The Eclogite Engine: Chemical geodynamics as
... The mantle is a machine that converts energy into mechanical forces and motions. It is therefore an engine. In the eclogite engine the working fluids are not water and steam but basalt, eclogite and magma, and packages of the same. At the top of the system, magma and basalt are converted to dense ec ...
... The mantle is a machine that converts energy into mechanical forces and motions. It is therefore an engine. In the eclogite engine the working fluids are not water and steam but basalt, eclogite and magma, and packages of the same. At the top of the system, magma and basalt are converted to dense ec ...
Space geodesy validation of the global lithospheric flow
... Space geodesy data are used to verify whether plates move chaotically or rather follow a sort of tectonic mainstream. While independent lines of geological evidence support the existence of a global ordered flow of plate motions that is westerly polarized, the Terrestrial Reference Frame (TRF) prese ...
... Space geodesy data are used to verify whether plates move chaotically or rather follow a sort of tectonic mainstream. While independent lines of geological evidence support the existence of a global ordered flow of plate motions that is westerly polarized, the Terrestrial Reference Frame (TRF) prese ...
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 ...
Initiation of Subduction Zones as a Consequence
... respect to the asthenosphere. Therefore, it would be physically optimal if one part of the lithosphere experienced a greater gravitational attraction than its adjacent neighbour before or during the initiation of a subduction zone. This requires the pre-existence of a density contrast within the lit ...
... respect to the asthenosphere. Therefore, it would be physically optimal if one part of the lithosphere experienced a greater gravitational attraction than its adjacent neighbour before or during the initiation of a subduction zone. This requires the pre-existence of a density contrast within the lit ...
Hilliker 1 The Effects of the Farallon Plate Subduction Frank Hilliker
... mantle activity due to the subducted Farallon Plate. The figure on page 4 (section D) shows the relative position of the Farallon Plate beneath the North American Plate as of this time. Scaling the Section D map on page four to the dimensions of the maps on page nine will demonstrate that the NMSZ w ...
... mantle activity due to the subducted Farallon Plate. The figure on page 4 (section D) shows the relative position of the Farallon Plate beneath the North American Plate as of this time. Scaling the Section D map on page four to the dimensions of the maps on page nine will demonstrate that the NMSZ w ...
Influence of Membrane Stress on Seafloor Spreading
... Therefore, we propose that the thin-shell theory can be used to analyze the dynamic effect of the tidal force on the crust. Our findings are not only a theoretical support of the proposition that mid-ocean ridge fracturing and plate motions originate from the lunar-solar tidal force, but they are al ...
... Therefore, we propose that the thin-shell theory can be used to analyze the dynamic effect of the tidal force on the crust. Our findings are not only a theoretical support of the proposition that mid-ocean ridge fracturing and plate motions originate from the lunar-solar tidal force, but they are al ...
Initiation of the Andean orogeny by lower mantle subduction
... pressure within the sub-slab mantle in the center of the slab prevents slab retreat. Long (along trench) subduction zones would be expected to migrate backward slower due to the increasing resistance of the sub-slab mantle (e.g., Schellart et al., 2007). However, this model is unable to explain why ...
... pressure within the sub-slab mantle in the center of the slab prevents slab retreat. Long (along trench) subduction zones would be expected to migrate backward slower due to the increasing resistance of the sub-slab mantle (e.g., Schellart et al., 2007). However, this model is unable to explain why ...
Rhenium–osmium isotope and elemental behaviour during
... basalts (MORB) sample mantle material that is depleted in incompatible elements, and this depletion is generally attributed to the extraction and generation of continental crust. In contrast, ocean-island basalts (OIB) are relatively enriched in many incompatible elements which is thought to reflect ...
... basalts (MORB) sample mantle material that is depleted in incompatible elements, and this depletion is generally attributed to the extraction and generation of continental crust. In contrast, ocean-island basalts (OIB) are relatively enriched in many incompatible elements which is thought to reflect ...
Plate tectonics began in Neoproterozoic time
... characteristics (Anderson, in press). Shearing also smears out deep subcontinental lithospheric mantle. Subduction did not operate during most of Precambrian time, but delaminated protocrustal materials presumably then also sank no deeper than the transition zone (Section 3.1), which, however, would ...
... characteristics (Anderson, in press). Shearing also smears out deep subcontinental lithospheric mantle. Subduction did not operate during most of Precambrian time, but delaminated protocrustal materials presumably then also sank no deeper than the transition zone (Section 3.1), which, however, would ...
Earth Science Chapter 18: Volcanic Activity Chapter Overview
... • Divergent volcanism – at divergent boundaries tectonic plates move apart and new ocean floor is produced as magma rises to fill the gap. At these ridges, the lava takes the form of giant pillows. Volcanism at divergent boundaries tends to be non-explosive. • Hot spots – some volcanoes form far fro ...
... • Divergent volcanism – at divergent boundaries tectonic plates move apart and new ocean floor is produced as magma rises to fill the gap. At these ridges, the lava takes the form of giant pillows. Volcanism at divergent boundaries tends to be non-explosive. • Hot spots – some volcanoes form far fro ...
Geophysical and petrological modelling of the
... geophysical investigation and by studies of petrology–geochemistry of magmatic rocks and entrained xenoliths. Integration of petrological and geophysical studies is particularly useful in geodynamically complex areas characterised by abundant and compositionally variable young magmatism, such as in ...
... geophysical investigation and by studies of petrology–geochemistry of magmatic rocks and entrained xenoliths. Integration of petrological and geophysical studies is particularly useful in geodynamically complex areas characterised by abundant and compositionally variable young magmatism, such as in ...
Terrestrial Planet Evolution in the Stagnant
... where Rm is the radius of the mantle; Qm is the volumetric heat production of the mantle; ρm is the density of the mantle; Cm is the specific heat of the mantle; ηm is the ratio of the average temperature of the mantle to Tu , the potential temperature of the mantle (a hypothetical temperature of th ...
... where Rm is the radius of the mantle; Qm is the volumetric heat production of the mantle; ρm is the density of the mantle; Cm is the specific heat of the mantle; ηm is the ratio of the average temperature of the mantle to Tu , the potential temperature of the mantle (a hypothetical temperature of th ...
Contents and Preface
... the continental lithosphere, affected by a much longer geological evolution and characterized by significant heterogeneity in both its crustal and mantle components. By now, the lithosphere is probably the best studied part of the plate-tectonics system. Seismic tomography has led to the realization ...
... the continental lithosphere, affected by a much longer geological evolution and characterized by significant heterogeneity in both its crustal and mantle components. By now, the lithosphere is probably the best studied part of the plate-tectonics system. Seismic tomography has led to the realization ...
ES 106 Laboratory # 4 - Western Oregon University
... animals, as well as many other geologic processes. Using information from the ocean basins, including topography, age, and mechanisms of their evolution, Earth scientists have developed the exciting theory called plate tectonics. Plate tectonics states that Earth’s surface is broken in to rigid slab ...
... animals, as well as many other geologic processes. Using information from the ocean basins, including topography, age, and mechanisms of their evolution, Earth scientists have developed the exciting theory called plate tectonics. Plate tectonics states that Earth’s surface is broken in to rigid slab ...
Travel Time Tomographic Imaging of Shallow Fore
... Below left: Resolvability of the final model is assessed using checkerboard pattern tests with different anomaly sizes. We then compare our tomographically-derived velocity models to coincident seismic reflection images post-stack time migrated and converted to depth using our results (below right). ...
... Below left: Resolvability of the final model is assessed using checkerboard pattern tests with different anomaly sizes. We then compare our tomographically-derived velocity models to coincident seismic reflection images post-stack time migrated and converted to depth using our results (below right). ...
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... suggesting that the compositions of continental crust must also vary greatly. This agrees with what has been learned about the different ways continents can form, discussed in Chapter 14. In general, however, continents have a density of about 2.7 gm/cm3, which is much lower than both oceanic crust ...
... suggesting that the compositions of continental crust must also vary greatly. This agrees with what has been learned about the different ways continents can form, discussed in Chapter 14. In general, however, continents have a density of about 2.7 gm/cm3, which is much lower than both oceanic crust ...
Convergent-Boundary Mountains
... – Seafloor structures, such as seamounts, must also be in isostatic equilibrium with the mantle. – Elevation of Earth’s crust depends upon the thickness of the crust as well as its density. – Mountain roots can be many times as deep as a mountain is high. ...
... – Seafloor structures, such as seamounts, must also be in isostatic equilibrium with the mantle. – Elevation of Earth’s crust depends upon the thickness of the crust as well as its density. – Mountain roots can be many times as deep as a mountain is high. ...
Implications of Subduction Rehydration for Earth`s Deep
... see [Hofmann, 1997] for a review) which leave their fingerprints on observed basalts to which their melts contribute, with arrays of basalts produced at a given hotspot typically occupying a tubelike subregion in the isotope-space spanned by terrestrial basaltic volcanism [Hart, et al., 1992; Phipps ...
... see [Hofmann, 1997] for a review) which leave their fingerprints on observed basalts to which their melts contribute, with arrays of basalts produced at a given hotspot typically occupying a tubelike subregion in the isotope-space spanned by terrestrial basaltic volcanism [Hart, et al., 1992; Phipps ...
Without hot rock, much of North America would be underwater
... American elevations high, most of the continent would be below sea level, except the high Rocky “We found a good explanation for the elevation of Mountains, the Sierra Nevada and the Pacific continents,” Hasterok says. “We now know why Northwest west of the Cascade Range,” says some areas are higher ...
... American elevations high, most of the continent would be below sea level, except the high Rocky “We found a good explanation for the elevation of Mountains, the Sierra Nevada and the Pacific continents,” Hasterok says. “We now know why Northwest west of the Cascade Range,” says some areas are higher ...
- Wiley Online Library
... used to study the mechanisms of lithosphere extension and the parameters governing the geometry of rifted structures (e.g., influence of the extension rate, Bassi [1995], Van Wijk and Cloetingh [2002], Huismans and Beaumont [2003], Burov [2007] or of the thermal structure of the lithosphere, Chery e ...
... used to study the mechanisms of lithosphere extension and the parameters governing the geometry of rifted structures (e.g., influence of the extension rate, Bassi [1995], Van Wijk and Cloetingh [2002], Huismans and Beaumont [2003], Burov [2007] or of the thermal structure of the lithosphere, Chery e ...
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.