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 ...
Ocean Model Pre
... one half a mile to one mile high and 3,000 miles long. It is as sharp and jagged, as if it had been formed yesterday. In spite of its appearances, the seafloor is 70 million years old in places and almost unchanged. 6. How are the submarine ridges and other features preserved unchanged? ____________ ...
... one half a mile to one mile high and 3,000 miles long. It is as sharp and jagged, as if it had been formed yesterday. In spite of its appearances, the seafloor is 70 million years old in places and almost unchanged. 6. How are the submarine ridges and other features preserved unchanged? ____________ ...
Recall Hypsometric Curve?
... – Includes crust and rigid upper mantle – This is the rigid plate in plate tectonics – Base is defined by 1200º 1200ºC boundary ...
... – Includes crust and rigid upper mantle – This is the rigid plate in plate tectonics – Base is defined by 1200º 1200ºC boundary ...
Sedimentary cover of the Ankara Mélange: role of the Upper
... overthrusting the western basin margin, as part of major thrust faults affecting the area. However, new mapping shows that convergence increases northwards, with only high-angle reverse faulting of Palaeocene age being observed in the south. Although the basin fill is commonly reverse-faulted and lo ...
... overthrusting the western basin margin, as part of major thrust faults affecting the area. However, new mapping shows that convergence increases northwards, with only high-angle reverse faulting of Palaeocene age being observed in the south. Although the basin fill is commonly reverse-faulted and lo ...
Subduction zones: observations and
... temperature dependence of olivine, one would conclude that the core of a subducting slab is at least 10,000 times more viscous than ambient mantle; however, there are a number of complementary but independent observations that suggest that slabs are much weaker than this. Slabs undergo significant d ...
... temperature dependence of olivine, one would conclude that the core of a subducting slab is at least 10,000 times more viscous than ambient mantle; however, there are a number of complementary but independent observations that suggest that slabs are much weaker than this. Slabs undergo significant d ...
Plate Tectonics
... long rift valleys where volcanic eruptions and earthquakes occur from time to time. • In the Atlantic, the Pacific, and in other oceans around the world, a system of ridges, called the mid-ocean ridges, is present. ...
... long rift valleys where volcanic eruptions and earthquakes occur from time to time. • In the Atlantic, the Pacific, and in other oceans around the world, a system of ridges, called the mid-ocean ridges, is present. ...
Geophysical Journal International
... Key words: Mantle processes; Phase transitions; North America. ...
... Key words: Mantle processes; Phase transitions; North America. ...
EVIDENCE TO THE CONTRARY (CHAPTER 6)
... Convergent continental margins • The outer edge of the continental margin is defined by either: – The seaward edge of the accretionary prism – The foot of the upper plate – The foot of the inner trench wall ...
... Convergent continental margins • The outer edge of the continental margin is defined by either: – The seaward edge of the accretionary prism – The foot of the upper plate – The foot of the inner trench wall ...
evaluateessay 19.95KB 2017-03-29 12:41:56
... mountains here such as the Himalayas. The theory of plate tectonics explains that oceanic plates, because they are denser, always subduct continental plates. Here two continental plates meet – so scientists developed a theory that fold mountains were created. The two plates converge, neither subduc ...
... mountains here such as the Himalayas. The theory of plate tectonics explains that oceanic plates, because they are denser, always subduct continental plates. Here two continental plates meet – so scientists developed a theory that fold mountains were created. The two plates converge, neither subduc ...
SubFac abstract from Robert J. Stern
... retreating upper plate and an extremely old (hence dense) subducting plate results in a strongly extensional convergent plate boundary, particularly in the southern IBM where these effects are maximized. Off-ridge volcanism was common during mid- and Late Cretaceous time on the Pacific Plate now out ...
... retreating upper plate and an extremely old (hence dense) subducting plate results in a strongly extensional convergent plate boundary, particularly in the southern IBM where these effects are maximized. Off-ridge volcanism was common during mid- and Late Cretaceous time on the Pacific Plate now out ...
Geological understanding of plate tectonics
... have been proposed as possible sites of subduction initiation because these zones of weakness can be subsequently reactivated (e.g., Casey & Dewey 1984; Toth & Gurnis 1998; Gurnis et al. 2004), but again the lack of required compositional (and thermal) buoyancy contrast across these zones makes subd ...
... have been proposed as possible sites of subduction initiation because these zones of weakness can be subsequently reactivated (e.g., Casey & Dewey 1984; Toth & Gurnis 1998; Gurnis et al. 2004), but again the lack of required compositional (and thermal) buoyancy contrast across these zones makes subd ...
Depth-dependent geometry of margin-parallel strike-slip
... ABSTRACT. Based on the principle that faults develop where shear stress is maximum, we determine the depth-dependent geometry of margin-parallel strike-slip faults within oblique subduction zones. Using an elastic half-space model for the south Chile subduction zone, we show that the geometry of a m ...
... ABSTRACT. Based on the principle that faults develop where shear stress is maximum, we determine the depth-dependent geometry of margin-parallel strike-slip faults within oblique subduction zones. Using an elastic half-space model for the south Chile subduction zone, we show that the geometry of a m ...
Plate Tectonics Quiz - Mr. Long`s Classroom
... d. The continents were once attached to each America by explorers other and then drifted apart. A difference between the oceanic crust and the continental crust is that the oceanic crust is a. composed chiefly of sedimentary rocks. c. older than the continental crust. b. more dense than the continen ...
... d. The continents were once attached to each America by explorers other and then drifted apart. A difference between the oceanic crust and the continental crust is that the oceanic crust is a. composed chiefly of sedimentary rocks. c. older than the continental crust. b. more dense than the continen ...
Annenberg Learner: Plate Tectonics Web Quest Name: Blk:
... 2) Please read information on PLATE TECTONICS A) Who was Alfred Wegener? B) His theory was based upon what 3 pieces of evidence? C) What were 3 pieces of information that were published in Wegener's book? 3) "Continents On the Move" ~ please use the CHART & BULLET 2 FACTS for each time period noted. ...
... 2) Please read information on PLATE TECTONICS A) Who was Alfred Wegener? B) His theory was based upon what 3 pieces of evidence? C) What were 3 pieces of information that were published in Wegener's book? 3) "Continents On the Move" ~ please use the CHART & BULLET 2 FACTS for each time period noted. ...
Let`s think about it. If a lithospheric plate moved 5 centimeters per
... This process repeats over and over again and forms a string of islands. The first island formed in the string is made of old dormant volcanoes, while the most recent island the string probably has active volcanoes. Scientists determine the direction and speed of plate movement by measuring these isl ...
... This process repeats over and over again and forms a string of islands. The first island formed in the string is made of old dormant volcanoes, while the most recent island the string probably has active volcanoes. Scientists determine the direction and speed of plate movement by measuring these isl ...
Oceanic ridges - HCC Learning Web
... produces a continuous mountain range when the continents are positioned next to each other, as they were during the formation of Pangea. ...
... produces a continuous mountain range when the continents are positioned next to each other, as they were during the formation of Pangea. ...
Plate Tectonics: A Unifying Theory
... produces a continuous mountain range when the continents are positioned next to each other, as they were during the formation of Pangea. ...
... produces a continuous mountain range when the continents are positioned next to each other, as they were during the formation of Pangea. ...
Geodynamics
... • To determine the tectonic stress orientation different types of stress indicators are used in the World Stress Map. They are grouped into four categories: – earthquake focal mechanisms – well bore breakouts and drilling induced fractures – in-situ stress measurements (overcoring, hydraulic ...
... • To determine the tectonic stress orientation different types of stress indicators are used in the World Stress Map. They are grouped into four categories: – earthquake focal mechanisms – well bore breakouts and drilling induced fractures – in-situ stress measurements (overcoring, hydraulic ...
the origin of modern chiapanecan volcanic arc in southern mexico
... Southern Mexico is a very interesting area where the subducting Cocos slab drastically changes its geometry: from a flat slab in Central Mexico to a ~ 45° dip angle beneath Chiapas. Also, the currently active volcanic arc, the modern Chiapanecan volcanic arc, is oblique and situated far inland from ...
... Southern Mexico is a very interesting area where the subducting Cocos slab drastically changes its geometry: from a flat slab in Central Mexico to a ~ 45° dip angle beneath Chiapas. Also, the currently active volcanic arc, the modern Chiapanecan volcanic arc, is oblique and situated far inland from ...
Ch 4 PPT - Blountstown Middle School
... continental drift, which suggested that continents are in constant motion on the surface of Earth. • Wegener observed the similarities of continental coastlines now separated by oceans and how they could fit together like pieces of a puzzle. ...
... continental drift, which suggested that continents are in constant motion on the surface of Earth. • Wegener observed the similarities of continental coastlines now separated by oceans and how they could fit together like pieces of a puzzle. ...
Crustal structure of the central Sunda margin at the onset of oblique
... allows us to present a detailed model of the subduction zone where initiation of strain partitioning occurs due to the onset of oblique subduction. The dip of the subducted plate is well defined along both dip-lines and a lateral increase from 5u to 7u from beneath the outer high off Sumatra to Sund ...
... allows us to present a detailed model of the subduction zone where initiation of strain partitioning occurs due to the onset of oblique subduction. The dip of the subducted plate is well defined along both dip-lines and a lateral increase from 5u to 7u from beneath the outer high off Sumatra to Sund ...
Morphology of the distorted subducted Pacific slab beneath the
... Gorbatov and Kennett (2003) together with a new P-wave tomographic inversion were produced from the same arrival-time data. The detailed joint inversion datasets used an inversion algorithm introduced by Kennett et al. (1998) that was then adapted by Gorbatov and Kennett (2003) to include 3D ray tra ...
... Gorbatov and Kennett (2003) together with a new P-wave tomographic inversion were produced from the same arrival-time data. The detailed joint inversion datasets used an inversion algorithm introduced by Kennett et al. (1998) that was then adapted by Gorbatov and Kennett (2003) to include 3D ray tra ...
Oceanic trench
The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few mm to over ten cm per year. A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to a volcanic island arc, and about 200 km (120 mi) from a volcanic arc. Oceanic trenches typically extend 3 to 4 km (1.9 to 2.5 mi) below the level of the surrounding oceanic floor. The greatest ocean depth to be sounded is in the Challenger Deep of the Mariana Trench, at a depth of 11,034 m (36,201 ft) below sea level. Oceanic lithosphere moves into trenches at a global rate of about 3 km2/yr.