Anisotropy and deformation beneath the Eastern Alps
... Based on seismic observations, our planet is separated into three major zones; cores, mantle, and crust. According to rock rheology and thermal divisions the outer shell of the Earth is defined as the lithosphere. This body, consisting of the rigid upper mantle and crust, is considered to be cold an ...
... Based on seismic observations, our planet is separated into three major zones; cores, mantle, and crust. According to rock rheology and thermal divisions the outer shell of the Earth is defined as the lithosphere. This body, consisting of the rigid upper mantle and crust, is considered to be cold an ...
cntists think and work and how a hypothesis a n bt proposed
... the asthenosphere is partially molten; the melting ofjust a few percent of the asthenosphere's volume a u l d account Eor its properties and behavior. The plastic asthenosphere acts as a lubricating layer under the lithosphere, allowing the plata to move. The asthenosphere, made up of upper m d c ro ...
... the asthenosphere is partially molten; the melting ofjust a few percent of the asthenosphere's volume a u l d account Eor its properties and behavior. The plastic asthenosphere acts as a lubricating layer under the lithosphere, allowing the plata to move. The asthenosphere, made up of upper m d c ro ...
Alfred Wegener What was the Evidence?
... that would lend color to the adopted theory, whereas facts and principles opposed to it have been ignored. Thus the book leaves the impression that it has been written by an advocate rather than by an impartial ...
... that would lend color to the adopted theory, whereas facts and principles opposed to it have been ignored. Thus the book leaves the impression that it has been written by an advocate rather than by an impartial ...
Formation of plate boundaries: The role of mantle volatilization
... In this section, we treat the case where we consider that the initiation of subduction has not occurred. In uniform-viscosity convection, both convergent and divergent motions occur at the surface. This may mimic the convection that occurred during the early stages of the Earth with a weak boundary ...
... In this section, we treat the case where we consider that the initiation of subduction has not occurred. In uniform-viscosity convection, both convergent and divergent motions occur at the surface. This may mimic the convection that occurred during the early stages of the Earth with a weak boundary ...
EGU2017-5486 - CO Meeting Organizer
... rate rapidly decreasing in time. In the North Barents Basin intense subsidence continued 220 Myr since the Late Devonian and until the Late Jurassic. Moreover, about two thirds of the subsidence took place since the beginning of the Triassic while subsidence of oceanic crust would have already ended ...
... rate rapidly decreasing in time. In the North Barents Basin intense subsidence continued 220 Myr since the Late Devonian and until the Late Jurassic. Moreover, about two thirds of the subsidence took place since the beginning of the Triassic while subsidence of oceanic crust would have already ended ...
Mantle flow through the Northern Cordilleran slab window revealed
... composition of the underlying magma sources, from slab-metasomatized mantle in the Paleogene to anhydrous asthenosphere or veined lithospheric mantle in the Neogene (Carignan et al., 1994; Edwards and Russell, 2000). This wholesale displacement of arc-type mantle is herein viewed as a passive respon ...
... composition of the underlying magma sources, from slab-metasomatized mantle in the Paleogene to anhydrous asthenosphere or veined lithospheric mantle in the Neogene (Carignan et al., 1994; Edwards and Russell, 2000). This wholesale displacement of arc-type mantle is herein viewed as a passive respon ...
Mantle flow geometry from ridge to trench beneath the Gorda–Juan
... to the north. The splitting geometry on Gorda does not suggest major contributions from motion of the plate itself or rollback of the trench, which operates at less than half the speed of the Pacific Plate. The uniform, subduction-parallel splitting pattern seen on the North American Plate east of t ...
... to the north. The splitting geometry on Gorda does not suggest major contributions from motion of the plate itself or rollback of the trench, which operates at less than half the speed of the Pacific Plate. The uniform, subduction-parallel splitting pattern seen on the North American Plate east of t ...
gge_orals_nov8_2006 - Department of Earth and Planetary
... and mantle, discoveries over the last few decades have cast doubt on Bullen’s simplistic D” layer. Seismic tomography has shown that slabs penetrate into the lower mantle and may descend to the lowermost mantle before being assimilated into the surrounding perovskite and magnesio-wüstite [Grand et ...
... and mantle, discoveries over the last few decades have cast doubt on Bullen’s simplistic D” layer. Seismic tomography has shown that slabs penetrate into the lower mantle and may descend to the lowermost mantle before being assimilated into the surrounding perovskite and magnesio-wüstite [Grand et ...
Data Do Not Speak - The Story Behind The Science
... To resolve this problem, Runcorn studied rocks in North America. The data he collected could be interpreted to mean that the pole had moved. However, the path of the pole based on rocks from North America was different than the path derived from rocks in Europe. The 'mobilist' view that the continen ...
... To resolve this problem, Runcorn studied rocks in North America. The data he collected could be interpreted to mean that the pole had moved. However, the path of the pole based on rocks from North America was different than the path derived from rocks in Europe. The 'mobilist' view that the continen ...
Why did not the Ontong Java Plateau form subaerially?
... (owing to thick crust), this geotherm would put the plateau surface right on sea level. Note that, because of latent heat of fusion consumed by partial melting, actual geotherm expected for adiabatically upwelling mantle is slightly lower than geotherm C. However, latent heat of solidification is in ...
... (owing to thick crust), this geotherm would put the plateau surface right on sea level. Note that, because of latent heat of fusion consumed by partial melting, actual geotherm expected for adiabatically upwelling mantle is slightly lower than geotherm C. However, latent heat of solidification is in ...
The Mid-continent Rift
... Copper Deposits in the Duluth Complex • mantle plumes rich in magnesium, chromium, copper, nickel, platinum, and relatively low in sulfur. • copper-bearing minerals are generally sulfides • when mafic rocks, such as the Duluth Gabbro, are intruded into crustal rocks, sulfur from the crustal rocks c ...
... Copper Deposits in the Duluth Complex • mantle plumes rich in magnesium, chromium, copper, nickel, platinum, and relatively low in sulfur. • copper-bearing minerals are generally sulfides • when mafic rocks, such as the Duluth Gabbro, are intruded into crustal rocks, sulfur from the crustal rocks c ...
Paleozoic large igneous provinces of Northern Eurasia: Correlation
... Enormous lava eruptions formed large igneous provinces (LIPs) with millions of cubic kilometers emplaced in relatively short time intervals. Such magmatic events have been most likely initiated by the uplift of hot material from the core–mantle boundary and occurred several times during the Cenozoic ...
... Enormous lava eruptions formed large igneous provinces (LIPs) with millions of cubic kilometers emplaced in relatively short time intervals. Such magmatic events have been most likely initiated by the uplift of hot material from the core–mantle boundary and occurred several times during the Cenozoic ...
Igneous Extrusion, Intrusion and Underplating on the North Atlantic
... Breakup of the northern North Atlantic in the early Tertiary was accompanied by widespread and massive magmatism. The history of rifting and magmatism is intimately related, and provides a challenge both to imaging the structure using geophysical methods, and to modelling the subsidence and developm ...
... Breakup of the northern North Atlantic in the early Tertiary was accompanied by widespread and massive magmatism. The history of rifting and magmatism is intimately related, and provides a challenge both to imaging the structure using geophysical methods, and to modelling the subsidence and developm ...
lecture_2_earth_structure
... The respective mean heat flows of continental and oceanic crust are 70.9 and 105.4 mW/m2. Based on this mean continental crust heat flow value, the ground beneath our feet is releasing Earth's internal heat at a rate equivalent to 709 100-watt lightbulbs per square kilometer. While the total interna ...
... The respective mean heat flows of continental and oceanic crust are 70.9 and 105.4 mW/m2. Based on this mean continental crust heat flow value, the ground beneath our feet is releasing Earth's internal heat at a rate equivalent to 709 100-watt lightbulbs per square kilometer. While the total interna ...
The Westward Drift of the Lithosphere: A rotational drag?
... on the lithosphere that opposes to direction of mantle flow. This force can be exerted either by the lithosphere itself (e.g., slab pull or ridge push), or by an external force such as tidal drag. Slab pull is frequently invoked (e.g., Anderson, 2001; Conrad and Lithgow-Bertelloni, 2003) and is not ...
... on the lithosphere that opposes to direction of mantle flow. This force can be exerted either by the lithosphere itself (e.g., slab pull or ridge push), or by an external force such as tidal drag. Slab pull is frequently invoked (e.g., Anderson, 2001; Conrad and Lithgow-Bertelloni, 2003) and is not ...
Imag(in)ing the continental lithosphere
... 1995), although most tomographic images of the craton show high velocity roots extending to at least 200 km depth, and in some cases to depths greater than 300 km (e.g., Grand, 1994; Van der Lee and Nolet, 1997). Since body wave tomographic images smear anomalies along ray paths and the angular band ...
... 1995), although most tomographic images of the craton show high velocity roots extending to at least 200 km depth, and in some cases to depths greater than 300 km (e.g., Grand, 1994; Van der Lee and Nolet, 1997). Since body wave tomographic images smear anomalies along ray paths and the angular band ...
L01 - D4 - Teacher - Inside the Earth
... igneous (once molten) and sedimentary rocks (made by weathering / erosion and compression). The temperature can be as hot as 6000C. The crust itself is a relatively thin solid layer and is in two categories: continental and oceanic. Continental Crust (mainly Granite – density ~ 2.7 g/cm3) The cont ...
... igneous (once molten) and sedimentary rocks (made by weathering / erosion and compression). The temperature can be as hot as 6000C. The crust itself is a relatively thin solid layer and is in two categories: continental and oceanic. Continental Crust (mainly Granite – density ~ 2.7 g/cm3) The cont ...
Stress-dependent power-law flow in the upper mantle following the
... The viscoelastic power-law model works well to explain cumulative far-field displacements (Fig. 1) and far-field time-series (Fig. 2). However, this model underpredicts many of the near-field observations of cumulative displacement (Fig. 1) and near-field timeseries (Fig. 5). The underprediction of ...
... The viscoelastic power-law model works well to explain cumulative far-field displacements (Fig. 1) and far-field time-series (Fig. 2). However, this model underpredicts many of the near-field observations of cumulative displacement (Fig. 1) and near-field timeseries (Fig. 5). The underprediction of ...
Forum Reply
... area aged 1–65 m.y. of 269 × 106 km2 (Fig. 1B), as compared to 251 × 106 km2 of that by Müller et al. (2013) (Fig. 1C) and 253 × 106 km2 of our most recent reconstruction (Fig. 1D). The reconstructions reflect the stepwise inclusion of more complex mid-ocean ridge systems, modelling the breakup of t ...
... area aged 1–65 m.y. of 269 × 106 km2 (Fig. 1B), as compared to 251 × 106 km2 of that by Müller et al. (2013) (Fig. 1C) and 253 × 106 km2 of our most recent reconstruction (Fig. 1D). The reconstructions reflect the stepwise inclusion of more complex mid-ocean ridge systems, modelling the breakup of t ...
chapter 3 – answers to questions in text
... 12. The average rate of movement and relative motion of plates can be calculated in several ways. The results of these different methods all agree and indicate that the plates move at different average velocities. Absolute motion of plates can be determined by the movement of plates over hot spots. ...
... 12. The average rate of movement and relative motion of plates can be calculated in several ways. The results of these different methods all agree and indicate that the plates move at different average velocities. Absolute motion of plates can be determined by the movement of plates over hot spots. ...
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.