North Atlantic Igneous Province: A Review of
... covered by flood basalts, both onshore and offshore, may represent ~1.3x10 km with a ...
... covered by flood basalts, both onshore and offshore, may represent ~1.3x10 km with a ...
here - W. Steven Holbrook
... are generated in arcs and which are acquired during later events. Our results provide an opportunity to compare three large-scale properties—thickness, bulk composition, and internal structure—between Aleutian island-arc crust and mature continental crust. Our results suggest that the thickness of c ...
... are generated in arcs and which are acquired during later events. Our results provide an opportunity to compare three large-scale properties—thickness, bulk composition, and internal structure—between Aleutian island-arc crust and mature continental crust. Our results suggest that the thickness of c ...
Uncertainties and implications of the Late Cretaceous and Tertiary
... to plate motions is western North America, where important variations in tectonic style, rates of deformation, and magmatic patterns have occurred both along and ...
... to plate motions is western North America, where important variations in tectonic style, rates of deformation, and magmatic patterns have occurred both along and ...
Physics of the Earth and Planetary Interiors Supercontinent
... form in stagnation regions of the CMB that are commonly below the central regions of major tectonic plates and are controlled by the distribution of subducted slabs, consistent with the statistical analysis of hot spot distribution (Weinstein and Olson, 1989) and seismic tomography imaging (e.g., No ...
... form in stagnation regions of the CMB that are commonly below the central regions of major tectonic plates and are controlled by the distribution of subducted slabs, consistent with the statistical analysis of hot spot distribution (Weinstein and Olson, 1989) and seismic tomography imaging (e.g., No ...
Mobility and immobility of mid-ocean ridges and their
... 1and Figure 2). All ridges appear to be migrating: the East Pacific Rise (EPR) appears to have rotated clockwise for about 50° since 83Ma (Figure 2i). The South Mid Atlantic ...
... 1and Figure 2). All ridges appear to be migrating: the East Pacific Rise (EPR) appears to have rotated clockwise for about 50° since 83Ma (Figure 2i). The South Mid Atlantic ...
Generation of plate tectonics from mantle convection
... Southam and Westall, 2007) (Chapter 10.14). The discovery of many terrestrial planets in other solar systems over the last 15 years (e.g., Charbonneau et al., 2009) has, therefore, emphasized that the existence of plate tectonics is possibly a necessary condition for biological habitability (Foley e ...
... Southam and Westall, 2007) (Chapter 10.14). The discovery of many terrestrial planets in other solar systems over the last 15 years (e.g., Charbonneau et al., 2009) has, therefore, emphasized that the existence of plate tectonics is possibly a necessary condition for biological habitability (Foley e ...
Lithium Isotope Variations in Ocean Island
... The Author 2012. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@ oup.com ...
... The Author 2012. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@ oup.com ...
Iceland is cool: An origin for the Iceland volcanic province in the
... Observations from the Iceland region that appear paradoxical in the plume model are as follows. Since the opening of the north Atlantic at ~ 54 Ma, the locus of melt extraction has been at the mid-Atlantic ridge (MAR) where it crosses the Caledonian suture. In the context of a plume, this is a coinc ...
... Observations from the Iceland region that appear paradoxical in the plume model are as follows. Since the opening of the north Atlantic at ~ 54 Ma, the locus of melt extraction has been at the mid-Atlantic ridge (MAR) where it crosses the Caledonian suture. In the context of a plume, this is a coinc ...
Depositional Environment of Cherts of the Sikhote
... within the sedimentary formations of the Mesozoic accretionary complexes of the Sikhote-Alin region. The bedded chert units are 20–100 m thick and occur in tectonic slices up to 40 km in strike length. These tectonic slices alternate with slices of terrigenous rocks, and to a lesser extent with slic ...
... within the sedimentary formations of the Mesozoic accretionary complexes of the Sikhote-Alin region. The bedded chert units are 20–100 m thick and occur in tectonic slices up to 40 km in strike length. These tectonic slices alternate with slices of terrigenous rocks, and to a lesser extent with slic ...
The thermochemical structure and evolution of Earth`s mantle
... by recycling of residuum, although the resulting high-3 He/4 He material tends to aggregate near the top, where mid-ocean-ridge melting should sample it. If primitive material exists as a dense basal layer, it must be much denser than subducted crust in order to retain its primitive (e.g. high-3 He) ...
... by recycling of residuum, although the resulting high-3 He/4 He material tends to aggregate near the top, where mid-ocean-ridge melting should sample it. If primitive material exists as a dense basal layer, it must be much denser than subducted crust in order to retain its primitive (e.g. high-3 He) ...
Evidence of low flexural rigidity and low viscosity lower continental... during continental break-up in the South China Sea
... Fig. 1. Bathymetric map of the South China Sea showing the principle geologic and physical features that define the basin, together with the locations of multichannel seismic data considered in this study. COT, continent–ocean transition. Water depths in meters. ...
... Fig. 1. Bathymetric map of the South China Sea showing the principle geologic and physical features that define the basin, together with the locations of multichannel seismic data considered in this study. COT, continent–ocean transition. Water depths in meters. ...
Mountain Building Processes in Four-Dimensions (4D-MB)
... mission. It will test the hypothesis that re-organizations of Earth’s mantle during the collision of tectonic plates have both immediate and long-lasting effects on earthquake distribution, crustal motion and landscape evolution in mountain belts. 4D-MB challenges conventional wisdom by recognising ...
... mission. It will test the hypothesis that re-organizations of Earth’s mantle during the collision of tectonic plates have both immediate and long-lasting effects on earthquake distribution, crustal motion and landscape evolution in mountain belts. 4D-MB challenges conventional wisdom by recognising ...
Plate boundary deformation between the Pacific and North America
... the North American (NAM) and Pacific (PAC) plates. The velocity field derived from the inversion of the earthquake strain rates indicates that seismic activity takes up 50 š 30% .1¦ / of the PAC–NAM relative motion (NUVEL-1A; DeMets et al., 1994. Effect of recent revisions to the geomagnetic reversa ...
... the North American (NAM) and Pacific (PAC) plates. The velocity field derived from the inversion of the earthquake strain rates indicates that seismic activity takes up 50 š 30% .1¦ / of the PAC–NAM relative motion (NUVEL-1A; DeMets et al., 1994. Effect of recent revisions to the geomagnetic reversa ...
(1998) Quaternary uplift of the New Georgia Island Group
... The New Georgia Island Group of the Solomon Islands is one of four places where an active or recently active spreading ridge has subducted beneath an island arc. We have used coral reef terraces, paleobathymetry of Neogene sedimentary rocks, and existing marine geophysical data to constrain patterns ...
... The New Georgia Island Group of the Solomon Islands is one of four places where an active or recently active spreading ridge has subducted beneath an island arc. We have used coral reef terraces, paleobathymetry of Neogene sedimentary rocks, and existing marine geophysical data to constrain patterns ...
Petrology and tectonics of Phanerozoic continent formation: From
... be linked in space and time. Subduction of the Farallon plate beneath North America during the Triassic to early Cretaceous was characterized by trench retreat and slab rollback because old and cold oceanic lithosphere was being subducted. This generated an extensional subduction zone, which created ...
... be linked in space and time. Subduction of the Farallon plate beneath North America during the Triassic to early Cretaceous was characterized by trench retreat and slab rollback because old and cold oceanic lithosphere was being subducted. This generated an extensional subduction zone, which created ...
Dipping reflector sequences in the vicinity of the continent
... on the Law of the Sea (1980) includes a number of proposed criteria for the delineation of the continental shelf of a coastal state, where its margin extends beyond 200 nautical miles from the continental baseline. One of these criteria, (para. 4(a), (i)), the so-called 'Irish formula' requires the ...
... on the Law of the Sea (1980) includes a number of proposed criteria for the delineation of the continental shelf of a coastal state, where its margin extends beyond 200 nautical miles from the continental baseline. One of these criteria, (para. 4(a), (i)), the so-called 'Irish formula' requires the ...
2.1.1 Introduction
... fault imparts only shearing motions in their directions; they are consequently known as nodal planes. Simplistically, then, a focal mechanism solution could be obtained by recording an earthquake at a number of seismographs distributed around its epicenter, determining the nature of the first motion ...
... fault imparts only shearing motions in their directions; they are consequently known as nodal planes. Simplistically, then, a focal mechanism solution could be obtained by recording an earthquake at a number of seismographs distributed around its epicenter, determining the nature of the first motion ...
Geophysical Journal International
... as reconstructed in Vergés et al. (2011). The Sanandaj Sirjan zone (SSZ) is an Iranian continental block involving Palaeozoic to Cretaceous sedimentary and metamorphic rocks. This zone is thrusted to the SW, on top of the MZF. The Tertiary Urumieh Dokhtar Magmatic Arc (UDMA) formed on the Iranian c ...
... as reconstructed in Vergés et al. (2011). The Sanandaj Sirjan zone (SSZ) is an Iranian continental block involving Palaeozoic to Cretaceous sedimentary and metamorphic rocks. This zone is thrusted to the SW, on top of the MZF. The Tertiary Urumieh Dokhtar Magmatic Arc (UDMA) formed on the Iranian c ...
Lithosphere, Asthenosphere, and Perisphere
... awayfrom spreading inducedupwelling. EM is therefore probably shallow. It is not known if volatiles and large-ion lithophiles can recycle much deeper than ---200km, or into the lower mantle, as is implied by someplume theories. The base of the (strong) lithosphere and plate may correspond to a phase ...
... awayfrom spreading inducedupwelling. EM is therefore probably shallow. It is not known if volatiles and large-ion lithophiles can recycle much deeper than ---200km, or into the lower mantle, as is implied by someplume theories. The base of the (strong) lithosphere and plate may correspond to a phase ...
Elsevier Publishing Company, Amsterdam
... shelf-break. The continental rise, which aprons the base of the slope, has a steeper upper segment in some areas. Relief associated with leveed channels interrupts the seaward slope of the rise. The lower rise is characteristically smooth and its seaward slope is O' 01' (1:350) or less. Intersection ...
... shelf-break. The continental rise, which aprons the base of the slope, has a steeper upper segment in some areas. Relief associated with leveed channels interrupts the seaward slope of the rise. The lower rise is characteristically smooth and its seaward slope is O' 01' (1:350) or less. Intersection ...
Origin of ocean island basalts: A new perspective from petrology
... and White [1998] on many OIB also define the mantle or ‘‘terrestrial’’ array [Vervoort et al., 1999] with global coverage both geographically and in Nd-Hf isotope ratio space. 2.3. Recycled Oceanic Crusts After Subduction Zone Dehydration Unsuitable as Sources for OIB [10] The ocean crust is altered ...
... and White [1998] on many OIB also define the mantle or ‘‘terrestrial’’ array [Vervoort et al., 1999] with global coverage both geographically and in Nd-Hf isotope ratio space. 2.3. Recycled Oceanic Crusts After Subduction Zone Dehydration Unsuitable as Sources for OIB [10] The ocean crust is altered ...
Petrological interpretation of deep crustal intrusive bodies beneath
... provinces reveal the presence of ultramafic bodies with P-wave velocities of Vp ~ 7.4–8.0 km/s lying at or above the Moho, e.g., Hawaii, the Marquesas, and La Reunion. However, at other hotspot provinces such as the Galapagos, Nazca Ridge, and Louisville the lower crust is intruded by large volumes o ...
... provinces reveal the presence of ultramafic bodies with P-wave velocities of Vp ~ 7.4–8.0 km/s lying at or above the Moho, e.g., Hawaii, the Marquesas, and La Reunion. However, at other hotspot provinces such as the Galapagos, Nazca Ridge, and Louisville the lower crust is intruded by large volumes o ...
An ultraslow-spreading class of ocean ridge
... Magmatic segments form sub-perpendicularly to the least principal compressive stress, at an angle intermediate to the ridge trend and orthogonal to the spreading direction, for example21,22. Morphologically, they consist of linear axial highs or troughs with saddle points at the segment centres and ...
... Magmatic segments form sub-perpendicularly to the least principal compressive stress, at an angle intermediate to the ridge trend and orthogonal to the spreading direction, for example21,22. Morphologically, they consist of linear axial highs or troughs with saddle points at the segment centres and ...
An ultraslow-spreading class of ocean ridge
... Magmatic segments form sub-perpendicularly to the least principal compressive stress, at an angle intermediate to the ridge trend and orthogonal to the spreading direction, for example21,22. Morphologically, they consist of linear axial highs or troughs with saddle points at the segment centres and ...
... Magmatic segments form sub-perpendicularly to the least principal compressive stress, at an angle intermediate to the ridge trend and orthogonal to the spreading direction, for example21,22. Morphologically, they consist of linear axial highs or troughs with saddle points at the segment centres and ...
Chapter 14. Magmas: Windows into the Mantle
... model involves transport of cold slabs, including the crust, to the core-mantle boundary (CMB) where they heat up and generate ~ 3000 km deep narrow plumes that come up under oceanic islands . Enrichment of the lower part of the lithosphere by upward migrating metasomatic melts and fluids, and ineff ...
... model involves transport of cold slabs, including the crust, to the core-mantle boundary (CMB) where they heat up and generate ~ 3000 km deep narrow plumes that come up under oceanic islands . Enrichment of the lower part of the lithosphere by upward migrating metasomatic melts and fluids, and ineff ...
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.