The role of magmatically driven lithospheric thickening on arc front
... 1. Introduction One of the most distinctive geographic features on Earth is the series of long arcuate chains of volcanoes on the upper plate of subduction zones, where cold and hydrothermally altered oceanic lithosphere descends into the Earth’s deep interior. Arc volcanism forms one of the primary ...
... 1. Introduction One of the most distinctive geographic features on Earth is the series of long arcuate chains of volcanoes on the upper plate of subduction zones, where cold and hydrothermally altered oceanic lithosphere descends into the Earth’s deep interior. Arc volcanism forms one of the primary ...
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... and volcanic activity, such (Beydoun 1970; Colemanet al. 1975,1979) and on the Outer Voring Plateau,Norway' where layered yolcanic flows have been detected from seismicdata (Mutter, Talwani & Stoffa 1982) and from drilling results (Talwani & Udintsev 1976). The magnetic quiet zone oceanic lithospher ...
... and volcanic activity, such (Beydoun 1970; Colemanet al. 1975,1979) and on the Outer Voring Plateau,Norway' where layered yolcanic flows have been detected from seismicdata (Mutter, Talwani & Stoffa 1982) and from drilling results (Talwani & Udintsev 1976). The magnetic quiet zone oceanic lithospher ...
Electromagnetic imaging of magma across the Narmada Son lineament, central India
... field, using the induction coil magnetometers. Data were analyzed using a single site analysis procedure. The analysis was done using the robust processing technique (Jones and Jödicke, 1984) for obtaining the auto and cross power spectra required for computing the frequency variation of the appare ...
... field, using the induction coil magnetometers. Data were analyzed using a single site analysis procedure. The analysis was done using the robust processing technique (Jones and Jödicke, 1984) for obtaining the auto and cross power spectra required for computing the frequency variation of the appare ...
Solid or Liquid? Rock Behavior Within Earth
... of volcanoes and earthquakes suggested that continents were just parts of enormous “plates” that make up outer Earth. They proposed that as these plates moved and their edges interacted, earthquakes were generated, and magma rose to the surface between plates, producing volcanoes. Many geoscientist ...
... of volcanoes and earthquakes suggested that continents were just parts of enormous “plates” that make up outer Earth. They proposed that as these plates moved and their edges interacted, earthquakes were generated, and magma rose to the surface between plates, producing volcanoes. Many geoscientist ...
Earth Planet. Sci. Lett., 139, 1-16, 1996.
... 1211 averaged to 0.25” and corrected for the variations of sound speed in water, sediment loading and seafloor age, using the standard thermal-plate model [9]. The superswell hypothesis relies heavily on recognizing a depth anomaly which has a magnitude and spatial distribution inconsistent with the ...
... 1211 averaged to 0.25” and corrected for the variations of sound speed in water, sediment loading and seafloor age, using the standard thermal-plate model [9]. The superswell hypothesis relies heavily on recognizing a depth anomaly which has a magnitude and spatial distribution inconsistent with the ...
Anderson and Natland, 2005
... order to form mountain belts and rift plateaus. Plumes are currently being used in a similar way to rationalize features that are not readily explained by simple rigid plate tectonics and horizontal motions. Adherents of plate tectonics rapidly shunted aside Beloussov’s ideas of vertical tectonics, ...
... order to form mountain belts and rift plateaus. Plumes are currently being used in a similar way to rationalize features that are not readily explained by simple rigid plate tectonics and horizontal motions. Adherents of plate tectonics rapidly shunted aside Beloussov’s ideas of vertical tectonics, ...
RECOLLECTION The discovery of the Earth`s oldest rocks Stephen
... Downloaded from http://rsnr.royalsocietypublishing.org/ on April 29, 2017 ...
... Downloaded from http://rsnr.royalsocietypublishing.org/ on April 29, 2017 ...
On subducting slab entrainment of buoyant asthenosphere
... hence weak and buoyant asthenosphere layer we have simplified our setup for the numerical calculations in that phase transitions and melting processes are not considered. Instead, we begin with a preexisting 200 km-thick asthenosphere layer with a higher temperature and more depletion than the underl ...
... hence weak and buoyant asthenosphere layer we have simplified our setup for the numerical calculations in that phase transitions and melting processes are not considered. Instead, we begin with a preexisting 200 km-thick asthenosphere layer with a higher temperature and more depletion than the underl ...
Spontaneous development of arcuate single‐sided subduction in
... the studies reviewed above. Behavior such as the spontaneous development of subduction trench and slab curvature, trench migration, and subduction-induced mantle flow are of particular interest. To obtain realistic behavior, it is necessary for subduction to be single sided as observed on Earth, in c ...
... the studies reviewed above. Behavior such as the spontaneous development of subduction trench and slab curvature, trench migration, and subduction-induced mantle flow are of particular interest. To obtain realistic behavior, it is necessary for subduction to be single sided as observed on Earth, in c ...
RECOLLECTION The discovery of the Earth`s oldest rocks Stephen
... rocks by identifiable uniformitarian geological processes. Chemical sediments were precipitated in warm ocean water fed with iron-rich chemicals derived from hydrothermal vents discharging massive volumes of basaltic lavas into the water from the hot mantle below. Clastic sediments were produced clo ...
... rocks by identifiable uniformitarian geological processes. Chemical sediments were precipitated in warm ocean water fed with iron-rich chemicals derived from hydrothermal vents discharging massive volumes of basaltic lavas into the water from the hot mantle below. Clastic sediments were produced clo ...
tectonic evolution of the japanese island arc system
... Efforts to map the active faults (faults that show evidence of movement since the Quaternary) of the Japanese arc system by means of topographic analysis, field surveying, and trench excavation have continued for the past ∼30 years. The resulting collection of maps was published by Research Group of ...
... Efforts to map the active faults (faults that show evidence of movement since the Quaternary) of the Japanese arc system by means of topographic analysis, field surveying, and trench excavation have continued for the past ∼30 years. The resulting collection of maps was published by Research Group of ...
Karson, J.A., and Lawrence, R.M., 1997. Tectonic setting of
... of slow-spreading ridges and especially near ridge-transform intersections, stretching, thinning, and tectonic dismemberment of the axial lithosphere and crust will occur. Commonly, oceanic crust is thought to consist of a series of horizontally layered igneous rock units consisting of surficial bas ...
... of slow-spreading ridges and especially near ridge-transform intersections, stretching, thinning, and tectonic dismemberment of the axial lithosphere and crust will occur. Commonly, oceanic crust is thought to consist of a series of horizontally layered igneous rock units consisting of surficial bas ...
Lower crustal earthquakes near the Ethiopian rift induced by
... plateau is among the slowest worldwide [Bastow et al., 2008]. This observation, plus the ratio of teleseismic P and S wave delay times suggests these low-velocity anomalies cannot be explained by variations in composition and temperature alone and require the presence of a small fraction fluid phase ...
... plateau is among the slowest worldwide [Bastow et al., 2008]. This observation, plus the ratio of teleseismic P and S wave delay times suggests these low-velocity anomalies cannot be explained by variations in composition and temperature alone and require the presence of a small fraction fluid phase ...
Nature template - PC Word 97 - University of Colorado Boulder
... maintain ocean volume and continental freeboard over geologic time. Two tenths of one weight percent H2O in subducted oceanic crustal material and subsequently released to the hydrosphere from mid-ocean ridge basalt is sufficient to recycle the total ocean volume once over 4.5 billion years. It is p ...
... maintain ocean volume and continental freeboard over geologic time. Two tenths of one weight percent H2O in subducted oceanic crustal material and subsequently released to the hydrosphere from mid-ocean ridge basalt is sufficient to recycle the total ocean volume once over 4.5 billion years. It is p ...
Crustal structure of the southern margin of the African - ePIC
... [2] A number of features make southern Africa a key site for integrated geophysical and geological research on continental accretion and break-up. Bounded to the south by the Agulhas-Falkland Fracture Zone (AFFZ, Figure 1), this region represents one of the world’s best examples of a sheared contine ...
... [2] A number of features make southern Africa a key site for integrated geophysical and geological research on continental accretion and break-up. Bounded to the south by the Agulhas-Falkland Fracture Zone (AFFZ, Figure 1), this region represents one of the world’s best examples of a sheared contine ...
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... The Nakasib suture is extrapolated across the Red Sea into Saudi Arabia through ophiolitic units at Jebel Thurwah to those at Bir Umq. Closing the Red Sea, the entire Ariab-Nakasib-Bir Umq suture can be traced for approximately 700 km between its truncation to the east by the Nabitah suture in Arabi ...
... The Nakasib suture is extrapolated across the Red Sea into Saudi Arabia through ophiolitic units at Jebel Thurwah to those at Bir Umq. Closing the Red Sea, the entire Ariab-Nakasib-Bir Umq suture can be traced for approximately 700 km between its truncation to the east by the Nabitah suture in Arabi ...
P-wave crustal velocity structure in western Sichuan and eastern
... travel time of refractive and reflective phases, and the ray synthetic seismogram method[23] was used to constrain the amplitudes and improve the initial crustal velocity structure. The calculation was repeated till the final 2-D crustal model was satisfied[24]. 3.2 2-D P-wave crustal velocity struc ...
... travel time of refractive and reflective phases, and the ray synthetic seismogram method[23] was used to constrain the amplitudes and improve the initial crustal velocity structure. The calculation was repeated till the final 2-D crustal model was satisfied[24]. 3.2 2-D P-wave crustal velocity struc ...
mid-ocean ridge tectonics, volcanism and
... segments or order 1}4, and D1}D4 are ridge axis discontinuities of order 1}4. At both fast- and slow-spreading centers, first-order discontinuities are transform faults. Examples of second-order discontinuities are overlapping spreading centers (OSCs) on fast-spreading ridges and oblique shear zones ...
... segments or order 1}4, and D1}D4 are ridge axis discontinuities of order 1}4. At both fast- and slow-spreading centers, first-order discontinuities are transform faults. Examples of second-order discontinuities are overlapping spreading centers (OSCs) on fast-spreading ridges and oblique shear zones ...
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.