Evidence for mantle metasomatism by hydrous silicic - HAL-Insu
... The above experimental evidence bears direct constraints on metasomatic processes in arc settings. The low-temperature, fluid-present melting conditions above suggest that slab melting can occur in presently subducting plates, as previously suggested on geochemical grounds 5. Although slab melting w ...
... The above experimental evidence bears direct constraints on metasomatic processes in arc settings. The low-temperature, fluid-present melting conditions above suggest that slab melting can occur in presently subducting plates, as previously suggested on geochemical grounds 5. Although slab melting w ...
The importance of radiative heat transfer on superplumes in the
... (endothermic phase change) at the same depth of 2650 km. Surprisingly, in the case P = 0.05 we have obtained lower stability of the superplume, which is demonstrated in Fig. 2b. It exhibits pulsations, which originate from the lower boundary layer instabilities that are attracted by the superplume. ...
... (endothermic phase change) at the same depth of 2650 km. Surprisingly, in the case P = 0.05 we have obtained lower stability of the superplume, which is demonstrated in Fig. 2b. It exhibits pulsations, which originate from the lower boundary layer instabilities that are attracted by the superplume. ...
Topography and geoid due to lithospheric mass anomalies
... flattening of the sea-floor topography at age larger than 100 Ma is associated with lithospheric processes, one should conclude that no dynamic topography is observed (Colin & Fleitout 1990). Even if this flattening is due to deep-mantle effects, only some 500 m peak-to-peak topography can be associ ...
... flattening of the sea-floor topography at age larger than 100 Ma is associated with lithospheric processes, one should conclude that no dynamic topography is observed (Colin & Fleitout 1990). Even if this flattening is due to deep-mantle effects, only some 500 m peak-to-peak topography can be associ ...
Regional anomalies of sediment thickness, basement depth and
... varying amounts of tectonic extension and subsidence (see [28] for a more detailed description of sediment thickness variations offshore eastern Canada). Near-zero thicknesses occur over unrifted basement blocks, while sediments more than 10 km thick commonly fill adjacent rift basins. Conjugate mar ...
... varying amounts of tectonic extension and subsidence (see [28] for a more detailed description of sediment thickness variations offshore eastern Canada). Near-zero thicknesses occur over unrifted basement blocks, while sediments more than 10 km thick commonly fill adjacent rift basins. Conjugate mar ...
Important Technical Terms
... The specific data that led Reid to his elastic rebound theory consisted of land surveys conducted immediately after the 1906 earthquake and older land surveys that had been completed between 1851 and 1906. When Reid compared the postearthquake surveys with the older surveys, he detected an interesti ...
... The specific data that led Reid to his elastic rebound theory consisted of land surveys conducted immediately after the 1906 earthquake and older land surveys that had been completed between 1851 and 1906. When Reid compared the postearthquake surveys with the older surveys, he detected an interesti ...
PLATE TECTONICS
... The breakup of continents begins as the rising portion of a asthenospheric convection encounters the bottom of the lithosphere and creates tensional forces within the overlying lithosphere. The tensional forces create fractures in the lithosphere that appear on the surface as a linear zone called a ...
... The breakup of continents begins as the rising portion of a asthenospheric convection encounters the bottom of the lithosphere and creates tensional forces within the overlying lithosphere. The tensional forces create fractures in the lithosphere that appear on the surface as a linear zone called a ...
Microsoft Word
... The specific data that led Reid to his elastic rebound theory consisted of land surveys conducted immediately after the 1906 earthquake and older land surveys that had been completed between 1851 and 1906. When Reid compared the postearthquake surveys with the older surveys, he detected an interesti ...
... The specific data that led Reid to his elastic rebound theory consisted of land surveys conducted immediately after the 1906 earthquake and older land surveys that had been completed between 1851 and 1906. When Reid compared the postearthquake surveys with the older surveys, he detected an interesti ...
Earthquake
... • Anthropogenic: arising from the influence of humans • Humans can cause earthquakes, mainly due to changes in groundwater. This is called induced seismicity. • Groundwater pressure can push apart faults, thereby reducing the friction on the fault, causing it to slip (earthquake). – E.g. Denver, was ...
... • Anthropogenic: arising from the influence of humans • Humans can cause earthquakes, mainly due to changes in groundwater. This is called induced seismicity. • Groundwater pressure can push apart faults, thereby reducing the friction on the fault, causing it to slip (earthquake). – E.g. Denver, was ...
PLATE TECTONICS - Oakton Community College
... • Crustal materials float in asthenosphere (Fig. 14) p 20 • Weight of volcano bends crust (Fig 2.27) remember from last time. • Glaciers also cause crust so subside (a process by which one plate descends beneath another plate and is ultimately resorbed into the mantle) PLATE TECTONICS ...
... • Crustal materials float in asthenosphere (Fig. 14) p 20 • Weight of volcano bends crust (Fig 2.27) remember from last time. • Glaciers also cause crust so subside (a process by which one plate descends beneath another plate and is ultimately resorbed into the mantle) PLATE TECTONICS ...
Bounds on the viscosity coefficient of continental lithosphere from
... there is no obvious source of the volume of crustal material that must be injected into crust beneath these regions. In fact, crustal thickening in the Eastern and Western Cordilleras associated with crustal shortening and magmatism should result in a source of excess lower crustal material from the ...
... there is no obvious source of the volume of crustal material that must be injected into crust beneath these regions. In fact, crustal thickening in the Eastern and Western Cordilleras associated with crustal shortening and magmatism should result in a source of excess lower crustal material from the ...
A comprehensive model of the deformation process in the Nagamachi-Rifu
... however, they quickly diminish and the effect of the heterogeneity is dominant for latter periods. Residual horizontal and vertical velocity profiles are illustrated for all of the heterogeneities for the 20 years before the next interplate earthquake in the upper and lower panels in Fig. 5, respect ...
... however, they quickly diminish and the effect of the heterogeneity is dominant for latter periods. Residual horizontal and vertical velocity profiles are illustrated for all of the heterogeneities for the 20 years before the next interplate earthquake in the upper and lower panels in Fig. 5, respect ...
Perspective - Elements Magazine
... seafloor where geochemists can sample and analyze the lavas so as to better understand mantle and bulk-Earth evolution. But structural and metamorphic geology are equally necessary, since ridge magmatism is necessarily synkinematic. The brittle carapace is dissected by multiple generations of faults ...
... seafloor where geochemists can sample and analyze the lavas so as to better understand mantle and bulk-Earth evolution. But structural and metamorphic geology are equally necessary, since ridge magmatism is necessarily synkinematic. The brittle carapace is dissected by multiple generations of faults ...
Top driven asymmetric mantle convection
... The volumes of lithospheric loss must be compensated by the same amount of mantle upwelling. If there are 306 km3/yr of lithospheric loss, we expect the same amount of lithospheric production. New oceanic lithosphere is formed along the about 60,000 km long oceanic ridges and backarc basin systems. ...
... The volumes of lithospheric loss must be compensated by the same amount of mantle upwelling. If there are 306 km3/yr of lithospheric loss, we expect the same amount of lithospheric production. New oceanic lithosphere is formed along the about 60,000 km long oceanic ridges and backarc basin systems. ...
Hydrated subducted crust at 100^250 km depth
... thickness of subducted sediment inferred for these arcs [13]. We conclude that subducted crust, or a parallel nearby layer of comparable thickness, persists as a LVL to considerable depth in most subduction zones. The one known exception is the reported pattern for Tonga, where high frequencies prec ...
... thickness of subducted sediment inferred for these arcs [13]. We conclude that subducted crust, or a parallel nearby layer of comparable thickness, persists as a LVL to considerable depth in most subduction zones. The one known exception is the reported pattern for Tonga, where high frequencies prec ...
Origin and time evolution of subduction polarity reversal from plate
... associated with plate deformation; however, it is an appropriate tool to trace polarity reversals through time. Our model can be seen as a locally refined version of the model of Seton et al. (2012) adjusted to fit geological constraints on the evolution of the Taiwan area (see the Data Repository). ...
... associated with plate deformation; however, it is an appropriate tool to trace polarity reversals through time. Our model can be seen as a locally refined version of the model of Seton et al. (2012) adjusted to fit geological constraints on the evolution of the Taiwan area (see the Data Repository). ...
Chapter 10 Section 2
... • Tectonic plate boundaries may be in the middle of the ocean floor, around the edges of continents, or even within continents. • The three types of plate boundaries are – divergent boundaries – convergent boundaries – transform boundaries • Each plate boundary is associated with a characteristic ty ...
... • Tectonic plate boundaries may be in the middle of the ocean floor, around the edges of continents, or even within continents. • The three types of plate boundaries are – divergent boundaries – convergent boundaries – transform boundaries • Each plate boundary is associated with a characteristic ty ...
Molnar, P., and C. N. Garzione (2007), Bounds on the viscosity coefficient of continental lithosphere
... that must be injected into crust beneath these regions. In fact, crustal thickening in the Eastern and Western Cordilleras associated with crustal shortening and magmatism should result in a source of excess lower crustal material from the cordilleras, not injection of material beneath them. [8] Con ...
... that must be injected into crust beneath these regions. In fact, crustal thickening in the Eastern and Western Cordilleras associated with crustal shortening and magmatism should result in a source of excess lower crustal material from the cordilleras, not injection of material beneath them. [8] Con ...
On the shallow origin of hotspots and the westward drift of the
... On the shallow origin of hotspots and the westward drift of the lithosphere The ITRF2000 model (e.g., Heflin et al., 2003) is excellent for describing relative plate motions and is also considered an absolute reference frame (relative to the Global Positioning System constellation or the Earth’s ce ...
... On the shallow origin of hotspots and the westward drift of the lithosphere The ITRF2000 model (e.g., Heflin et al., 2003) is excellent for describing relative plate motions and is also considered an absolute reference frame (relative to the Global Positioning System constellation or the Earth’s ce ...
Thermo-mechanical model of the Dead Sea Transform
... the Arabian and African plates marked by the Dead Sea Transform (DST), that accommodated ca 105 km of relative transform displacement during the last 20 Myr. We show that in the initially cold lithosphere expected at the DST, shear deformation localizes in a 20–40 km wide zone where temperature-cont ...
... the Arabian and African plates marked by the Dead Sea Transform (DST), that accommodated ca 105 km of relative transform displacement during the last 20 Myr. We show that in the initially cold lithosphere expected at the DST, shear deformation localizes in a 20–40 km wide zone where temperature-cont ...
Three-dimensional density model of the upper mantle in
... methods also require global distribution of all parameters (see below). Although the model of Schaeffer and Lebedev [2013] is global, it is characterized by high horizontal resolution compared to other global models and reasonably agrees with existing regional models [e.g., Chang and Van der Lee, 20 ...
... methods also require global distribution of all parameters (see below). Although the model of Schaeffer and Lebedev [2013] is global, it is characterized by high horizontal resolution compared to other global models and reasonably agrees with existing regional models [e.g., Chang and Van der Lee, 20 ...
Origin of the Newberry Hotspot Track: Evidence from
... signature, which are characteristic of many hotspots. Yet, despite these features, evidence for an upwelling conduit through the upper mantle beneath Yellowstone remains unclear and the debate continues as to whether a mantle plume is the origin [3,10–15]. The Newberry hotspot is far less studied th ...
... signature, which are characteristic of many hotspots. Yet, despite these features, evidence for an upwelling conduit through the upper mantle beneath Yellowstone remains unclear and the debate continues as to whether a mantle plume is the origin [3,10–15]. The Newberry hotspot is far less studied th ...
Non-hotspot formation of volcanic chains
... be controlled by large scale mantle processes such as convection under the superswell [28] or return mantle £ow toward the EPR from the superswell bringing in anomalously hot asthenosphere material [28,29], resulting in an abundant melt supply throughout much of the superswell region and near the EP ...
... be controlled by large scale mantle processes such as convection under the superswell [28] or return mantle £ow toward the EPR from the superswell bringing in anomalously hot asthenosphere material [28,29], resulting in an abundant melt supply throughout much of the superswell region and near the EP ...
133_2011_Coblentz et al_Geosystems_Rocky Mtns
... that suggest an intimate relationship between mantle geodynamic processes and the surface topography. The region is in isostatic equilibrium (i.e., near‐zero free‐air gravity anomaly); however, the poor correlation between the high topography and crustal thickness makes the application of simple com ...
... that suggest an intimate relationship between mantle geodynamic processes and the surface topography. The region is in isostatic equilibrium (i.e., near‐zero free‐air gravity anomaly); however, the poor correlation between the high topography and crustal thickness makes the application of simple com ...
Lecture 18
... interpretation is that whereas White argued that each reservoir type many consist of many reservoirs, but all had evolved through similar processes, Zindler and Hart (1986) argued that five distinct reservoirs exist, and that variations in isotope ratios result from mixing of these reservoirs. lands ...
... interpretation is that whereas White argued that each reservoir type many consist of many reservoirs, but all had evolved through similar processes, Zindler and Hart (1986) argued that five distinct reservoirs exist, and that variations in isotope ratios result from mixing of these reservoirs. lands ...
Glossary a - Teacher Friendly Guides
... a marine invertebrate animal belonging to the Phylum Brachiopoda, and characterized by upper and lower calcareous shell valves joined by a hinge, and a crown of tentacles (lophophore) used for filterfeeding and respiration. Brachiopods are the most common fossil in Paleozoic sedimentary rocks. Brach ...
... a marine invertebrate animal belonging to the Phylum Brachiopoda, and characterized by upper and lower calcareous shell valves joined by a hinge, and a crown of tentacles (lophophore) used for filterfeeding and respiration. Brachiopods are the most common fossil in Paleozoic sedimentary rocks. Brach ...
Post-glacial rebound
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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.