Karson, J.A., and Lawrence, R.M., 1997.
... struction that builds the oceanic crust, and (2) faulting that thins and disrupts the crust. In general, the relationship between these two processes is governed by the "magma budget," defined as the volume of magma per unit of plate separation (Karson and Winters, 1992), Where the magma budget is r ...
... struction that builds the oceanic crust, and (2) faulting that thins and disrupts the crust. In general, the relationship between these two processes is governed by the "magma budget," defined as the volume of magma per unit of plate separation (Karson and Winters, 1992), Where the magma budget is r ...
Ultrahigh-pressure metamorphism: tracing continental crust into the
... the rock passed at some stage through UHP conditions, and this may imply entire reconsideration of the geological or structural record for the area. Given these far-reaching implications, a prerequisite is that the mineralogical evidence is unambiguously characterized ^ and demonstrably in situ. Tec ...
... the rock passed at some stage through UHP conditions, and this may imply entire reconsideration of the geological or structural record for the area. Given these far-reaching implications, a prerequisite is that the mineralogical evidence is unambiguously characterized ^ and demonstrably in situ. Tec ...
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... the types of strucEural uration, the nature of the stratigraphic hydrocarbons in space and time. features, and the location of fluid favorable to hydrocarbon occurrence include the attributes Critical of thermal flux apPropresence of organic-rich source beds, a history migration paths to a1low conpr ...
... the types of strucEural uration, the nature of the stratigraphic hydrocarbons in space and time. features, and the location of fluid favorable to hydrocarbon occurrence include the attributes Critical of thermal flux apPropresence of organic-rich source beds, a history migration paths to a1low conpr ...
Crustal structure beneath the Strait of Juan de Fuca and southern
... thick band of high reflectivity which dips eastward from around 20 to 33 km depth [Yorath et al., 1985] (Figure 2). There have been a variety of subduction-related interpretations for the origin of this reflective layer, generally referred to as the ‘‘E’’ reflectivity band. Calvert and Clowes [1990] ...
... thick band of high reflectivity which dips eastward from around 20 to 33 km depth [Yorath et al., 1985] (Figure 2). There have been a variety of subduction-related interpretations for the origin of this reflective layer, generally referred to as the ‘‘E’’ reflectivity band. Calvert and Clowes [1990] ...
2D finite element modeling
... margin, central-south Alaska. The accretionary prism is assumed to be elastic continuum. The subduction of the Pacific plate beneath the North American plate and the underplating of the oceanic crust is subjected as the boundary condition. The first episode of the Late Cretaceous accretion is modeled ...
... margin, central-south Alaska. The accretionary prism is assumed to be elastic continuum. The subduction of the Pacific plate beneath the North American plate and the underplating of the oceanic crust is subjected as the boundary condition. The first episode of the Late Cretaceous accretion is modeled ...
Extrapolating Oceanic Age Distributions
... observable data exist that directly constrain the motions beyond the youngest magnetic reversal–dated oceanic lithosphere along such a boundary. This mode has, for example, been employed to extrapolate the age distribution resulting from spreading along the Izanagi-Pacific ridge system for as much a ...
... observable data exist that directly constrain the motions beyond the youngest magnetic reversal–dated oceanic lithosphere along such a boundary. This mode has, for example, been employed to extrapolate the age distribution resulting from spreading along the Izanagi-Pacific ridge system for as much a ...
Dipping reflector sequences in the vicinity of the continent
... by the occurrence of intrabasement reflectors but is strongly contradicted over continental crust by the observation of inter-formational sedimentarytype structures, and the shallow basinal form to the dipping sequences, occasionally observed between inner and outer 'highs'. ...
... by the occurrence of intrabasement reflectors but is strongly contradicted over continental crust by the observation of inter-formational sedimentarytype structures, and the shallow basinal form to the dipping sequences, occasionally observed between inner and outer 'highs'. ...
Chiarenzelli, J., Regan, S., Peck, W., Selleck, B., Cousens, B., Baird, G. and Shrady, C. (2010)
... to further education and science. This file may not be posted to any Web site, but authors may post the abstracts only of their articles on their own or their organization's Web site providing the posting includes a reference to the article's full citation. GSA provides this and other forums for the ...
... to further education and science. This file may not be posted to any Web site, but authors may post the abstracts only of their articles on their own or their organization's Web site providing the posting includes a reference to the article's full citation. GSA provides this and other forums for the ...
Paleogene–early Miocene igneous rocks and geodynamics of the
... Miocene igneous rocks of all these areas were formed along a single, subduction-related magmatic arc. The study also highlights orthopyroxene-rich websterite mantle xenoliths from west Hungary and east Serbia that were formed in the vicinity of a subducted slab. We discuss the location and polarity ...
... Miocene igneous rocks of all these areas were formed along a single, subduction-related magmatic arc. The study also highlights orthopyroxene-rich websterite mantle xenoliths from west Hungary and east Serbia that were formed in the vicinity of a subducted slab. We discuss the location and polarity ...
The SNC meteorites: basaltic igneous processes on Mars
... orthopyroxenite. We show that the shergottites can be also be subclassified geochemically on the basis of their degree of light rare earth element (LREE) depletion. We use new trace element data to model cumulate processes in the nakhlite magma chamber. Variable patterns of depletion in incompatible ...
... orthopyroxenite. We show that the shergottites can be also be subclassified geochemically on the basis of their degree of light rare earth element (LREE) depletion. We use new trace element data to model cumulate processes in the nakhlite magma chamber. Variable patterns of depletion in incompatible ...
The Central Basin Spreading Center in the Philippine Sea: Structure
... considered to have ceased spreading in the middle Oligocene. Satellite gravity data suggest that the spreading system is located near oceanic plateaus and seamount chains in its western part and is connected to the remnant arc at its eastern end. The CBSC provides an ideal setting for the investigat ...
... considered to have ceased spreading in the middle Oligocene. Satellite gravity data suggest that the spreading system is located near oceanic plateaus and seamount chains in its western part and is connected to the remnant arc at its eastern end. The CBSC provides an ideal setting for the investigat ...
The Central Basin Spreading Center in the Philippine Sea
... considered to have ceased spreading in the middle Oligocene. Satellite gravity data suggest that the spreading system is located near oceanic plateaus and seamount chains in its western part and is connected to the remnant arc at its eastern end. The CBSC provides an ideal setting for the investigat ...
... considered to have ceased spreading in the middle Oligocene. Satellite gravity data suggest that the spreading system is located near oceanic plateaus and seamount chains in its western part and is connected to the remnant arc at its eastern end. The CBSC provides an ideal setting for the investigat ...
Unusual nickel and copper to noble
... formation of the Tverrfjell rocks, or that the Eiterdalen rocks are enriched in olivine and chro mite relative to the Tverrfjell samples. The Eiter dalen rocks consist of plagioclase, bomblende and sulphides and do not appear to be enriched in olivine and chromite. Therefore the difference in Pd/I ...
... formation of the Tverrfjell rocks, or that the Eiterdalen rocks are enriched in olivine and chro mite relative to the Tverrfjell samples. The Eiter dalen rocks consist of plagioclase, bomblende and sulphides and do not appear to be enriched in olivine and chromite. Therefore the difference in Pd/I ...
Eclogite-facies shear zones-deep crustal reflectors?
... determined, V, for the granulite-facies protoliths average about 7.5 km s - ‘. High calculated reflection coefficients for these shear zones, 0.04-0.14, indicate that they are excellent candidates for deep crustal reflectors in portions of crust that experienced high-pressure conditions but escaped ...
... determined, V, for the granulite-facies protoliths average about 7.5 km s - ‘. High calculated reflection coefficients for these shear zones, 0.04-0.14, indicate that they are excellent candidates for deep crustal reflectors in portions of crust that experienced high-pressure conditions but escaped ...
Geology of Ethiopia
... the closure of the Mozambique ocean between West and East Gondwana with the development of the Ethiopian basement ranging in age from 880 to 550 Ma. This folded and tilted Proterozoic basement underwent intense erosion, which lasted one hundred million years, and destroyed any relief of the Precambr ...
... the closure of the Mozambique ocean between West and East Gondwana with the development of the Ethiopian basement ranging in age from 880 to 550 Ma. This folded and tilted Proterozoic basement underwent intense erosion, which lasted one hundred million years, and destroyed any relief of the Precambr ...
A Geochemical Study of Crustal Plutonic Rocks from the Southern
... The locations of the dredges are significant as the area contains volcanic rocks (forearc basalts and boninites) that have been pivotal in explaining processes that occur when one lithospheric plate initially begins to subduct beneath another. The plutonic rocks have been classified based on petrolo ...
... The locations of the dredges are significant as the area contains volcanic rocks (forearc basalts and boninites) that have been pivotal in explaining processes that occur when one lithospheric plate initially begins to subduct beneath another. The plutonic rocks have been classified based on petrolo ...
Article - The Oceanography Society
... from the buoyancy of rising mantle or due to heating of the lithosphere from below. However, as soon as a seamount has reached a critical size, subsidence becomes the dominant vertical force, caused by the bending of the oceanic crust into the mantle as it yields to the seamount load (Watts, 2001). ...
... from the buoyancy of rising mantle or due to heating of the lithosphere from below. However, as soon as a seamount has reached a critical size, subsidence becomes the dominant vertical force, caused by the bending of the oceanic crust into the mantle as it yields to the seamount load (Watts, 2001). ...
Yin and yang of continental crust creation and destruction by plate
... Mature continental crust is compositionally layered and can be subdivided into upper continental crust (∼20 km thick) of approximately granodioritic composition and lower, mafic crust (∼20 km thick), separated by a Conrad discontinuity that is well to weakly formed (Christensen and Mooney 1995; Rudn ...
... Mature continental crust is compositionally layered and can be subdivided into upper continental crust (∼20 km thick) of approximately granodioritic composition and lower, mafic crust (∼20 km thick), separated by a Conrad discontinuity that is well to weakly formed (Christensen and Mooney 1995; Rudn ...
Upper mantle anisotropy of southeast Arabia passive margin [Gulf of
... the observed regional anisotropy trend observed mostly in western parts of the Arabian plate, it may be expected that the measured anisotropy orientations reflect either partially or entirely some association with the Gulf of Aden opening process. The observed anisotropy orientations represent a con ...
... the observed regional anisotropy trend observed mostly in western parts of the Arabian plate, it may be expected that the measured anisotropy orientations reflect either partially or entirely some association with the Gulf of Aden opening process. The observed anisotropy orientations represent a con ...
The continent marginal crust characteristic of nothern South China
... oceanic crust should be behind ca 380 km because the thin crustal thickness (frame B; ca 6-8 km), the relatively high values both on bouguer anomaly (frame B’) and magnetic anomaly (frame B”). Another place we should notice is the position surrounded by frame A. A relatively high magnetic anomaly ta ...
... oceanic crust should be behind ca 380 km because the thin crustal thickness (frame B; ca 6-8 km), the relatively high values both on bouguer anomaly (frame B’) and magnetic anomaly (frame B”). Another place we should notice is the position surrounded by frame A. A relatively high magnetic anomaly ta ...
Mantle plume
A mantle plume is a mechanism proposed in 1971 to explain volcanic regions of the earth that were not thought to be explicable by the then-new theory of plate tectonics. Some such volcanic regions lie far from tectonic plate boundaries, for example, Hawaii. Others represent unusually large-volume volcanism, whether on plate boundaries, e.g. Iceland, or basalt floods such as the Deccan or Siberian traps.A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. The currently active volcanic centers are known as ""hot spots"". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.The hypothesis of mantle plumes from depth is not universally accepted as explaining all such volcanism. It has required progressive hypothesis-elaboration leading to variant propositions such as mini-plumes and pulsing plumes. Another hypothesis for unusual volcanic regions is the ""Plate model"". This proposes shallower, passive leakage of magma from the mantle onto the Earth's surface where extension of the lithosphere permits it, attributing most volcanism to plate tectonic processes, with volcanoes far from plate boundaries resulting from intraplate extension.