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... [1] We present major, trace element, and Pb‐Sr‐Nd‐Hf isotope data for Quaternary basalt and basaltic andesite lavas from cross‐chain volcanoes in the northern Izu (N‐Izu) arc. Lavas from Izu‐Oshima, Toshima, Udonejima, and Niijima islands show consistent chemical changes with depth to the Wadati‐Ben ...
... [1] We present major, trace element, and Pb‐Sr‐Nd‐Hf isotope data for Quaternary basalt and basaltic andesite lavas from cross‐chain volcanoes in the northern Izu (N‐Izu) arc. Lavas from Izu‐Oshima, Toshima, Udonejima, and Niijima islands show consistent chemical changes with depth to the Wadati‐Ben ...
A Dynamic Model of Rifting Between Galicia Bank and Flemish Cap
... Regardless of the complexities of late rift-stage and early spreading phase melt production, there is broad consensus that for most of the rift history the margins were amagmatic, or at least involved very little melt production. Volcanism that occurred prior to the onset of seafloor spreading appea ...
... Regardless of the complexities of late rift-stage and early spreading phase melt production, there is broad consensus that for most of the rift history the margins were amagmatic, or at least involved very little melt production. Volcanism that occurred prior to the onset of seafloor spreading appea ...
2D finite element modeling
... accretionary prism at di#erent stages during the Late Cretaceous accretion of Mesozoic melange belts (McHugh Complex and Iceworm melamges) in the Chugach convergent margin, central-south Alaska. The accretionary prism is assumed to be elastic continuum. The subduction of the Pacific plate beneath the ...
... accretionary prism at di#erent stages during the Late Cretaceous accretion of Mesozoic melange belts (McHugh Complex and Iceworm melamges) in the Chugach convergent margin, central-south Alaska. The accretionary prism is assumed to be elastic continuum. The subduction of the Pacific plate beneath the ...
Behavior of subducting sediments beneath an arc under a high
... and basalts are considered to be produced by the subducted sediment melting (Shimoda et al., 1998), these magmas are characterized by high Nb and Zr concentrations (up to 12 ppm and 120 ppm, respectively; Shimoda et al., 1998). This geochemical feature suggests that there is no residual phase which ...
... and basalts are considered to be produced by the subducted sediment melting (Shimoda et al., 1998), these magmas are characterized by high Nb and Zr concentrations (up to 12 ppm and 120 ppm, respectively; Shimoda et al., 1998). This geochemical feature suggests that there is no residual phase which ...
Bebout Metamorphic chemical geodynamics of subduction zones
... 2003; McKenzie et al., 2004; Fig. 1). In the best case, these metamorphic suites, which contain sedimentary and igneous lithologies with appropriate seafloor protoliths, directly reflect geochemical evolution at/near the slab– mantle interface and can help us further characterize slab processes only ...
... 2003; McKenzie et al., 2004; Fig. 1). In the best case, these metamorphic suites, which contain sedimentary and igneous lithologies with appropriate seafloor protoliths, directly reflect geochemical evolution at/near the slab– mantle interface and can help us further characterize slab processes only ...
Metamorphic chemical geodynamics of subduction zones
... 2003; McKenzie et al., 2004; Fig. 1). In the best case, these metamorphic suites, which contain sedimentary and igneous lithologies with appropriate seafloor protoliths, directly reflect geochemical evolution at/near the slab– mantle interface and can help us further characterize slab processes only ...
... 2003; McKenzie et al., 2004; Fig. 1). In the best case, these metamorphic suites, which contain sedimentary and igneous lithologies with appropriate seafloor protoliths, directly reflect geochemical evolution at/near the slab– mantle interface and can help us further characterize slab processes only ...
Continental breakup and the onset of ultraslow seafloor spreading
... depth migration of MCS data from the seaward portion of line 1, which crosses Flemish Cap (Fig. 1) and is conjugate to lines IAM-11 (Whitmarsh et al., 1996) and GP-101 (Reston et al., 1996). Flemish Cap is a roughly circular block of 30-km-thick continental crust with a velocity structure similar to ...
... depth migration of MCS data from the seaward portion of line 1, which crosses Flemish Cap (Fig. 1) and is conjugate to lines IAM-11 (Whitmarsh et al., 1996) and GP-101 (Reston et al., 1996). Flemish Cap is a roughly circular block of 30-km-thick continental crust with a velocity structure similar to ...
Behaviour of high field strength elements in subduction zones
... Hf/177Hf analyses on arc rocks from Kamchatka and the western Aleutians. The volcanic rocks of the Kamchatka region comprise compositional end members for both fluid and slab melt controlled mantle regimes, thus enabling systematic studies on the HFSE mobility at different conditions in the subarc m ...
... Hf/177Hf analyses on arc rocks from Kamchatka and the western Aleutians. The volcanic rocks of the Kamchatka region comprise compositional end members for both fluid and slab melt controlled mantle regimes, thus enabling systematic studies on the HFSE mobility at different conditions in the subarc m ...
Earth and Planetary Science
... the map of non-isostatic topography (Fig. 3d), the most prominent feature is low topography along the Mariana trench with maximum depth near the Challenger Deep. The Caroline Ridge and Caroline Islands Chain are associated with much more subdued features in the map of non-isostatic topography (Fig. ...
... the map of non-isostatic topography (Fig. 3d), the most prominent feature is low topography along the Mariana trench with maximum depth near the Challenger Deep. The Caroline Ridge and Caroline Islands Chain are associated with much more subdued features in the map of non-isostatic topography (Fig. ...
Review of Late Jurassic-early Miocene sedimentation and plate
... westward relative migration of the Klamath Mountains province, and U–Pb ages of deposition, sediment sources, and spatial locations of Jurassic and younger, detrital zirconbearing clastic rocks constrain geologic development of the northern California continental edge as follows: (1) At *175 Ma, tra ...
... westward relative migration of the Klamath Mountains province, and U–Pb ages of deposition, sediment sources, and spatial locations of Jurassic and younger, detrital zirconbearing clastic rocks constrain geologic development of the northern California continental edge as follows: (1) At *175 Ma, tra ...
A new look at the Altaids: A superorogenic complex in northern and
... are available, geology alone guided the reconstruction. For this we first estimated, on the basis of regional structure and stratigraphy, and course of surmised evolution, where the unit would fit as was done by Şengör et al. (1993) and Şengör and Natal'in (1996). Then we checked about it whether th ...
... are available, geology alone guided the reconstruction. For this we first estimated, on the basis of regional structure and stratigraphy, and course of surmised evolution, where the unit would fit as was done by Şengör et al. (1993) and Şengör and Natal'in (1996). Then we checked about it whether th ...
Outer slope faulting associated with the western Kuril and Japan
... Elongated fault escarpments on the outer slopes of the western Kuril and Japan trenches have been investigated through detailed swath bathymetric mapping. Numerous horsts and grabens formed by these escarpments were identified. Distinct N70°E linear alignment of the escarpments, parallel to the magn ...
... Elongated fault escarpments on the outer slopes of the western Kuril and Japan trenches have been investigated through detailed swath bathymetric mapping. Numerous horsts and grabens formed by these escarpments were identified. Distinct N70°E linear alignment of the escarpments, parallel to the magn ...
Igneous Rock Associations 8. Arc Magmatism II: Geo
... dense oceanic plate beneath an adjacent, less dense overriding plate (Fig. 1). This descent is characterized by a long, narrow, curvilinear trench in the ocean floor. With rare exceptions, magmas form in the mantle wedge above the subduction zone (i.e. in the overriding plate), and/or the crust. The ...
... dense oceanic plate beneath an adjacent, less dense overriding plate (Fig. 1). This descent is characterized by a long, narrow, curvilinear trench in the ocean floor. With rare exceptions, magmas form in the mantle wedge above the subduction zone (i.e. in the overriding plate), and/or the crust. The ...
Determining Slip Sense along the Sur
... Introduction Convergence along California occurred during the Cretaceous and the terrane assemblage formed represents a classic example of the convergent margin tectonic setting. The assemblage created is preserved in California today and is useful for determining the way that similar convergent ma ...
... Introduction Convergence along California occurred during the Cretaceous and the terrane assemblage formed represents a classic example of the convergent margin tectonic setting. The assemblage created is preserved in California today and is useful for determining the way that similar convergent ma ...
as PDF
... Central (MC) perfectly fits with an isometric low-velocity pattern. Similar features, although not as sharp, are located beneath the Cenozoic volcanic fields in Eastern Pyrenees, Eifel area, Bohemian and Pannonian massifs. These volcanic fields seem to be related to overheated parts of the upper man ...
... Central (MC) perfectly fits with an isometric low-velocity pattern. Similar features, although not as sharp, are located beneath the Cenozoic volcanic fields in Eastern Pyrenees, Eifel area, Bohemian and Pannonian massifs. These volcanic fields seem to be related to overheated parts of the upper man ...
Physical Processes Along Internal Boundaries In An Con
... near pluton roofs, do not allow us to interpret emplacement mechanisms of these plutons in detail. (iii) Intra-arc, younger irregularly shaped plutons emplaced into earlier magmatic bodies as well as into high-grade migmatites and paragneisses are represented by high-K granodiorites (Blatná and Červ ...
... near pluton roofs, do not allow us to interpret emplacement mechanisms of these plutons in detail. (iii) Intra-arc, younger irregularly shaped plutons emplaced into earlier magmatic bodies as well as into high-grade migmatites and paragneisses are represented by high-K granodiorites (Blatná and Červ ...
Geophysical insights into the Transition fault debate: Propagating
... On the basis of faulting mapped on seismic reflection and bathymetric data, seismicity, current plate motions, and evidence that the Yakutat block may be anomalously thick, we propose a tectonic model for Yakutat-Pacific interactions, including the often-debated Transition fault. To the east, deform ...
... On the basis of faulting mapped on seismic reflection and bathymetric data, seismicity, current plate motions, and evidence that the Yakutat block may be anomalously thick, we propose a tectonic model for Yakutat-Pacific interactions, including the often-debated Transition fault. To the east, deform ...
Fluid release from the subducted Cocos plate and partial melting of
... subduction related fluid release and melt production, magnetotelluric (MT) measurements were carried out in southern Mexico along two coast to coast profiles. The conductivity-depth distribution was obtained by simultaneous two-dimensional inversion of the transverse magnetic and transverse electric ...
... subduction related fluid release and melt production, magnetotelluric (MT) measurements were carried out in southern Mexico along two coast to coast profiles. The conductivity-depth distribution was obtained by simultaneous two-dimensional inversion of the transverse magnetic and transverse electric ...
Fluid release from the subducted Cocos plate and
... subduction related fluid release and melt production, magnetotelluric (MT) measurements were carried out in southern Mexico along two coast to coast profiles. The conductivity-depth distribution was obtained by simultaneous two-dimensional inversion of the transverse magnetic and transverse electric ...
... subduction related fluid release and melt production, magnetotelluric (MT) measurements were carried out in southern Mexico along two coast to coast profiles. The conductivity-depth distribution was obtained by simultaneous two-dimensional inversion of the transverse magnetic and transverse electric ...
Jackson and Gunnarss..
... The objectives of this paper are to review and evaluate the plate tectonic models suggested for the evolution of the Arctic Ocean based on data available up to 1988. This was done in three stages (Fig. 2). In stage III (from the present to anomaly ...
... The objectives of this paper are to review and evaluate the plate tectonic models suggested for the evolution of the Arctic Ocean based on data available up to 1988. This was done in three stages (Fig. 2). In stage III (from the present to anomaly ...
accepted manuscript
... oceanic crust within the Yarlung-Tsangpo Suture Zone, between India and Eurasia, predominantly date to the Late Jurassic or mid Cretaceous (Barremian-Aptian). The various ophiolites along strike and a hiatus in subduction-related magmatism during the Tithonian-Aptian suggest that there was at least ...
... oceanic crust within the Yarlung-Tsangpo Suture Zone, between India and Eurasia, predominantly date to the Late Jurassic or mid Cretaceous (Barremian-Aptian). The various ophiolites along strike and a hiatus in subduction-related magmatism during the Tithonian-Aptian suggest that there was at least ...
Nazca slab retreat versus compressional deformation in the central
... (1) Between 30 and 26 Ma, a major reorganization of plate dynamics in the eastern Pacific Ocean took place and the convergence rates hap been very low untill the breaking up of the Farallon plate into the Naxca and Cocos plates at ca 26 Ma. Oligocene tectonic activity is still poorly known. but it m ...
... (1) Between 30 and 26 Ma, a major reorganization of plate dynamics in the eastern Pacific Ocean took place and the convergence rates hap been very low untill the breaking up of the Farallon plate into the Naxca and Cocos plates at ca 26 Ma. Oligocene tectonic activity is still poorly known. but it m ...
Hydrocarbon basins in SE Asia: understanding why they are there
... Early Cenozoic history of Sundaland, which mainly lacks rocks of this age. Sundaland is a heterogeneous region, assembled from different continental blocks separated by oceanic sutures, in which there has been significant Mesozoic and Cenozoic deformation. It is not a ‘shield’ or ‘craton’. Beneath S ...
... Early Cenozoic history of Sundaland, which mainly lacks rocks of this age. Sundaland is a heterogeneous region, assembled from different continental blocks separated by oceanic sutures, in which there has been significant Mesozoic and Cenozoic deformation. It is not a ‘shield’ or ‘craton’. Beneath S ...
The Cretaceous and Cenozoic tectonic evolution of
... of conclusive full fit reconstructions between two conjugate continental margins. This region, as the link between the Tethys and (proto-)Pacific, is complex also because of the uncertain nature of plate boundaries that accommodated generally westward subduction of (proto-)Pacific oceanic crust bene ...
... of conclusive full fit reconstructions between two conjugate continental margins. This region, as the link between the Tethys and (proto-)Pacific, is complex also because of the uncertain nature of plate boundaries that accommodated generally westward subduction of (proto-)Pacific oceanic crust bene ...
PDF version - Western Washington University
... 5.1 Introduction Earth’s crust is primarily generated in oceanic settings via divergent and convergent margin processes. In divergent margins, the crust is ultimately recycled back into the mantle, whereas at convergent margins, the resulting island arc crust becomes the buoyant nucleus of new conti ...
... 5.1 Introduction Earth’s crust is primarily generated in oceanic settings via divergent and convergent margin processes. In divergent margins, the crust is ultimately recycled back into the mantle, whereas at convergent margins, the resulting island arc crust becomes the buoyant nucleus of new conti ...
Izu-Bonin-Mariana Arc
The Izu-Bonin-Mariana (IBM) arc system is an outstanding example of a plate tectonic convergent boundary. IBM extends over 2800 km south from Tokyo, Japan, to beyond Guam, and includes the Izu Islands, Bonin Islands, and Mariana Islands; much more of the IBM arc system is submerged below sealevel. The IBM arc system lies along the eastern margin of the Philippine Sea Plate in the Western Pacific Ocean. It is most famous for being the site of the deepest gash in Earth's solid surface, the Challenger Deep in the Mariana Trench. The IBM arc system formed as a result of subduction of the western Pacific plate. The IBM arc system now subducts mid-Jurassic to Early Cretaceous lithosphere, with younger lithosphere in the north and older lithosphere in the south, including the oldest (~170 million years old, or Ma) oceanic crust. Subduction rates vary from ~2 cm (1 inch) per year in the south to 6 cm (~2.5 inches) in the north. The volcanic islands that comprise these island arcs are thought to have been formed from the release of volatiles (steam from trapped water, and other gases) being released from the subducted plate, as it reached sufficient depth for the temperature to cause release of these materials. The associated trenches are formed as the oldest (most western) part of the Pacific plate crust increases in density with age, and because of this process finally reaches its lowest point just as it subducts under the crust to the west of it.The IBM arc system is an excellent example of an intra-oceanic convergent margin (IOCM). IOCMs are built on oceanic crust and contrast fundamentally with island arc built on continental crust, such as Japan or the Andes. Because IOCM crust is thinner, denser, and more refractory than that beneath Andean-type margins, study of IOCM melts and fluids allows more confident assessment of mantle-to-crust fluxes and processes than is possible for Andean-type convergent margins. Because IOCMs are far removed from continents they are not affected by the large volume of alluvial and glacial sediments. The consequent thin sedimentary cover makes it much easier to study arc infrastructure and determine the mass and composition of subducted sediments. Active hydrothermal systems found on the submarine parts of IOCMs give us a chance to study how many of earth's important ore deposits formed.