Worldwide distribution of ages of the continental lithosphere derived
... function of age. O'Reilly and Griffin (2006) showed that Archean subcrustal lithosphere is rich in MgO and has a low geotherm whereas young subcrustal lithosphere is rich in Fe and has a steep geotherm. Jordan (1975, 1981) introduced the notion of tectosphere — a deep root beneath cratons. Jordan (19 ...
... function of age. O'Reilly and Griffin (2006) showed that Archean subcrustal lithosphere is rich in MgO and has a low geotherm whereas young subcrustal lithosphere is rich in Fe and has a steep geotherm. Jordan (1975, 1981) introduced the notion of tectosphere — a deep root beneath cratons. Jordan (19 ...
Plate motions, Andean orogeny, and volcanism above the
... Nazca trench and the Andean belt. As a result, mountain belts, and more generally backarc regions (Lallemand et al., 2008), can be regarded as dynamometers: their geometry and kinematics provide a straightforward tool to measure the force balance at their location. The Andes (Fig. 1a) stand above 50 ...
... Nazca trench and the Andean belt. As a result, mountain belts, and more generally backarc regions (Lallemand et al., 2008), can be regarded as dynamometers: their geometry and kinematics provide a straightforward tool to measure the force balance at their location. The Andes (Fig. 1a) stand above 50 ...
Radiogenic isotope-3He/4He-δ18O relationships for global
... Component Samoa), these endmembers also have δ18O compositions that are elevated from the range observed for high-3He/4He samples, although there is evidence that the EM1 component at Pitcairn has a δ18O composition similar to the mean mantle (Eiler et al., 1995). The fact that high-3He/4He location ...
... Component Samoa), these endmembers also have δ18O compositions that are elevated from the range observed for high-3He/4He samples, although there is evidence that the EM1 component at Pitcairn has a δ18O composition similar to the mean mantle (Eiler et al., 1995). The fact that high-3He/4He location ...
Geo-neutrinos and Earth Models
... Models developed to explain the composition of the Earth and the abundances of the heat producing elements (i.e., K, Th and U) therein are developed from concepts that use chondritic meteorites, which are primitive undifferentiated solar system materials assembled during the initial accretion and for ...
... Models developed to explain the composition of the Earth and the abundances of the heat producing elements (i.e., K, Th and U) therein are developed from concepts that use chondritic meteorites, which are primitive undifferentiated solar system materials assembled during the initial accretion and for ...
Earthquakes - teachearthscience.org
... rocks bend and store elastic energy. Eventually the frictional resistance is overcome (exceed shear strength of rocks) and slippage occurs. The built-up strain is released and the deformed rocks "snap back." An earthquake results from vibrations as the rock snaps back into shape - elastic rebound. ...
... rocks bend and store elastic energy. Eventually the frictional resistance is overcome (exceed shear strength of rocks) and slippage occurs. The built-up strain is released and the deformed rocks "snap back." An earthquake results from vibrations as the rock snaps back into shape - elastic rebound. ...
Noble Gas Constraints on Mantle Structure and Convection
... radioactive parents U, Th, and K during partial melting? Can the noble gases be partitioned into the core? • What physical mechanism(s) control gas loss during mid ocean ridge and ocean island volcanism? Can we ‘see through’ such gas loss processes to infer the concentrations in the different mantle ...
... radioactive parents U, Th, and K during partial melting? Can the noble gases be partitioned into the core? • What physical mechanism(s) control gas loss during mid ocean ridge and ocean island volcanism? Can we ‘see through’ such gas loss processes to infer the concentrations in the different mantle ...
seismic waves - Gordon State College
... Magnetic Studies of the Ocean Floor • The seafloor holds a record of Earth’s magnetic field at the time the rocks of the seafloor cooled. • The magnetic record appears as parallel, zebra-like stripes on both sides of mid-ocean ridges. • The age of the ocean floor and the rate of seafloor spreading c ...
... Magnetic Studies of the Ocean Floor • The seafloor holds a record of Earth’s magnetic field at the time the rocks of the seafloor cooled. • The magnetic record appears as parallel, zebra-like stripes on both sides of mid-ocean ridges. • The age of the ocean floor and the rate of seafloor spreading c ...
Offshore Somalia: crustal structure and implications
... E-W, such that the MSI Block drifted due-south. The western margin of this transform movement was controlled by the N-S orientated Davie Fracture Zone to the west, whilst the Auxilliary Rescue and Salvage (ARS) Fracture Zone, Dhow Ridge and Very Large Crude Carrier (VLCC) Ridge accommodated extensio ...
... E-W, such that the MSI Block drifted due-south. The western margin of this transform movement was controlled by the N-S orientated Davie Fracture Zone to the west, whilst the Auxilliary Rescue and Salvage (ARS) Fracture Zone, Dhow Ridge and Very Large Crude Carrier (VLCC) Ridge accommodated extensio ...
Crustal thickening in an extensional regime: application to the mid
... rift axis was not located here but instead jumped westward with respect to the earlier rift axes locations. The modeling study predicts that local crustal thickening during extension can be expected when large lateral thermal variations are present in the lithosphere at the onset of extension. Negat ...
... rift axis was not located here but instead jumped westward with respect to the earlier rift axes locations. The modeling study predicts that local crustal thickening during extension can be expected when large lateral thermal variations are present in the lithosphere at the onset of extension. Negat ...
The Quest for Self-Consistent Generation of Plate Tectonics in
... lithosphere has a higher viscosity than the mantle beneath (largely because it is colder but also because cratonic regions may be depleted in water, as discussed above), and deep continental cratonic roots have a higher viscosity than sub-oceanic mantle at the same depth (e.g., 100 km), for the same ...
... lithosphere has a higher viscosity than the mantle beneath (largely because it is colder but also because cratonic regions may be depleted in water, as discussed above), and deep continental cratonic roots have a higher viscosity than sub-oceanic mantle at the same depth (e.g., 100 km), for the same ...
Chapter 4: Igneous Rocks: Product of Earth`s Internal Fire
... Earthquake forecasting is based largely on elastic rebound theory and plate tectonics. The elastic rebound theory suggests that if fault surfaces do not slip easily past one another, energy will be stored in elastically deformed rock, just as in a steel spring that is compressed. Currently, seismolo ...
... Earthquake forecasting is based largely on elastic rebound theory and plate tectonics. The elastic rebound theory suggests that if fault surfaces do not slip easily past one another, energy will be stored in elastically deformed rock, just as in a steel spring that is compressed. Currently, seismolo ...
Outer Core
... The magma is cooled and forms new ocean floor. The volcanic country of Iceland, which straddles the Mid-Atlantic Ridge, offers scientists a natural laboratory for studying on land the processes also occurring along the submerged parts of a spreading ridge. Iceland is splitting along the spreading ce ...
... The magma is cooled and forms new ocean floor. The volcanic country of Iceland, which straddles the Mid-Atlantic Ridge, offers scientists a natural laboratory for studying on land the processes also occurring along the submerged parts of a spreading ridge. Iceland is splitting along the spreading ce ...
1 Living with earthquakes and volcanoes
... moved around by currents inside the earth. Notice how in some places the plates are moving towards each other and in other places they are moving apart. Plate boundaries are the places where plates meet – this is where earthquakes and volcanoes often occur. ...
... moved around by currents inside the earth. Notice how in some places the plates are moving towards each other and in other places they are moving apart. Plate boundaries are the places where plates meet – this is where earthquakes and volcanoes often occur. ...
Deep structure of the northeastern Japan arc
... Seismic tomography studies in the northeastern Japan arc have revealed the existence of an inclined sheet-like seismic lowvelocity and high-attenuation zone in the mantle wedge at depths shallower than about 150 km. This sheet-like low-velocity, high-attenuation zone is oriented sub-parallel to the ...
... Seismic tomography studies in the northeastern Japan arc have revealed the existence of an inclined sheet-like seismic lowvelocity and high-attenuation zone in the mantle wedge at depths shallower than about 150 km. This sheet-like low-velocity, high-attenuation zone is oriented sub-parallel to the ...
Record - cloudfront.net
... definitions of morphotectonics, mostly taken from the glossary of Ufimtsev et a I • (1979) : L. Kober, 1928. The gross and major features of the earth. Genesis of tectonic structures in which an important part is played by geomorphic processes. E.S. Hills, 1961. A study of the external form and outl ...
... definitions of morphotectonics, mostly taken from the glossary of Ufimtsev et a I • (1979) : L. Kober, 1928. The gross and major features of the earth. Genesis of tectonic structures in which an important part is played by geomorphic processes. E.S. Hills, 1961. A study of the external form and outl ...
Changes in the tectonic regime above a subduction zone of andean
... Key words : xndea, faulting, stress patterns, Pliocene, GuaterNry ...
... Key words : xndea, faulting, stress patterns, Pliocene, GuaterNry ...
An Entirely New 3D-View of the Crustal and Mantle Structure of a
... The upper brittle continental crust tends to be a seismically poorly reflective layer, practically a blind zone (Figure 2). The top of the crystalline basement is rarely a significant reflection. Most of the times, it was tentatively interpreted at the basal termination of the reflective and stratif ...
... The upper brittle continental crust tends to be a seismically poorly reflective layer, practically a blind zone (Figure 2). The top of the crystalline basement is rarely a significant reflection. Most of the times, it was tentatively interpreted at the basal termination of the reflective and stratif ...
a 22 page PDF of this title
... height because they “float” on a dense, deformable layer beneath them. In a sense, they are supported at Earth’s surface in the same way a boat is supported by water. ...
... height because they “float” on a dense, deformable layer beneath them. In a sense, they are supported at Earth’s surface in the same way a boat is supported by water. ...
a non-technical guide to the geology of the burren region, co
... However, it is thought that an additional 2.5 km of sediments were deposited on top of the deltaic sediments, but were later eroded away (see below). Burial, gentle squashing and uplift After deposition, the rock sequence of the Burren region was gradually buried up to depths of ~ 2.5 km below the s ...
... However, it is thought that an additional 2.5 km of sediments were deposited on top of the deltaic sediments, but were later eroded away (see below). Burial, gentle squashing and uplift After deposition, the rock sequence of the Burren region was gradually buried up to depths of ~ 2.5 km below the s ...
Uplift of the western margin of the Andean plateau revealed from
... the valley floor in the middle reaches of the canyon, we know that the young apatite must have been exhumed from its closure depth to the near surface between 5.1 and 2.3 Ma. We explored probable erosion rates and depths to the closure temperature for this scenario using M. Brandon’s computer code A ...
... the valley floor in the middle reaches of the canyon, we know that the young apatite must have been exhumed from its closure depth to the near surface between 5.1 and 2.3 Ma. We explored probable erosion rates and depths to the closure temperature for this scenario using M. Brandon’s computer code A ...
World Tectonic Maps package as a pdf file
... delineate the Continental collision zones? Are these clear, narrow plate boundaries? The continental collisions show up as broad deformation zones. During the collision, many new breaks are formed and many older breaks are re-activated. ...
... delineate the Continental collision zones? Are these clear, narrow plate boundaries? The continental collisions show up as broad deformation zones. During the collision, many new breaks are formed and many older breaks are re-activated. ...
mantleplumes template.indd
... Azores, Jan Mayen, Yermak, and possibly Tristan da Cunha. All these “hot spots” have remained at or near the constructive boundary since their inception, possibly with the exception of Tristan da Cunha, which has a gap in the “hot spot track” on the west side of the S Atlantic, arguably marking a ju ...
... Azores, Jan Mayen, Yermak, and possibly Tristan da Cunha. All these “hot spots” have remained at or near the constructive boundary since their inception, possibly with the exception of Tristan da Cunha, which has a gap in the “hot spot track” on the west side of the S Atlantic, arguably marking a ju ...
Extensive drilling program planned for Glomar Challenger in
... the wire line method. In soft sediments at oceanic depths, about 100 meters of sediment can be cored per day. Recovery averages 50-75% of the total section cored, and consistent 100 17o recovery is rarely achieved. In hard limestone and cherts, core recovery is rarely more than 25%. Sand and gravel ...
... the wire line method. In soft sediments at oceanic depths, about 100 meters of sediment can be cored per day. Recovery averages 50-75% of the total section cored, and consistent 100 17o recovery is rarely achieved. In hard limestone and cherts, core recovery is rarely more than 25%. Sand and gravel ...
The cold and relatively dry nature of mantle forearcs in subduction
... (Fig. 3. and label number 46 on Fig. 4), conditions favouring early slab dehydration here have probably arisen only in the last 4 Myrs so the integrated effect should be less (See Supplementary Discussion 4). Costa Rica also shows very low Vp of 6.8–7.4 km s−1 in the shallowest part of the mantle we ...
... (Fig. 3. and label number 46 on Fig. 4), conditions favouring early slab dehydration here have probably arisen only in the last 4 Myrs so the integrated effect should be less (See Supplementary Discussion 4). Costa Rica also shows very low Vp of 6.8–7.4 km s−1 in the shallowest part of the mantle we ...
INTRODUCTION TO PETROLOGY
... H2O or CO2), solidus shifts to lower T melting can occur where T > solidus low seismic velocities indicate partial melting between 100-250 km (the LVZ) the LVZ marks the base of “plates” formed by rigid lithosphere ...
... H2O or CO2), solidus shifts to lower T melting can occur where T > solidus low seismic velocities indicate partial melting between 100-250 km (the LVZ) the LVZ marks the base of “plates” formed by rigid lithosphere ...
Post-glacial rebound
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Post-glacial rebound (sometimes called continental rebound) is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period, through a process known as isostatic depression. Post-glacial rebound and isostatic depression are different parts of a process known as either glacial isostasy, glacial isostatic adjustment, or glacioisostasy. Glacioisostasy is the solid Earth deformation associated with changes in ice mass distribution. The most obvious and direct affects of post-glacial rebound are readily apparent in northern Europe (especially Scotland, Estonia, Latvia, Fennoscandia, and northern Denmark), Siberia, Canada, the Great Lakes of Canada and the United States, the coastal region of the US state of Maine, parts of Patagonia, and Antarctica. However, through processes known as ocean siphoning and continental levering, the effects of post-glacial rebound on sea-level are felt globally far from the locations of current and former ice sheets.