Graham Cracker Model of Plate Tectonics
... Graham Cracker Model of Plate Tectonics Background The Theory of Plate Tectonics states that the crust of the Earth is composed of seven major plates and numerous smaller plates. These plates “ride” on the hot plastic upper mantle known as the asthenosphere. This theory also says that most of these ...
... Graham Cracker Model of Plate Tectonics Background The Theory of Plate Tectonics states that the crust of the Earth is composed of seven major plates and numerous smaller plates. These plates “ride” on the hot plastic upper mantle known as the asthenosphere. This theory also says that most of these ...
Structure of the Lithosphere and the Sedimentary Record: Where do
... Embayment is quite different from N.J. and requires several tectonic events, including a long-term subsidence event in the mid to Late Miocene. The center of the Eocene impact crater is showing the opposite sense of motion, suggesting an in-plane stress event. Besides the subducted Farallon slab are ...
... Embayment is quite different from N.J. and requires several tectonic events, including a long-term subsidence event in the mid to Late Miocene. The center of the Eocene impact crater is showing the opposite sense of motion, suggesting an in-plane stress event. Besides the subducted Farallon slab are ...
Convergent plate boundaries
... Focus Question 5.6 • What are the characteristics of each of the three types of convergent boundaries? – Oceanic-continental collisions result in subduction zones, deep ocean trenches, and continental volcanic ...
... Focus Question 5.6 • What are the characteristics of each of the three types of convergent boundaries? – Oceanic-continental collisions result in subduction zones, deep ocean trenches, and continental volcanic ...
1. Introduction, Objectives, and Principal Results, Leg 112, Peru
... Basin, included verification that continental crust extends this far seaward with considerable subsidence. We included this objective with those of a site across the tectonic boundary separating the two types of crust. The objectives at Site 685, just below the midslope terrace, included verifying o ...
... Basin, included verification that continental crust extends this far seaward with considerable subsidence. We included this objective with those of a site across the tectonic boundary separating the two types of crust. The objectives at Site 685, just below the midslope terrace, included verifying o ...
Seismic evidence for convection-driven motion of the North
... Since the discovery of plate tectonics, the relative importance of driving forces of plate motion has been debated1,2. Resolution of this issue has been hindered by uncertainties in estimates of basal traction, which controls the coupling between lithospheric plates and underlying mantle convection2 ...
... Since the discovery of plate tectonics, the relative importance of driving forces of plate motion has been debated1,2. Resolution of this issue has been hindered by uncertainties in estimates of basal traction, which controls the coupling between lithospheric plates and underlying mantle convection2 ...
Sea-floor spreading and deformation processes in the South Atlantic
... fracture zone or flow line. The starved nature of the flow line and the differing age of the oceanic crust across it generates a distinct bathymetric and gravity feature (Figure 2) that can be traced for large distances away from the ridge axis and preserves evidence of former plate tectonic process ...
... fracture zone or flow line. The starved nature of the flow line and the differing age of the oceanic crust across it generates a distinct bathymetric and gravity feature (Figure 2) that can be traced for large distances away from the ridge axis and preserves evidence of former plate tectonic process ...
Plate Tectonics
... The uppermost mantle and crust can be subdivided vertically into two layers with contrasting mechanical (physical) properties. The outer layer, the lithosphere, is composed of the crust and uppermost mantle and forms a rigid outer shell down to a depth of approximately 100 km (63 miles). The underly ...
... The uppermost mantle and crust can be subdivided vertically into two layers with contrasting mechanical (physical) properties. The outer layer, the lithosphere, is composed of the crust and uppermost mantle and forms a rigid outer shell down to a depth of approximately 100 km (63 miles). The underly ...
Continental Drift - Pearson Higher Education
... 192 Unit Three Forces Within ill California eventually slide into the ocean as some predict? Have continents really drifted apart over the centuries? Answers to these questions and many others that have intrigued geologists for decades are now being provided by an exciting theory on large-scale mov ...
... 192 Unit Three Forces Within ill California eventually slide into the ocean as some predict? Have continents really drifted apart over the centuries? Answers to these questions and many others that have intrigued geologists for decades are now being provided by an exciting theory on large-scale mov ...
A Review of the Role of Subduction Dynamics for Regional and
... explained by fluid slabs that are ~250–500 times stiffer than the upper mantle. Slab width and, more importantly, rheology determine the role of viscous bending, poloidalsinking flow and toroidal-rollback stirring, and interactions of the slab with the higher viscosity lower mantle. Several of these ...
... explained by fluid slabs that are ~250–500 times stiffer than the upper mantle. Slab width and, more importantly, rheology determine the role of viscous bending, poloidalsinking flow and toroidal-rollback stirring, and interactions of the slab with the higher viscosity lower mantle. Several of these ...
Depleted lithosphere, cold, trapped asthenosphere, and frozen melt
... Received 22 July 2005; received in revised form 2 February 2006; accepted 6 February 2006 Available online 19 April 2006 Editor: K. Farley ...
... Received 22 July 2005; received in revised form 2 February 2006; accepted 6 February 2006 Available online 19 April 2006 Editor: K. Farley ...
Alpine–Himalayan orogenic belt
... were thrust northward into Tibet, and two huge thrust faults carried Paleozoic and Mesozoic rocks of Asian origin onto the Indian plate ...
... were thrust northward into Tibet, and two huge thrust faults carried Paleozoic and Mesozoic rocks of Asian origin onto the Indian plate ...
1 Ocean Islands and Plume Magmatism
... features is a seismically fast slab-like anomaly that extends from the surface beneath the Continental US well throughout the whole mantle. This is thought to be the image of the subducted Farallon plate. ...
... features is a seismically fast slab-like anomaly that extends from the surface beneath the Continental US well throughout the whole mantle. This is thought to be the image of the subducted Farallon plate. ...
Chapter 16: Geology of the Ocean
... new ocean floor. This process, which has been occurring for many millions of years, is recorded in the symmetrical, parallel bands of basalt (the volcanic rock that makes up the ocean floor) that spread out along either side of the ridge. The spreading apart of the Atlantic seafloor is an ongoing pr ...
... new ocean floor. This process, which has been occurring for many millions of years, is recorded in the symmetrical, parallel bands of basalt (the volcanic rock that makes up the ocean floor) that spread out along either side of the ridge. The spreading apart of the Atlantic seafloor is an ongoing pr ...
Do deep mantle plumes exist?
... (Anderson 2003 (2)). Controversy exists as to whether the upper and lower mantles form one single or two separate convections cells, and whether material can be positively identified as rising up from the lower mantle through the Transition Zone (Hofmeister & Criss 2003). The deepest source recorded ...
... (Anderson 2003 (2)). Controversy exists as to whether the upper and lower mantles form one single or two separate convections cells, and whether material can be positively identified as rising up from the lower mantle through the Transition Zone (Hofmeister & Criss 2003). The deepest source recorded ...
Dehydration of serpentinized slab mantle: Seismic evidence from southwest Japan
... mantle have also been detected. This indicates that the PHS mantle beneath these areas is also hydrated, which may have resulted from subduction of the serpentine stable in the Izu-Bonin back-arc area. Aqueous fluids released from the serpentinized mantle beneath Kii Peninsula may have initiated par ...
... mantle have also been detected. This indicates that the PHS mantle beneath these areas is also hydrated, which may have resulted from subduction of the serpentine stable in the Izu-Bonin back-arc area. Aqueous fluids released from the serpentinized mantle beneath Kii Peninsula may have initiated par ...
What is the meaning of ophiolites? - Creation Ministries International
... mystified: ‘The emplacement of oceanic lithosphere [crust and upper mantle] onto continents remains one of the great mysteries of plate tectonics—how does ophiolitic material with a density of 3.0–3.3 g/cm3 rise from its natural depths of ≥2.5 km beneath the ocean surface to elevations more than 1 k ...
... mystified: ‘The emplacement of oceanic lithosphere [crust and upper mantle] onto continents remains one of the great mysteries of plate tectonics—how does ophiolitic material with a density of 3.0–3.3 g/cm3 rise from its natural depths of ≥2.5 km beneath the ocean surface to elevations more than 1 k ...
References
... planes [19,25], and not by intergranular flow. The migration may be facilitated because these rocks were probably undergoing deformation at the same time. The fluids are emitted cold or lukewarm, but were generated at temperatures well above 10000C, so they must have given off their heat content to ...
... planes [19,25], and not by intergranular flow. The migration may be facilitated because these rocks were probably undergoing deformation at the same time. The fluids are emitted cold or lukewarm, but were generated at temperatures well above 10000C, so they must have given off their heat content to ...
Mann et al in prep
... constraints as possible. The reconstructions show that some of the tectonic and geochemical complexities of the CAVA and CAVF may be related to structures and crustal variations in the upper plate. Some important tectonic elements of the CAVA that attest to its mobility, highlighted in reconstructio ...
... constraints as possible. The reconstructions show that some of the tectonic and geochemical complexities of the CAVA and CAVF may be related to structures and crustal variations in the upper plate. Some important tectonic elements of the CAVA that attest to its mobility, highlighted in reconstructio ...
The Fate of Subducted Oceanic Crust and the Sources of Intraplate
... should also be seen in intraplate basalts. The general lack of such a signature suggests Kenrichment is related to a process which does not fractionate Lu from Hf, such as the formation of volatile-bearing phases such as amphibole and phlogopite in the mantle wedge ...
... should also be seen in intraplate basalts. The general lack of such a signature suggests Kenrichment is related to a process which does not fractionate Lu from Hf, such as the formation of volatile-bearing phases such as amphibole and phlogopite in the mantle wedge ...
Thermal structure and intermediate-depth seismicity in the Tohoku
... ignore thermal buoyancy, the thermal expansivity is effectively zero. The full details on the governing equations are provided in Syracuse et al. (2010). The wedge fluid is entrained by the subduction of the slab and the resulting corner flow brings high temperatures to the slab surface (van Keken, ...
... ignore thermal buoyancy, the thermal expansivity is effectively zero. The full details on the governing equations are provided in Syracuse et al. (2010). The wedge fluid is entrained by the subduction of the slab and the resulting corner flow brings high temperatures to the slab surface (van Keken, ...
Plate tectonics: teacher notes and student activities (AGSO Record
... The boundary of the two plates is marked at the surface by a deep trench. These trenches form the deepest parts of the oceans. Sediments are deposited in these trenches and as the plates move the sediment is scraped off and added to the continental plate. An example of this type of boundary occurs b ...
... The boundary of the two plates is marked at the surface by a deep trench. These trenches form the deepest parts of the oceans. Sediments are deposited in these trenches and as the plates move the sediment is scraped off and added to the continental plate. An example of this type of boundary occurs b ...
Sample
... This type of convergence produces the deepest trenches. Similar to oceanic–continental convergence, the subducting oceanic plate becomes heated, releasing superheated gases, and partially melting the overlying mantle. This buoyant molten material rises to the surface and fuels active volcanoes, whic ...
... This type of convergence produces the deepest trenches. Similar to oceanic–continental convergence, the subducting oceanic plate becomes heated, releasing superheated gases, and partially melting the overlying mantle. This buoyant molten material rises to the surface and fuels active volcanoes, whic ...
Sample
... This type of convergence produces the deepest trenches. Similar to oceanic–continental convergence, the subducting oceanic plate becomes heated, releasing superheated gases, and partially melting the overlying mantle. This buoyant molten material rises to the surface and fuels active volcanoes, whic ...
... This type of convergence produces the deepest trenches. Similar to oceanic–continental convergence, the subducting oceanic plate becomes heated, releasing superheated gases, and partially melting the overlying mantle. This buoyant molten material rises to the surface and fuels active volcanoes, whic ...
Investigating the lithospheric velocity structures beneath the Taiwan
... around latitude 23.2°N at the depth of 60 km, which can be shown more clearly in the profile AA′ to CC′ with a retreat of Moho interface to the west (top of MP denoted by dotted line). To the south, the high-Vp slab image is narrow and striking NNW-SSE, whereas to the north, the slab turns nearly N-S ...
... around latitude 23.2°N at the depth of 60 km, which can be shown more clearly in the profile AA′ to CC′ with a retreat of Moho interface to the west (top of MP denoted by dotted line). To the south, the high-Vp slab image is narrow and striking NNW-SSE, whereas to the north, the slab turns nearly N-S ...
Chapter 4 Section 2 The Theory of Plate Tectonics
... • Lithosphere- the solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle • Asthenosphere-the solid, plastic layer of the mantle beneath the lithosphere; made of mantle rock that flows very slowly, which allows tectonic plates to move on top of it Chapter menu ...
... • Lithosphere- the solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle • Asthenosphere-the solid, plastic layer of the mantle beneath the lithosphere; made of mantle rock that flows very slowly, which allows tectonic plates to move on top of it Chapter menu ...
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.