A trace element perspective on the source of ocean island basalts
... basalts. OIB are particularly variable in composition such that several isotopically distinct mantle source end-members (e.g., “DMM”, “EM1”, “EM2”, “HIMU”, “FOZO”, “C”) have been proposed to explain the variability (e.g., White, 1985; Zindler and Hart, 1986; Hart et al., 1992; Hanan and Graham, 1996 ...
... basalts. OIB are particularly variable in composition such that several isotopically distinct mantle source end-members (e.g., “DMM”, “EM1”, “EM2”, “HIMU”, “FOZO”, “C”) have been proposed to explain the variability (e.g., White, 1985; Zindler and Hart, 1986; Hart et al., 1992; Hanan and Graham, 1996 ...
Role of the subducted slab, mantle wedge and
... granulites without garnet, consistent with a relatively thin crust. The Chile Rise was subducted below the Austral Andes during the late Miocene, resulting in the development of a "slab-window" and extensive basaltic plateau volcanism in southern Patagonia prior to the reinitiation of subduction and ...
... granulites without garnet, consistent with a relatively thin crust. The Chile Rise was subducted below the Austral Andes during the late Miocene, resulting in the development of a "slab-window" and extensive basaltic plateau volcanism in southern Patagonia prior to the reinitiation of subduction and ...
Simple Kinematics of Subduction Zones
... Andes, which may or may not evolve to continentcontinent collision such as the Alps or Himalayas (Ernst, 2005). Along W-directed subduction zones, there also are variable compositions of the lower plate (both oceanic and continental lithosphere, e.g., Marianas and Apennines, Banda arc) and variable ...
... Andes, which may or may not evolve to continentcontinent collision such as the Alps or Himalayas (Ernst, 2005). Along W-directed subduction zones, there also are variable compositions of the lower plate (both oceanic and continental lithosphere, e.g., Marianas and Apennines, Banda arc) and variable ...
Lithospheric Removal as aTrigger for Flood
... affected the Quere¤taro area in the central portion of the arc at 8^6 Ma (Fig. 2b; Pasquare' et al., 1991; Valde¤zMoreno et al., 1998; Aguirre-D|¤ az & Lo¤pez-Mart|¤ nez, 2001), and the eastern TMVB between the Late Miocene and Early Pliocene (7·5^3·5 Ma; Ferrari et al., 2005b; Fig. 2b). It has be ...
... affected the Quere¤taro area in the central portion of the arc at 8^6 Ma (Fig. 2b; Pasquare' et al., 1991; Valde¤zMoreno et al., 1998; Aguirre-D|¤ az & Lo¤pez-Mart|¤ nez, 2001), and the eastern TMVB between the Late Miocene and Early Pliocene (7·5^3·5 Ma; Ferrari et al., 2005b; Fig. 2b). It has be ...
alps vs apennines - Dipartimento di Scienze della Terra
... down since the late Pliocene, but it locally shows to be still active as evidenced by compressional seismicity in frontal areas and uplift of the belt. The Alps have a conjugate antithetic retrobelt, i.e., the Southern Alps, which started to develop since the early stages of the subduction, like it ...
... down since the late Pliocene, but it locally shows to be still active as evidenced by compressional seismicity in frontal areas and uplift of the belt. The Alps have a conjugate antithetic retrobelt, i.e., the Southern Alps, which started to develop since the early stages of the subduction, like it ...
Continental arc–island arc fluctuations, growth of crustal carbonates
... concentrations of atmospheric CO2 . Hypotheses for the elevated CO2 concentrations invoke an increase in volcanic CO2 production due to higher oceanic crust production rates, higher frequency of large igneous provinces, or increases in pelagic carbonate deposition, the last leading to enhanced carbo ...
... concentrations of atmospheric CO2 . Hypotheses for the elevated CO2 concentrations invoke an increase in volcanic CO2 production due to higher oceanic crust production rates, higher frequency of large igneous provinces, or increases in pelagic carbonate deposition, the last leading to enhanced carbo ...
Uplift movements in New Caledonia-Loyalty islands area and their
... The comparison of amplitudes and speeds of the uplift movements between the different dated levels reveals two separate movements. On the one hand a slow regional uplift movement for Loyalty Islands, Isle of Pines and probably the south of New Caledonia and on the other hand a rapid positive movemen ...
... The comparison of amplitudes and speeds of the uplift movements between the different dated levels reveals two separate movements. On the one hand a slow regional uplift movement for Loyalty Islands, Isle of Pines and probably the south of New Caledonia and on the other hand a rapid positive movemen ...
and island arcs
... • SVZ - Accreted Mesozoic and Cenozoic oceanic crust and island arcs,, 30-45 km thick These are separated by inactive gaps. This belt of igneous rocks developed over last 500 Ma and is commonly termed an Andeantype margin. Image source: Winter, 2001 ...
... • SVZ - Accreted Mesozoic and Cenozoic oceanic crust and island arcs,, 30-45 km thick These are separated by inactive gaps. This belt of igneous rocks developed over last 500 Ma and is commonly termed an Andeantype margin. Image source: Winter, 2001 ...
Seismic view on the svalbard passive continental margin
... respectively. The oceanic crust is generally similar in terms of thickness along all the profiles studied here but it is composed of more layers in those three southern profiles, where the opening of Northern Atlantic happened earlier. Differences in crustal thickness are the result of different spr ...
... respectively. The oceanic crust is generally similar in terms of thickness along all the profiles studied here but it is composed of more layers in those three southern profiles, where the opening of Northern Atlantic happened earlier. Differences in crustal thickness are the result of different spr ...
CHAPTER 3: Geophysics and lithospheric structure of the Arabian
... effectively found at the magnetic pole. The result is to center the magnetic anomaly directly over the causative body, and the benefit for the interpreter is that the shape and position of the anomaly spatially coincide with the underlying magnetic rock, whether it be a pluton, dike, volcanic format ...
... effectively found at the magnetic pole. The result is to center the magnetic anomaly directly over the causative body, and the benefit for the interpreter is that the shape and position of the anomaly spatially coincide with the underlying magnetic rock, whether it be a pluton, dike, volcanic format ...
Cape Verde hotspot from the upper crust to the top of the lower mantle
... Verde swell. Davaille et al. (2005) relate it to a large-scale velocity anomaly in the lower mantle but note the lack of reliable images of the mantle between 400-km and 1000-km depths. Seismic tomography data suggest that the origin of the Cape Verde plume is near the core– mantle boundary (Montell ...
... Verde swell. Davaille et al. (2005) relate it to a large-scale velocity anomaly in the lower mantle but note the lack of reliable images of the mantle between 400-km and 1000-km depths. Seismic tomography data suggest that the origin of the Cape Verde plume is near the core– mantle boundary (Montell ...
A Primer
... makes the thermal boundary layer currents flow laterally? While it may seem intuitively obvious that boundary layer fluid feeding a vertical current must flow horizontally (such as fluid going toward a drain), the forces behind these currents are of significance in regard to plate forces. It should ...
... makes the thermal boundary layer currents flow laterally? While it may seem intuitively obvious that boundary layer fluid feeding a vertical current must flow horizontally (such as fluid going toward a drain), the forces behind these currents are of significance in regard to plate forces. It should ...
Chapter 4: Igneous Rocks: Product of Earth`s Internal Fire
... that erupt basaltic magma also occur on both oceanic and continental crust. —The source of basaltic magma, therefore, must be the mantle. —Everywhere along the midocean ridges, volcanoes erupt basaltic magma. —Some large basaltic volcanoes are not located along midocean ridges. The Hawaiian volcanic ...
... that erupt basaltic magma also occur on both oceanic and continental crust. —The source of basaltic magma, therefore, must be the mantle. —Everywhere along the midocean ridges, volcanoes erupt basaltic magma. —Some large basaltic volcanoes are not located along midocean ridges. The Hawaiian volcanic ...
The Relation Between Mantle Dynamics and Plate Tectonics: A Primer
... makes the thermal boundary layer currents flow laterally? While it may seem intuitively obvious that boundary layer fluid feeding a vertical current must flow horizontally (such as fluid going toward a drain), the forces behind these currents are of significance in regard to plate forces. It should ...
... makes the thermal boundary layer currents flow laterally? While it may seem intuitively obvious that boundary layer fluid feeding a vertical current must flow horizontally (such as fluid going toward a drain), the forces behind these currents are of significance in regard to plate forces. It should ...
The Making of the Japan Sea and the Japanese Mountains
... There is little more dramatic than the opening of a back-arc basin sea behind a volcanic arc. An extensional back-arc basin forms by the pushing out of a section of continental coast into an offshore arc, with the new basin behind the arc filling with sea water and often having a floor built of ocea ...
... There is little more dramatic than the opening of a back-arc basin sea behind a volcanic arc. An extensional back-arc basin forms by the pushing out of a section of continental coast into an offshore arc, with the new basin behind the arc filling with sea water and often having a floor built of ocea ...
Dynamic topography above retreating subduction zones
... to map a residual topography as in the Scotia Sea. However, the depth of the backarc spreading ridge still contains information about possible dynamic topography. As in the Scotia Sea, the ridge axis deepens away from the edges of the basin by more than 1000 m (Fig. 3B), similarly consistent with th ...
... to map a residual topography as in the Scotia Sea. However, the depth of the backarc spreading ridge still contains information about possible dynamic topography. As in the Scotia Sea, the ridge axis deepens away from the edges of the basin by more than 1000 m (Fig. 3B), similarly consistent with th ...
Origin of the concentrated deformation zone in the Japanese Islands... accumulation process of intraplate earthquakes
... quantitatively, by 3 kinematic models named as the detachment model (Hirahara et al., 1998); the collision model (Shimazaki and Zhao, 2000; Heki and Miyazaki, 2001; Miyazaki and Heki, 2001); and the back-slip model (Mazzotti et al., 2000). Iio et al. (2002) examined those models and concluded that t ...
... quantitatively, by 3 kinematic models named as the detachment model (Hirahara et al., 1998); the collision model (Shimazaki and Zhao, 2000; Heki and Miyazaki, 2001; Miyazaki and Heki, 2001); and the back-slip model (Mazzotti et al., 2000). Iio et al. (2002) examined those models and concluded that t ...
Upper mantle structure of eastern Asia from multimode surface
... centroid moment tensor catalog during the period 1977– 2002; however, because of the great expansion of the Global Digital Seismograph Network in the mid-1990s, most of the data are from the period since 1994. [10] Since the waveforms are automatically fit for each seismogram, the two most important ...
... centroid moment tensor catalog during the period 1977– 2002; however, because of the great expansion of the Global Digital Seismograph Network in the mid-1990s, most of the data are from the period since 1994. [10] Since the waveforms are automatically fit for each seismogram, the two most important ...
Earth as a Planet
... Galileo’s discoveries caused many more people to accept the heliocentric model of the universe, although Galileo himself was found guilty of heresy. The shift from an Earth-centered view to a Sun-centered view of the universe is referred to as the Copernican Revolution. In their elliptical orbits, e ...
... Galileo’s discoveries caused many more people to accept the heliocentric model of the universe, although Galileo himself was found guilty of heresy. The shift from an Earth-centered view to a Sun-centered view of the universe is referred to as the Copernican Revolution. In their elliptical orbits, e ...
Controls on back-arc basin formation
... while it cools and contracts and becomes less buoyant. Relationships between age and thickness [Heestand and Crough, 1981; Stein and Stein, 1996], age and trench depth [Grellet and Dubois, 1982], age and heat flow [Sclater, 1972; Stein and Stein, 1992] and age and depth of ...
... while it cools and contracts and becomes less buoyant. Relationships between age and thickness [Heestand and Crough, 1981; Stein and Stein, 1996], age and trench depth [Grellet and Dubois, 1982], age and heat flow [Sclater, 1972; Stein and Stein, 1992] and age and depth of ...
Behaviour of high field strength elements in subduction zones
... assess differences in HFSE mobility during slab melting and dehydration and (2) to identify different source mineralogies. The Kamchatka –western Aleutian arcs are ideally suited for this purpose because (1) they display compositional end members for both slab fluid-and slab melt-dominated regimes i ...
... assess differences in HFSE mobility during slab melting and dehydration and (2) to identify different source mineralogies. The Kamchatka –western Aleutian arcs are ideally suited for this purpose because (1) they display compositional end members for both slab fluid-and slab melt-dominated regimes i ...
Text
... The equation σ = ρgh, gives us the normal stress, where: σ = normal stress, ρ = density, g = gravity and h = height. As the height of the sand increases so does the normal stress and as the normal stress increases the sand is no longer capable of holding that load, so the accretionary wedge faults. ...
... The equation σ = ρgh, gives us the normal stress, where: σ = normal stress, ρ = density, g = gravity and h = height. As the height of the sand increases so does the normal stress and as the normal stress increases the sand is no longer capable of holding that load, so the accretionary wedge faults. ...
Kinematic Evolution of the Gulf of Mexico and Caribbean James
... al., 1998). Finally, we must remove oceanic and island arc terranes accreted to the continental margins (e.g., parts of Baja California, Amaime, Ruma and Villa de Cura terranes of Colombia and Venezuela, Piñon Terrane of Ecuador, etc). A consensus of opinion is emerging for the earlier (Jurassic) a ...
... al., 1998). Finally, we must remove oceanic and island arc terranes accreted to the continental margins (e.g., parts of Baja California, Amaime, Ruma and Villa de Cura terranes of Colombia and Venezuela, Piñon Terrane of Ecuador, etc). A consensus of opinion is emerging for the earlier (Jurassic) a ...
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.