Building and Destroying Continental Mantle - Cin
... Ocean basins are the surface expression of solid-state mantle convection with a mobile lid. Heat transfer in Earth’s deep interior is driven by thermally buoyant upwellings, but when the upwelling reaches the surface of Earth, the mechanism of vertical heat transfer becomes dominated by conduction, ...
... Ocean basins are the surface expression of solid-state mantle convection with a mobile lid. Heat transfer in Earth’s deep interior is driven by thermally buoyant upwellings, but when the upwelling reaches the surface of Earth, the mechanism of vertical heat transfer becomes dominated by conduction, ...
A climate induced transition in the tectonic style of a terrestrial planet
... activity, it has been suggested that it may have experienced an early episode of plate tectonics (Moresi and Solomatov, 1998; Turcotte, 1993) (this has also been suggested for Mars (Sleep, 1994; Nimmo and Stevenson, 2000)). Phillips et al. (2001) explored models with lithospheric recycling, akin to ...
... activity, it has been suggested that it may have experienced an early episode of plate tectonics (Moresi and Solomatov, 1998; Turcotte, 1993) (this has also been suggested for Mars (Sleep, 1994; Nimmo and Stevenson, 2000)). Phillips et al. (2001) explored models with lithospheric recycling, akin to ...
a collisional model for the Grenville-aged orogenic belt - Cin
... of the uplift and explains uplift and exhumation of high-pressure eclogitic rocks, emplacement of ophiolitic rocks, and subsequent late-stage to postcollisional plutonism. Our model proposes that subduction with southward polarity resulted in collision of an exotic arc with Laurentia, emplacement of ...
... of the uplift and explains uplift and exhumation of high-pressure eclogitic rocks, emplacement of ophiolitic rocks, and subsequent late-stage to postcollisional plutonism. Our model proposes that subduction with southward polarity resulted in collision of an exotic arc with Laurentia, emplacement of ...
- Wiley Online Library
... may recover during future earthquakes in the subduction zone. Using a two-dimensional viscoelastoplastic finite element model, we investigate here how the cyclic trench coupling leads to long-term mountain building, which has been concentrated in the Subandes in the past few million years. Our resul ...
... may recover during future earthquakes in the subduction zone. Using a two-dimensional viscoelastoplastic finite element model, we investigate here how the cyclic trench coupling leads to long-term mountain building, which has been concentrated in the Subandes in the past few million years. Our resul ...
Advances in Environmental Biology
... require a prominent fractionation [14]. Low MgO concentrations of the samples of the felsic intrusion and other geochemical parameters rule out a direct derivation from mantle wedge. All these indicate a later and new parental melt for the felsic part rather than generation from the mafic rocks by f ...
... require a prominent fractionation [14]. Low MgO concentrations of the samples of the felsic intrusion and other geochemical parameters rule out a direct derivation from mantle wedge. All these indicate a later and new parental melt for the felsic part rather than generation from the mafic rocks by f ...
Indonesia The geology and tectonic evolution of the Bacan region
... deformation and recrystallization history, typical of Barrovian type dynamo-thermal metamorphism (Brouwer 1923; Hall et al. 1988). There is also evidence for retrograde metamorphism associated with post peak-metamorphism deformation. The protoliths were pelites with minor amounts of sandy and carbon ...
... deformation and recrystallization history, typical of Barrovian type dynamo-thermal metamorphism (Brouwer 1923; Hall et al. 1988). There is also evidence for retrograde metamorphism associated with post peak-metamorphism deformation. The protoliths were pelites with minor amounts of sandy and carbon ...
Pulsing of a focused mantle plume: Evidence from the distribution of
... [7] We cannot resolve differences in age across individual, similarly sized and oriented, zones of Foundation midplate volcanism created at a rate of approximately once per Myr. A physical process is therefore required that periodically brings masses of hot plume material extremely fast from depth a ...
... [7] We cannot resolve differences in age across individual, similarly sized and oriented, zones of Foundation midplate volcanism created at a rate of approximately once per Myr. A physical process is therefore required that periodically brings masses of hot plume material extremely fast from depth a ...
Polarized plate tectonics
... and therefore the tidal despinning can contribute to plate tectonics through the westward lithospheric drift (Bostrom, 1971; Knopoff and Leeds, 1972). Small perturbations in the velocity of rotation trigger the release of a large amount of energy and seismicity (Press and Briggs, ...
... and therefore the tidal despinning can contribute to plate tectonics through the westward lithospheric drift (Bostrom, 1971; Knopoff and Leeds, 1972). Small perturbations in the velocity of rotation trigger the release of a large amount of energy and seismicity (Press and Briggs, ...
The evolving nature of terrestrial crust from the Hadean, through the
... times of apparently much poorer crust preservation. It is concluded that two different paths led to formation of preserved Archaean continental crust. The first was the stabilisation of lithosphere at the Hadean–Archaean boundary, eventually giving rise to the long-lived, relatively slowly maturing, ...
... times of apparently much poorer crust preservation. It is concluded that two different paths led to formation of preserved Archaean continental crust. The first was the stabilisation of lithosphere at the Hadean–Archaean boundary, eventually giving rise to the long-lived, relatively slowly maturing, ...
Extensional inheritance and surface processes as controlling factors
... those in which the upper part of the lithospheric mantle subducts with little internal deformation and bulk shortening and where crustal thickening and heating are limited. In contrast, large-hot orogens are typically composed of a central elevated plateau underlain by thick crust and underthrusted ...
... those in which the upper part of the lithospheric mantle subducts with little internal deformation and bulk shortening and where crustal thickening and heating are limited. In contrast, large-hot orogens are typically composed of a central elevated plateau underlain by thick crust and underthrusted ...
Petrologic and thermal constraints on the origin of leucogranites in
... orogenic terranes of different ages, including the Proterozoic Trans-Hudson orogen, as exemplified in the Black Hills, South Dakota, and the Appalachian orogen in Maine, both in the USA, and the ongoing Himalayan orogen. Characteristics of these collisional leucogranites show that they were derived ...
... orogenic terranes of different ages, including the Proterozoic Trans-Hudson orogen, as exemplified in the Black Hills, South Dakota, and the Appalachian orogen in Maine, both in the USA, and the ongoing Himalayan orogen. Characteristics of these collisional leucogranites show that they were derived ...
EPSL94HokeHelium3Alt.. - University of Colorado Boulder
... We report results of a regional survey of helium isotopes measured in water and gas samples in volcanic sulfataras and geothermal springs from the Central Andes of northern Chile and Bolivia between the latitudes 15°S and 23°S. The highest 3 H e / 4 H e ratios (reported as R / R A ratios: R = sample ...
... We report results of a regional survey of helium isotopes measured in water and gas samples in volcanic sulfataras and geothermal springs from the Central Andes of northern Chile and Bolivia between the latitudes 15°S and 23°S. The highest 3 H e / 4 H e ratios (reported as R / R A ratios: R = sample ...
File - Qatar Science
... What are Igneous Rocks? Igneous rocks are formed from the solidification of molten rock material. There are two basic types. Intrusive igneous rocks crystallize below Earth's surface and the slow cooling that occurs there allows large crystals to form. An example of an intrusive igneous rocks is gra ...
... What are Igneous Rocks? Igneous rocks are formed from the solidification of molten rock material. There are two basic types. Intrusive igneous rocks crystallize below Earth's surface and the slow cooling that occurs there allows large crystals to form. An example of an intrusive igneous rocks is gra ...
Geodynpub_files/Boutelier, Chemenda, 2011
... When the density of the subducted lithosphere is significantly larger than that of the surrounding mantle, the negative buoyancy of the subducted slab generates a downward pull force Fsp, which results in a tensile non‐hydrostatic normal stress sn on the interplate zone. The magnitude of this stress ...
... When the density of the subducted lithosphere is significantly larger than that of the surrounding mantle, the negative buoyancy of the subducted slab generates a downward pull force Fsp, which results in a tensile non‐hydrostatic normal stress sn on the interplate zone. The magnitude of this stress ...
Generation of plate tectonics from mantle convection
... The mathematical or Euler pole theory of plate tectonics is a kinematic depiction of motion, but not causative since it does not describe the dynamics or driving forces for plate tectonics. Much of this chapter is about how the mantle convective engine is related to or even causes plate tectonics. H ...
... The mathematical or Euler pole theory of plate tectonics is a kinematic depiction of motion, but not causative since it does not describe the dynamics or driving forces for plate tectonics. Much of this chapter is about how the mantle convective engine is related to or even causes plate tectonics. H ...
Lithospheric thickness under the Dinarides
... stations have been exploited to create receiver functions. Both PRFs and SRFs show a coherent phases that gives consistent results for the lithospheric structure. The converted phases are due to a sharp velocity increase for Moho and decrease for LAB that occurs at variable depth across the study re ...
... stations have been exploited to create receiver functions. Both PRFs and SRFs show a coherent phases that gives consistent results for the lithospheric structure. The converted phases are due to a sharp velocity increase for Moho and decrease for LAB that occurs at variable depth across the study re ...
Tectonics III: Hot-‐spots and mantle plumes
... Iceland is a modern example to a plume co-‐located with a mid-‐oceanic ridge. ...
... Iceland is a modern example to a plume co-‐located with a mid-‐oceanic ridge. ...
Key - Scioly.org
... 11. A sheet intrusion of magma that causes overlying strata to bulge upward into a dome-like form is called? A. Sill B. Dike C. Batholith D. Laccolith 12. Which of the following is true regarding P waves and S waves? A. S waves travel faster than P waves B. P waves can only travel through solids C. ...
... 11. A sheet intrusion of magma that causes overlying strata to bulge upward into a dome-like form is called? A. Sill B. Dike C. Batholith D. Laccolith 12. Which of the following is true regarding P waves and S waves? A. S waves travel faster than P waves B. P waves can only travel through solids C. ...
Focus in Action Learning Pack
... - forms when hot magma (or lava) cools and solidifies - Magma is melted rock found below the Earth’s crust - Types of Igneous rock are: • intrusive (cooled and hardened magma below the Earth’s surface • extrusive (rock that forms when lava – magma released during a volcanic eruption - cools on the s ...
... - forms when hot magma (or lava) cools and solidifies - Magma is melted rock found below the Earth’s crust - Types of Igneous rock are: • intrusive (cooled and hardened magma below the Earth’s surface • extrusive (rock that forms when lava – magma released during a volcanic eruption - cools on the s ...
Subduction factory 2. Are intermediate
... observations imply that dehydration in subducting slabs could cause seismicity. Connolly [1997] and Hacker [1997] have emphasized that even reactions with a negative total volume change can lead to elevated fluid pressures over the timescale at which the rock can creep or become sealed. [12] As an o ...
... observations imply that dehydration in subducting slabs could cause seismicity. Connolly [1997] and Hacker [1997] have emphasized that even reactions with a negative total volume change can lead to elevated fluid pressures over the timescale at which the rock can creep or become sealed. [12] As an o ...
Chukchi arctic continental margins: tectonic evolution, link to the
... continental nature of the Lomonosov Ridge crust and an oceanic nature of the Canada Basin crust are more or less proven. However, seismic data available for the crust of the Alpha Ridge and the Mendeleev Uplift cannot currently be unambiguously interpreted based on available evidence. In this contex ...
... continental nature of the Lomonosov Ridge crust and an oceanic nature of the Canada Basin crust are more or less proven. However, seismic data available for the crust of the Alpha Ridge and the Mendeleev Uplift cannot currently be unambiguously interpreted based on available evidence. In this contex ...
Geodynamics of the South China Sea
... The beginning of seafloor spreading in the South China Sea (SCS) is now established from IODP drilling Leg 349 at 33 Ma. Chron 12 (32 Ma) is the oldest chron identified in the SCS. The nature of the crust of the northeastern part of the SCS located north of chron C12, where chrons 15 to 17 were previo ...
... The beginning of seafloor spreading in the South China Sea (SCS) is now established from IODP drilling Leg 349 at 33 Ma. Chron 12 (32 Ma) is the oldest chron identified in the SCS. The nature of the crust of the northeastern part of the SCS located north of chron C12, where chrons 15 to 17 were previo ...
The anatomy and ontogeny of modern intra
... subducted plate reaches magmagenetic depths (100 –150 km) and causes the mantle to melt. This configuration must exist for long enough that melts generated in the overlying asthenospheric wedge not only reach the surface but also persist until a stable magmatic conduit system is established. When th ...
... subducted plate reaches magmagenetic depths (100 –150 km) and causes the mantle to melt. This configuration must exist for long enough that melts generated in the overlying asthenospheric wedge not only reach the surface but also persist until a stable magmatic conduit system is established. When th ...
Plate tectonics
Plate tectonics (from the Late Latin tectonicus, from the Greek: τεκτονικός ""pertaining to building"") is a scientific theory that describes the large-scale motion of Earth's lithosphere. This theoretical model builds on the concept of continental drift which was developed during the first few decades of the 20th century. The geoscientific community accepted the theory after the concepts of seafloor spreading were later developed in the late 1950s and early 1960s.The lithosphere, which is the rigid outermost shell of a planet (on Earth, the crust and upper mantle), is broken up into tectonic plates. On Earth, there are seven or eight major plates (depending on how they are defined) and many minor plates. Where plates meet, their relative motion determines the type of boundary; convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The lateral relative movement of the plates typically varies from zero to 100 mm annually.Tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle; the material lost is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading. In this way, the total surface of the globe remains the same. This prediction of plate tectonics is also referred to as the conveyor belt principle. Earlier theories (that still have some supporters) propose gradual shrinking (contraction) or gradual expansion of the globe.Tectonic plates are able to move because the Earth's lithosphere has greater strength than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the spreading ridge (due to variations in topography and density of the crust, which result in differences in gravitational forces) and drag, with downward suction, at the subduction zones. Another explanation lies in the different forces generated by the rotation of the globe and the tidal forces of the Sun and Moon. The relative importance of each of these factors and their relationship to each other is unclear, and still the subject of much debate.