration of the plume is the same as that of DMM (Pb~0.05 ppm) it follows that Heplume=HeDMM. The 3He/4He of the plume endmember is 4 times higher than the DMM component and consequen ...
... Reykjanes ridge to show that this defines a mixing line where K=1 (Figure 2). In the limiting case where the Pb concentration of the plume is the same as that of DMM (Pb~0.05 ppm) it follows that Heplume=HeDMM. The 3He/4He of the plume endmember is 4 times higher than the DMM component and consequen ...
Electrical conductivity as a constraint on lower mantle thermo
... for ionic conduction E a > 1 eV, implying (Eq. (1)) that ionic conductivity is much smaller than small polaron. Second, because it strongly depends on the water content (Yoshino et al., 2009), proton conduction may be much less efficient in the lower mantle than in the upper mantle, since the former i ...
... for ionic conduction E a > 1 eV, implying (Eq. (1)) that ionic conductivity is much smaller than small polaron. Second, because it strongly depends on the water content (Yoshino et al., 2009), proton conduction may be much less efficient in the lower mantle than in the upper mantle, since the former i ...
A trace element perspective on the source of ocean island basalts
... We analyze the first-order observations, basic concepts and explicit/implicit assumptions built into the three major hypotheses for the enriched component(s) in the source of ocean island basalts (OIB) in terms of incompatible trace elements: (1) subducted ocean crust (SOC), (2) subducted continenta ...
... We analyze the first-order observations, basic concepts and explicit/implicit assumptions built into the three major hypotheses for the enriched component(s) in the source of ocean island basalts (OIB) in terms of incompatible trace elements: (1) subducted ocean crust (SOC), (2) subducted continenta ...
- White Rose Research Online
... We used a crustal cross section based on a 2-D gravity model to estimate the extension of the continental crust across the Laptev Rift System. The 2-D gravity profile, supported by published seismic data [Drachev et al., 1998; Franke et al., 2001], constrained the limit of undeformed crust and provid ...
... We used a crustal cross section based on a 2-D gravity model to estimate the extension of the continental crust across the Laptev Rift System. The 2-D gravity profile, supported by published seismic data [Drachev et al., 1998; Franke et al., 2001], constrained the limit of undeformed crust and provid ...
TROPICS Continent-Building in Costa Rica
... note, somewhat incidentally, that standard subduction is presently taking place only in the northern half of Costa Rica. In the southern half, no arc volcanism or intermediate depth earthquakes occur at present, although knowledge of recent volcanic history is sparse. No slab seems to be present, li ...
... note, somewhat incidentally, that standard subduction is presently taking place only in the northern half of Costa Rica. In the southern half, no arc volcanism or intermediate depth earthquakes occur at present, although knowledge of recent volcanic history is sparse. No slab seems to be present, li ...
︎PDF - Fabio Crameri
... Subduction zones are one of the most prominent features on a planet that undergoes plate tectonics, not only in terms of surface morphology but also in terms of the planet’s dynamic evolution. Its importance for the dynamics is highlighted by the fact that the sinking portions of a plate (i.e., slab ...
... Subduction zones are one of the most prominent features on a planet that undergoes plate tectonics, not only in terms of surface morphology but also in terms of the planet’s dynamic evolution. Its importance for the dynamics is highlighted by the fact that the sinking portions of a plate (i.e., slab ...
Upper mantle anisotropy beneath Australia and Tahiti from P
... wave. Using anisotropic reflectivity modeling SchultePelkum et al. [2001] have shown that P particle motion is sensitive to anisotropy only within a wavelength of the seismometer. Ppol should be therefore sensitive to surficial structures (upper crust) at high frequency (i.e., 1 Hz) and to lithosphe ...
... wave. Using anisotropic reflectivity modeling SchultePelkum et al. [2001] have shown that P particle motion is sensitive to anisotropy only within a wavelength of the seismometer. Ppol should be therefore sensitive to surficial structures (upper crust) at high frequency (i.e., 1 Hz) and to lithosphe ...
Subducting slabs: Jellyfishes in the Earth`s mantle
... velocity component in the z‐direction vanishes (free‐slip conditions). However, since the slab is considered “infinite” in our simulation, slab material is constantly added from the top. To simulate that, we do not update the geometry of the upper boundary of the slab from the computed velocity fiel ...
... velocity component in the z‐direction vanishes (free‐slip conditions). However, since the slab is considered “infinite” in our simulation, slab material is constantly added from the top. To simulate that, we do not update the geometry of the upper boundary of the slab from the computed velocity fiel ...
Subsidence in intracontinental basins due to dynamic topography
... The origin of anomalous tectonic subsidence (ATS) of large intracontinental basins long after their most recent phase of extension and last thermal perturbation is the subject of a long standing debate. We show that deep-Earth processes may contribute to the subsidence of these tectonically stable b ...
... The origin of anomalous tectonic subsidence (ATS) of large intracontinental basins long after their most recent phase of extension and last thermal perturbation is the subject of a long standing debate. We show that deep-Earth processes may contribute to the subsidence of these tectonically stable b ...
Cascadia subducting plate fluids channelled to fore
... Figure 3. The downdip limit of the seismogenic zone, full rupture, tremor is also well characterized for and transition to zero rupture. The geodetic constraints are red and yellow shaded, and the thermal constraints on four profiles Cascadia [e.g., Rogers and Dragert, 2003]. are shown by red, 350°C, ...
... Figure 3. The downdip limit of the seismogenic zone, full rupture, tremor is also well characterized for and transition to zero rupture. The geodetic constraints are red and yellow shaded, and the thermal constraints on four profiles Cascadia [e.g., Rogers and Dragert, 2003]. are shown by red, 350°C, ...
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.