IODP Proposal Cover Sheet
... James Gill, University of California at Santa Cruz; [email protected]; Geochemistry ...
... James Gill, University of California at Santa Cruz; [email protected]; Geochemistry ...
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... (1) it was associated with a broad zone of very young (and hot) lithosphere during mid-Tertiary time (the Shikoku Basin); and (2) it produced thickened arc crust. Both of these features resisted subduction beneath SW Japan and should have produced indelible tectonic markers in the overriding SW Japa ...
... (1) it was associated with a broad zone of very young (and hot) lithosphere during mid-Tertiary time (the Shikoku Basin); and (2) it produced thickened arc crust. Both of these features resisted subduction beneath SW Japan and should have produced indelible tectonic markers in the overriding SW Japa ...
Timing and Tectonic Setting of Volcanogenic
... coeval and likely parts of a single arc system. The Notre Dame arc formed during three distinct periods between c. 488 and 435 Ma, with the two significant magmatic gaps believed to represent collisional events (Whalen et al., 2003). The first phase is represented by c. 488-477 Ma granodiorite to di ...
... coeval and likely parts of a single arc system. The Notre Dame arc formed during three distinct periods between c. 488 and 435 Ma, with the two significant magmatic gaps believed to represent collisional events (Whalen et al., 2003). The first phase is represented by c. 488-477 Ma granodiorite to di ...
East Java: Cenozoic Basins, Volcanoes and Ancient Basement
... ash layers and pumice. Indeed, volcanic material is present in all of the younger sequences on land in East Java. U-Pb SHRIMP dating of zircons separated from sedimentary and volcanic rocks has been used in this study to identify the timing of volcanic activity in the Southern Mountains Arc. The age ...
... ash layers and pumice. Indeed, volcanic material is present in all of the younger sequences on land in East Java. U-Pb SHRIMP dating of zircons separated from sedimentary and volcanic rocks has been used in this study to identify the timing of volcanic activity in the Southern Mountains Arc. The age ...
Kimberlites and the start of plate tectonics
... oceanic lithosphere in subduction zones that subduction before ca. 1 Ga. The flux of water to powers plate motions. Although subduction the mantle was low, mostly delivered by delamizones are not part of the formal definition of PT, nation and lithospheric drips, so fluid pressure we now know that c ...
... oceanic lithosphere in subduction zones that subduction before ca. 1 Ga. The flux of water to powers plate motions. Although subduction the mantle was low, mostly delivered by delamizones are not part of the formal definition of PT, nation and lithospheric drips, so fluid pressure we now know that c ...
A multiphase seismic investigation of the shallow subduction zone
... The seismic velocities and depths of the five layers are parametrized in terms of 2-D B-splines. The B-spline functions are expressed as a linear combination of B-spline basis functions (Powell 1991) and interpolate between knot points of specified layer depth to form surfaces approximating the laye ...
... The seismic velocities and depths of the five layers are parametrized in terms of 2-D B-splines. The B-spline functions are expressed as a linear combination of B-spline basis functions (Powell 1991) and interpolate between knot points of specified layer depth to form surfaces approximating the laye ...
5. Structure of the Outer Izu-Bonin Forearc from Seismic
... 1982), large accretionary prisms have formed. However, there is little sediment in the Izu-Bonin Trench, so the Izu-Bonin arc has only a small accretionary wedge (Horine et al., 1988). Accretion and erosion are mechanical interactions. Chemical interactions, such as those produced by dewatering of t ...
... 1982), large accretionary prisms have formed. However, there is little sediment in the Izu-Bonin Trench, so the Izu-Bonin arc has only a small accretionary wedge (Horine et al., 1988). Accretion and erosion are mechanical interactions. Chemical interactions, such as those produced by dewatering of t ...
Constraints on the composition of the Aleutian arc lower crust from
... rates with respect to North American shown with yellow dotted lines, arrows and text [DeMets et al., 2010]. directly beneath the active arc [Holbrook et al., 1999] to 7.3–7.6 km/s slightly trenchward [Shillington et al., 2004]. There is a sharp step in velocity at the top of the lower crust (~0.4 km ...
... rates with respect to North American shown with yellow dotted lines, arrows and text [DeMets et al., 2010]. directly beneath the active arc [Holbrook et al., 1999] to 7.3–7.6 km/s slightly trenchward [Shillington et al., 2004]. There is a sharp step in velocity at the top of the lower crust (~0.4 km ...
Crustal structure transition from oceanic arc to continental arc
... of 350³C, roughly the temperature di¡erence between an average- and a high-heat-£ow province at 30 km depth [32]; but it is unlikely that strong horizontal temperature gradients can be maintained for a long time so compositional di¡erences must play a role as well. We have chosen not to smooth our ¢ ...
... of 350³C, roughly the temperature di¡erence between an average- and a high-heat-£ow province at 30 km depth [32]; but it is unlikely that strong horizontal temperature gradients can be maintained for a long time so compositional di¡erences must play a role as well. We have chosen not to smooth our ¢ ...
1 The role of the mantle wedge in subduction zone dynamics and
... Subduction zones are the dominant tectonic features of the Earth. They form the location of the major underthrusting earthquakes, explosive arc volcanism and are the only sites of deep earthquakes in the Earth’s mantle. The role of subduction zones in the plate tectonic framework is reasonably well ...
... Subduction zones are the dominant tectonic features of the Earth. They form the location of the major underthrusting earthquakes, explosive arc volcanism and are the only sites of deep earthquakes in the Earth’s mantle. The role of subduction zones in the plate tectonic framework is reasonably well ...
Constraints on the composition of the Aleutian arc lower crust from
... rates with respect to North American shown with yellow dotted lines, arrows and text [DeMets et al., 2010]. directly beneath the active arc [Holbrook et al., 1999] to 7.3–7.6 km/s slightly trenchward [Shillington et al., 2004]. There is a sharp step in velocity at the top of the lower crust (~0.4 km ...
... rates with respect to North American shown with yellow dotted lines, arrows and text [DeMets et al., 2010]. directly beneath the active arc [Holbrook et al., 1999] to 7.3–7.6 km/s slightly trenchward [Shillington et al., 2004]. There is a sharp step in velocity at the top of the lower crust (~0.4 km ...
Mantle temperature control on composition of arc magmas along the
... ftp://ftp.ifm-geomar.de/users/mportnyagin/ Kamchatka. A distinctive feature of the CKD volcanoes compared to other volcanoes in Kamchatka is the presence of primitive rocks with Mg# > 0.65 (Mg# = MgO/(MgO + FeO*) calculated on a molar basis, where FeO* is total Fe expressed as FeO, approaching compo ...
... ftp://ftp.ifm-geomar.de/users/mportnyagin/ Kamchatka. A distinctive feature of the CKD volcanoes compared to other volcanoes in Kamchatka is the presence of primitive rocks with Mg# > 0.65 (Mg# = MgO/(MgO + FeO*) calculated on a molar basis, where FeO* is total Fe expressed as FeO, approaching compo ...
IODP Proposal Cover Sheet
... et al., unpublished data). In addition, Yamazaki & Yuasa (1998) reported three conspicuous north-south rows of long-wavelength magnetic anomalies in the Izu-Bonin arc, which are slightly oblique to the present volcanic front. The eastern row correlates with the frontal arc highs, the western row coi ...
... et al., unpublished data). In addition, Yamazaki & Yuasa (1998) reported three conspicuous north-south rows of long-wavelength magnetic anomalies in the Izu-Bonin arc, which are slightly oblique to the present volcanic front. The eastern row correlates with the frontal arc highs, the western row coi ...
The role of magmatically driven lithospheric thickening on arc front
... descends into the Earth’s deep interior. Arc volcanism forms one of the primary connections between longterm climate, landscape, and mantle dynamics. For example, convergent margin igneous activity is one of the main drivers of crustal differentiation and the formation of continents. Arc volcanoes c ...
... descends into the Earth’s deep interior. Arc volcanism forms one of the primary connections between longterm climate, landscape, and mantle dynamics. For example, convergent margin igneous activity is one of the main drivers of crustal differentiation and the formation of continents. Arc volcanoes c ...
P corner, Japan-Kurile arc-arc junction Kei Katsumata, Naoto Wada, and Minoru Kasahara
... corner. The Kurile Islands arc is moving toward the southwest at a speed of 6–11 mm/year relative to the North American plate (DeMets, 1992) and has been colliding against the northeastern Japan arc since middle Miocene, forming the arc-arc type Hidaka collision zone (HCZ) in and around the Hokkaido ...
... corner. The Kurile Islands arc is moving toward the southwest at a speed of 6–11 mm/year relative to the North American plate (DeMets, 1992) and has been colliding against the northeastern Japan arc since middle Miocene, forming the arc-arc type Hidaka collision zone (HCZ) in and around the Hokkaido ...
Crust-mantle structures and Neogene
... pressures at different levels of the crust was stated in the Tuscan geothermal province from the integrated analysis of the seismic data (Accaino et al., 2004). The interpretations, supported by seismic prospecting methods different both for penetration and resolution, have confirmed that the lithos ...
... pressures at different levels of the crust was stated in the Tuscan geothermal province from the integrated analysis of the seismic data (Accaino et al., 2004). The interpretations, supported by seismic prospecting methods different both for penetration and resolution, have confirmed that the lithos ...
C 2 = C 1 + h
... Pro- and retrograde metamorphic reactions play important roles for the dynamics in orogenic belts in that they give • Changes in petrophysical properties (density structure and hence evolution of topography) • Reaction enhanced deformation (increased strain (strain-rate) in zones of reaction) • Mate ...
... Pro- and retrograde metamorphic reactions play important roles for the dynamics in orogenic belts in that they give • Changes in petrophysical properties (density structure and hence evolution of topography) • Reaction enhanced deformation (increased strain (strain-rate) in zones of reaction) • Mate ...
Chapter 11 SEDIMENTARY BASINS
... 7.1 The concept of geosynclines was developed in the last century to deal with the existence of thick successions of sedimentary rocks in what we would today call orogenic belts. A geosyncline is large troughlike or basinlike downwarping of the crust in which thick sedimentary and volcanic rocks acc ...
... 7.1 The concept of geosynclines was developed in the last century to deal with the existence of thick successions of sedimentary rocks in what we would today call orogenic belts. A geosyncline is large troughlike or basinlike downwarping of the crust in which thick sedimentary and volcanic rocks acc ...
Slide 1
... surprisingly similar to many modern arcs whose seismic velocity structures have been determined (IBM, Tonga, Kurile, Aleutians, North Honshu, Cascades). In all of these modern arcs, an upper mid-crust with Vp 6.0-6.5 km/s is present, corresponding to velocities calculated for exhumed arc upper mid-c ...
... surprisingly similar to many modern arcs whose seismic velocity structures have been determined (IBM, Tonga, Kurile, Aleutians, North Honshu, Cascades). In all of these modern arcs, an upper mid-crust with Vp 6.0-6.5 km/s is present, corresponding to velocities calculated for exhumed arc upper mid-c ...
Back Arc Extension in the Okinawa Trough
... with normal faulting of the initially adjacent Ryukyu nonvolcanic arc and the Taiwan-Sinzi folded belt, corresponds to the first rifting phase. The timing of rifting is supported by the presence of marine sedimentsof corresponding age drilled in the northern Okinawa Trough. The rifting occurred afte ...
... with normal faulting of the initially adjacent Ryukyu nonvolcanic arc and the Taiwan-Sinzi folded belt, corresponds to the first rifting phase. The timing of rifting is supported by the presence of marine sedimentsof corresponding age drilled in the northern Okinawa Trough. The rifting occurred afte ...
Plate tectonics and lithosphere architecture: temporal and spatial
... 'stratigraphy' of the lithosphere beneath individual volcanic provinces. Lithostratigraphic variations can be (a) investigated across boundaries between major crustal age provinces, (b) studied in relation to heat flow variations, and, (c) correlated with the presence or absence of high velocity ano ...
... 'stratigraphy' of the lithosphere beneath individual volcanic provinces. Lithostratigraphic variations can be (a) investigated across boundaries between major crustal age provinces, (b) studied in relation to heat flow variations, and, (c) correlated with the presence or absence of high velocity ano ...
Activity–Pacific Northwest Tectonic Block Model
... Circle the names of the three major tectonic plates labeled on the map. 1. Which two plates are interacting at the Cascadia Subduction zone? The Juan de Fuca and the North American plates 2. Which plate is being subducted? How do you know? Answers will vary (using the key in the upper right hand c ...
... Circle the names of the three major tectonic plates labeled on the map. 1. Which two plates are interacting at the Cascadia Subduction zone? The Juan de Fuca and the North American plates 2. Which plate is being subducted? How do you know? Answers will vary (using the key in the upper right hand c ...
Twin Hotspot Tracks and Ridge Jumps
... Udo Barckhausen Federal Institute for Geosciences and Natural Resources Germany ...
... Udo Barckhausen Federal Institute for Geosciences and Natural Resources Germany ...
The Puzzling Plates – Part I
... that are part of each. If a plate contributes to more than one ocean basin, be sure to include it wherever is necessary. The layer of Earth that you have assembled is the upper mantle portion of the lithosphere. The lithosphere is comprised of the upper mantle and the overlying crust. All of the lit ...
... that are part of each. If a plate contributes to more than one ocean basin, be sure to include it wherever is necessary. The layer of Earth that you have assembled is the upper mantle portion of the lithosphere. The lithosphere is comprised of the upper mantle and the overlying crust. All of the lit ...
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.