Morphology and magnetic survey of the Rivera
... the western margin of the North American Plate has been recorded along the continental margin of North America from Alaska to Mexico (e.g. Atwater, 1989). The most recent collision appears off Manzanillo, Mexico (Figure 1), in the area located between the northern end of the PacificCocos segment of ...
... the western margin of the North American Plate has been recorded along the continental margin of North America from Alaska to Mexico (e.g. Atwater, 1989). The most recent collision appears off Manzanillo, Mexico (Figure 1), in the area located between the northern end of the PacificCocos segment of ...
Lasting mantle scars lead to perennial plate tectonics
... ML scars are well established in the geological record (for example, refs 1,4,6) but they have not received the same attention as, for example, the reactivation of faults within the Earth’s crust7 for localizing intraplate deformation. Experiments on rock properties find that deformation generates we ...
... ML scars are well established in the geological record (for example, refs 1,4,6) but they have not received the same attention as, for example, the reactivation of faults within the Earth’s crust7 for localizing intraplate deformation. Experiments on rock properties find that deformation generates we ...
Escape tectonics and the extrusion of Alaska: Past, present, and future
... the mobility of the present-day margin. Western British Columbia and southern Alaska constitute a diffuse plate boundary zone characterized by non-rigid deformation, mountain building, and block rotations (e.g., Stein and Freymueller, 2002). Here, we suggest that the “Bering Block” of Mackey et al., ...
... the mobility of the present-day margin. Western British Columbia and southern Alaska constitute a diffuse plate boundary zone characterized by non-rigid deformation, mountain building, and block rotations (e.g., Stein and Freymueller, 2002). Here, we suggest that the “Bering Block” of Mackey et al., ...
Lithospheric expression of cenozoic subduction, mesozoic rifting
... direct S (Yuan et al., 2006). In the Ps receiver function data, P-toS conversions from upper mantle structures, such as the LAB may interfere with crustal multiples, making it difficult to image the LAB with Ps receiver function data. Since S-to-P conversions arrive prior to direct S, and multiple refl ...
... direct S (Yuan et al., 2006). In the Ps receiver function data, P-toS conversions from upper mantle structures, such as the LAB may interfere with crustal multiples, making it difficult to image the LAB with Ps receiver function data. Since S-to-P conversions arrive prior to direct S, and multiple refl ...
A Plate Model for Jurassic to Recent Intraplate
... between intraplate volcanism and plate reorganisations, which suggests volcanism was controlled by fracturing and extension of the lithosphere. Middle Jurassic to Early Cretaceous intraplate volcanism included oceanic plateau formation at triple junctions (Shatsky Rise, western Mid Pacific Mountains ...
... between intraplate volcanism and plate reorganisations, which suggests volcanism was controlled by fracturing and extension of the lithosphere. Middle Jurassic to Early Cretaceous intraplate volcanism included oceanic plateau formation at triple junctions (Shatsky Rise, western Mid Pacific Mountains ...
Mantle detachment faults and the breakup of cold continental
... The results indicate that decoupling between the doming subcontinental mantle and the stretched continental crust is facilitated by strain localization into diffuse zones of high strain rates, forming mantle detachments with opposite dips. Lithospheric breakup in the absence of magmas starts with hi ...
... The results indicate that decoupling between the doming subcontinental mantle and the stretched continental crust is facilitated by strain localization into diffuse zones of high strain rates, forming mantle detachments with opposite dips. Lithospheric breakup in the absence of magmas starts with hi ...
Mantle convection in the Middle East: Reconciling Afar - HAL-Insu
... igneous province (Fig. 1b). Intraplate volcanism is also present in Syria–Jordan and Israel, far from the plate boundary, with large basaltic effusions and within the collisional zone, i.e. Eastern Anatolia, where the volcanic signature gets complicated by the mixed contributions of different geoche ...
... igneous province (Fig. 1b). Intraplate volcanism is also present in Syria–Jordan and Israel, far from the plate boundary, with large basaltic effusions and within the collisional zone, i.e. Eastern Anatolia, where the volcanic signature gets complicated by the mixed contributions of different geoche ...
Reconciling the geological history of western Turkey with plate
... collision and slab break-off. To this end, we compare the west Anatolian geological history with amounts of Africa– Europe convergence calculated from the Atlantic plate circuit, and the seismic tomography images of the west Anatolian mantle structure. Western Turkish geology reflects the convergence ...
... collision and slab break-off. To this end, we compare the west Anatolian geological history with amounts of Africa– Europe convergence calculated from the Atlantic plate circuit, and the seismic tomography images of the west Anatolian mantle structure. Western Turkish geology reflects the convergence ...
Geodynpub_files/Taiwan, 1997
... 2-D and 3-D physical modelling of lithospheric convergence in the Luzon-Taiwan-Ryukyu region is performed with properly scaled laboratory models. The lithospheric model consists of two parts, continental (the Asian Plate, AP) and oceanic (the Philippine Sea Plate, PSP). The oceanic lithosphere has o ...
... 2-D and 3-D physical modelling of lithospheric convergence in the Luzon-Taiwan-Ryukyu region is performed with properly scaled laboratory models. The lithospheric model consists of two parts, continental (the Asian Plate, AP) and oceanic (the Philippine Sea Plate, PSP). The oceanic lithosphere has o ...
Lecture 47
... The lithosphere is the part of the Earth through which heat is conducted rather than convected. Mantle lithosphere (the subcontinental lithospheric mantle: SCLM) tends to have fast seismic velocities, suggesting is cold compared with the convective mantle. Xenoliths derived from these regions) are o ...
... The lithosphere is the part of the Earth through which heat is conducted rather than convected. Mantle lithosphere (the subcontinental lithospheric mantle: SCLM) tends to have fast seismic velocities, suggesting is cold compared with the convective mantle. Xenoliths derived from these regions) are o ...
1 Imaging the transition from flat to normal subduction: Variations in
... result of vertical smearing of low velocity anomalies in the crust down into the mantle, resulting ...
... result of vertical smearing of low velocity anomalies in the crust down into the mantle, resulting ...
Author`s personal copy - Laboratoire de Planétologie et
... assimilation in shallow magma chambers emplaced along transtensional to extensional zones. The close association of bimodal magmatism with extensional tectonic features in the western MLBA is a strong support to the model of Patagonian collapse event proposed to have taken place between 5 and 3 Ma a ...
... assimilation in shallow magma chambers emplaced along transtensional to extensional zones. The close association of bimodal magmatism with extensional tectonic features in the western MLBA is a strong support to the model of Patagonian collapse event proposed to have taken place between 5 and 3 Ma a ...
Early cretaceous subduction-related adakite
... (2005). Sample T203A was analyzed for major elements by X-ray fluorescence using a Rigaku RIX-2000 spectrometer and for trace elements by ICP-MS using an AgilentÒ 7500s, both housed at the Department of Geosciences, National Taiwan University, Taiwan; further details can be found in Chung et al. (200 ...
... (2005). Sample T203A was analyzed for major elements by X-ray fluorescence using a Rigaku RIX-2000 spectrometer and for trace elements by ICP-MS using an AgilentÒ 7500s, both housed at the Department of Geosciences, National Taiwan University, Taiwan; further details can be found in Chung et al. (200 ...
tectonics - GeoKniga
... the asthenosphere, a layer that behaves plastically (meaning that, though solid, it can flow). The asthenosphere lies entirely within the mantle. A background on whole Earth structure sets the stage for introducing plate tectonics theory (or simply, “plate tectonics”). According to this theory, the ...
... the asthenosphere, a layer that behaves plastically (meaning that, though solid, it can flow). The asthenosphere lies entirely within the mantle. A background on whole Earth structure sets the stage for introducing plate tectonics theory (or simply, “plate tectonics”). According to this theory, the ...
Seismic structure of the lithosphere and upper mantle
... another low-velocity layer (L). All these phases have their amplitudes above the 2 sigma error limit. Although the positive conversions from the Moho and a negative one from the LAB are prominent in this figure, the multiples from either of these are not obvious. This could be because of to their an ...
... another low-velocity layer (L). All these phases have their amplitudes above the 2 sigma error limit. Although the positive conversions from the Moho and a negative one from the LAB are prominent in this figure, the multiples from either of these are not obvious. This could be because of to their an ...
FREE Sample Here
... 11) During the geologic past, the magnetic field poles have generally been very close to Earth's geographical poles. Answer: TRUE Diff: 1 12) Seafloor spreading rates can be estimated if the geologic ages of the magnetic field reversals are independently known. Answer: TRUE Diff: 2 13) The volcanoes ...
... 11) During the geologic past, the magnetic field poles have generally been very close to Earth's geographical poles. Answer: TRUE Diff: 1 12) Seafloor spreading rates can be estimated if the geologic ages of the magnetic field reversals are independently known. Answer: TRUE Diff: 2 13) The volcanoes ...
Crustal and uppermantle structure in the Eastern Mediterranean
... subduction system to the west and the convergence of the plates to the east produces the westward motion of the Anatolian microplate, which is bounded by strikeslip faults, the dextral North Anatolian Fault (NAF) to the north and the leftlateral East Anatolian Fault Zone ...
... subduction system to the west and the convergence of the plates to the east produces the westward motion of the Anatolian microplate, which is bounded by strikeslip faults, the dextral North Anatolian Fault (NAF) to the north and the leftlateral East Anatolian Fault Zone ...
3.20 Trace Element and Isotopic Fluxes
... Figure 4 LOI and SiO2/Al2O3 for HP paleoaccretionary metasedimentary rocks and their likely seafloor sedimentary equivalents (figure from Sadofsky and Bebout, 2003). Note that LOI correlates with SiO2/Al2O3 for the Catalina Schist (data from Bebout et al., 1999), Franciscan Complex Coast Ranges, Calif ...
... Figure 4 LOI and SiO2/Al2O3 for HP paleoaccretionary metasedimentary rocks and their likely seafloor sedimentary equivalents (figure from Sadofsky and Bebout, 2003). Note that LOI correlates with SiO2/Al2O3 for the Catalina Schist (data from Bebout et al., 1999), Franciscan Complex Coast Ranges, Calif ...
Immobile Element Fingerprinting of Ophiolites
... are also those long known to be the least mobile during rock weathering: they are all characterised by intermediate charge/radius (Z/r) ratios, such that they do not readily form soluble hydrated cations (low Z/r), complex anions (high Z/r) or chloride complexes in fluids. A number of authors have, ...
... are also those long known to be the least mobile during rock weathering: they are all characterised by intermediate charge/radius (Z/r) ratios, such that they do not readily form soluble hydrated cations (low Z/r), complex anions (high Z/r) or chloride complexes in fluids. A number of authors have, ...
ppt
... areas where the continental crust has been thickened by orogeny, either continental arc subduction or collision of sialic masses. Many granites, however, may post-date the thickening event by tens of millions of years. 2) Because the crust is solid in its normal state, some thermal disturbance is re ...
... areas where the continental crust has been thickened by orogeny, either continental arc subduction or collision of sialic masses. Many granites, however, may post-date the thickening event by tens of millions of years. 2) Because the crust is solid in its normal state, some thermal disturbance is re ...
Earth`sInterior WS-W.. - J-DESC
... gabbro/peridotite transitions in the Oman ophiolite. Gabbro/peridotite boundaries; diversity and classification Layered gabbros grade downward to peridotites in various ways in the Oman ophiolite. 1. Gabbro-in-dunite boundaries. Layered gabbros change to peridotites (mainly dunite) via gabbro layers ...
... gabbro/peridotite transitions in the Oman ophiolite. Gabbro/peridotite boundaries; diversity and classification Layered gabbros grade downward to peridotites in various ways in the Oman ophiolite. 1. Gabbro-in-dunite boundaries. Layered gabbros change to peridotites (mainly dunite) via gabbro layers ...
Lecture 12: Surface Processes I
... meaning their long term Lu/Hf and Sm/Nd ratios have been higher than chondritic. But nearly all MORB samples have subchondritic measured Lu/Hf and Sm/Nd ratios. • It follows that Lu/Hf and Sm/Nd were fractionated recently (by the melting process itself), which turns out to requires garnet in the sou ...
... meaning their long term Lu/Hf and Sm/Nd ratios have been higher than chondritic. But nearly all MORB samples have subchondritic measured Lu/Hf and Sm/Nd ratios. • It follows that Lu/Hf and Sm/Nd were fractionated recently (by the melting process itself), which turns out to requires garnet in the sou ...
Large igneous provinces linked to supercontinent assembly
... 2014), coexist with rhyolite and other felsic rocks, suggesting that they are related instead to a rift system. These rock types were emplaced over a long interval, from ∼290 to 275 Ma. Fifth, so-called “primary magma” in the Emeishan LIP (Zhang et al., 2006) was actually sourced from the lithospher ...
... 2014), coexist with rhyolite and other felsic rocks, suggesting that they are related instead to a rift system. These rock types were emplaced over a long interval, from ∼290 to 275 Ma. Fifth, so-called “primary magma” in the Emeishan LIP (Zhang et al., 2006) was actually sourced from the lithospher ...
Upper plate proxies for flat-slab subduction processes in southern
... eastern Alaska. Collectively, these geologic data indicate that flat-slab subduction was shaping southern Alaska by late Eocene–early Oligocene time, much earlier than previous models infer. Upper plate processes related to subduction of a flat slab in Alaska are similar to those documented in other m ...
... eastern Alaska. Collectively, these geologic data indicate that flat-slab subduction was shaping southern Alaska by late Eocene–early Oligocene time, much earlier than previous models infer. Upper plate processes related to subduction of a flat slab in Alaska are similar to those documented in other m ...
The Oceanic Lithosphere
... GEOPHYSICS AND GEOCHEMISTRY – Vol. II - The Oceanic Lithosphere - Javier Escartín ...
... GEOPHYSICS AND GEOCHEMISTRY – Vol. II - The Oceanic Lithosphere - Javier Escartín ...
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.