Future accreted terranes: a compilation of island arcs, oceanic
... Canada where the Paleozoic Quesnellia, Stikinia, and Cache Creek terranes were thrust and subsequently transported hundreds of kilometers inland over a Proterozoic metasedimentary wedge (Snyder et al., 2009; van der Velden and Cook, 2005; Cook et al., 2004). Other notable examples of accretion via f ...
... Canada where the Paleozoic Quesnellia, Stikinia, and Cache Creek terranes were thrust and subsequently transported hundreds of kilometers inland over a Proterozoic metasedimentary wedge (Snyder et al., 2009; van der Velden and Cook, 2005; Cook et al., 2004). Other notable examples of accretion via f ...
Building and Destroying Continental Mantle - Cin
... The interiors of continents are cored by cratons (kratos is Greek for strength), regions of crustal basement that have not been deformed for >∼1 Ga. Thus, cratons include Archean and Proterozoic basements (see Goodwin 1991 and Hoffman 1989). Figure 1 shows the distribution of Precambrian (>540 Ma) c ...
... The interiors of continents are cored by cratons (kratos is Greek for strength), regions of crustal basement that have not been deformed for >∼1 Ga. Thus, cratons include Archean and Proterozoic basements (see Goodwin 1991 and Hoffman 1989). Figure 1 shows the distribution of Precambrian (>540 Ma) c ...
What is the meaning of ophiolites? - Creation Ministries International
... mystified: ‘The emplacement of oceanic lithosphere [crust and upper mantle] onto continents remains one of the great mysteries of plate tectonics—how does ophiolitic material with a density of 3.0–3.3 g/cm3 rise from its natural depths of ≥2.5 km beneath the ocean surface to elevations more than 1 k ...
... mystified: ‘The emplacement of oceanic lithosphere [crust and upper mantle] onto continents remains one of the great mysteries of plate tectonics—how does ophiolitic material with a density of 3.0–3.3 g/cm3 rise from its natural depths of ≥2.5 km beneath the ocean surface to elevations more than 1 k ...
Volcanic activity before and after large tectonic
... literature include events that took place simultaneously as well as events separated by a considerable delay, thus of seconds, days, months or even years. While historical information on the timing of large earthquakes is often very precise, descriptions of volcanic eruptions or other activity chang ...
... literature include events that took place simultaneously as well as events separated by a considerable delay, thus of seconds, days, months or even years. While historical information on the timing of large earthquakes is often very precise, descriptions of volcanic eruptions or other activity chang ...
GEOPHYSICAL CHARACTERISTICS OF THE NINETYEAST RIDGE
... Nicobar deep east of the Andaman Nicobar Ridge, forearc basin, inner volcanic arc and the Andaman backarc basin (see Fig.1). NER is a major aseismic ridge, which extends from 30°S northwards into the Bay of Bengal where it is buried beneath the Bengal fan sediments. The ridge forms the eastern limit ...
... Nicobar deep east of the Andaman Nicobar Ridge, forearc basin, inner volcanic arc and the Andaman backarc basin (see Fig.1). NER is a major aseismic ridge, which extends from 30°S northwards into the Bay of Bengal where it is buried beneath the Bengal fan sediments. The ridge forms the eastern limit ...
Horizontal thermal contraction of oceanic lithosphere: The ultimate
... in horizontal deviatoric tension (Figure 1), which is confirmed by earthquake mechanisms [Wiens and Stein, 1984; Bergman and Solomon, 1984; Wessel, 1992]. That the upper lithosphere contracts is further supported by the agreement of geoid anomalies across the Clarion and Udintsev fracture zones with ...
... in horizontal deviatoric tension (Figure 1), which is confirmed by earthquake mechanisms [Wiens and Stein, 1984; Bergman and Solomon, 1984; Wessel, 1992]. That the upper lithosphere contracts is further supported by the agreement of geoid anomalies across the Clarion and Udintsev fracture zones with ...
Papers presented to the Conference on Heat and Detachment in
... ages indicate that ductile deformation continued as late as Oligocene (Anderson and others, 1980; Silver and Anderson, 1984). The consistency of the deformational style is such that, although considerable variation in intensity exists, the fabric can be recognized and correlated in rocks away from t ...
... ages indicate that ductile deformation continued as late as Oligocene (Anderson and others, 1980; Silver and Anderson, 1984). The consistency of the deformational style is such that, although considerable variation in intensity exists, the fabric can be recognized and correlated in rocks away from t ...
The evolution of the martian elastic lithosphere and implications for
... al., 2007) to around 70 km in the Amazonian period (McGovern et al., 2004; Belleguic et al., 2005) and this general trend is well understood in terms of planetary cooling as predicted by thermal evolution models (Hauck and Phillips, 2002; Schumacher and Breuer, 2006). However, the data also implies ...
... al., 2007) to around 70 km in the Amazonian period (McGovern et al., 2004; Belleguic et al., 2005) and this general trend is well understood in terms of planetary cooling as predicted by thermal evolution models (Hauck and Phillips, 2002; Schumacher and Breuer, 2006). However, the data also implies ...
Geothermal gradients in continental magmatic arcs: Constraints from
... and lower crust of these terranes. We then use two-dimensional numerical models to investigate the validity of the proposed mid-crustal geothermal gradient and conclude by discussing the geotherm’s implications for seismic velocity, structural, and thermochronologic data from continental arc terrane ...
... and lower crust of these terranes. We then use two-dimensional numerical models to investigate the validity of the proposed mid-crustal geothermal gradient and conclude by discussing the geotherm’s implications for seismic velocity, structural, and thermochronologic data from continental arc terrane ...
Becker, T. W. - The University of Texas at Austin
... We constrain maximum positive topography residuals, and find that those coincide with a regional maximum of seismic anisotropy and offsets in the crust and lithosphere thickness along the margins of the High Atlas and the central Middle Atlas. The inferred stretching axes from anisotropy are aligned ...
... We constrain maximum positive topography residuals, and find that those coincide with a regional maximum of seismic anisotropy and offsets in the crust and lithosphere thickness along the margins of the High Atlas and the central Middle Atlas. The inferred stretching axes from anisotropy are aligned ...
Dynamic constraints on the crustal-scale rheology of the Zagros fold
... Figure 3. Simulation with intermediate crustal detachment layers. A: Initial setup as in Figure 2, but with three additional weak crustal detachment layers with 1018 Pa·s. B: Snapshots of geometry, strain rate (ε ), and vertical velocities (Vz ) at different times (t), illustrating that crustal-sca ...
... Figure 3. Simulation with intermediate crustal detachment layers. A: Initial setup as in Figure 2, but with three additional weak crustal detachment layers with 1018 Pa·s. B: Snapshots of geometry, strain rate (ε ), and vertical velocities (Vz ) at different times (t), illustrating that crustal-sca ...
Electrical conductivity as a constraint on lower mantle thermo
... Kuvshinov and Olsen, 2006; Velímský, 2010; Civet et al., 2015; Puethe et al., 2015) that show an increase by 2 to 3 orders of magnitude between the top of the mantle and the core-mantle boundary. Regional and global tomographic models of mantle electrical conductivity have also been obtained (Kelber ...
... Kuvshinov and Olsen, 2006; Velímský, 2010; Civet et al., 2015; Puethe et al., 2015) that show an increase by 2 to 3 orders of magnitude between the top of the mantle and the core-mantle boundary. Regional and global tomographic models of mantle electrical conductivity have also been obtained (Kelber ...
Constraints on the mechanism of long
... Fig. 1. Maps showing geologic features and geodetic networks in the MLV region. (A) Location map showing general tectonic provinces of northern California and relative motions (modified from Wells et al., 1998) including the San Andreas Fault (SAF, red region), Basin and Range (B & R, yellow region) ...
... Fig. 1. Maps showing geologic features and geodetic networks in the MLV region. (A) Location map showing general tectonic provinces of northern California and relative motions (modified from Wells et al., 1998) including the San Andreas Fault (SAF, red region), Basin and Range (B & R, yellow region) ...
The Japan Trench and its juncture with the Kuril Trench" cruise
... This paper presents the results of a detailed survey combining Seabeam mapping, gravity and geomagnetic measurements as well as single-channel seismic reflection observations in the Japan Trench and the juncture with the Kuril Trench during the French-Japanese Kaiko project (northern sector of the L ...
... This paper presents the results of a detailed survey combining Seabeam mapping, gravity and geomagnetic measurements as well as single-channel seismic reflection observations in the Japan Trench and the juncture with the Kuril Trench during the French-Japanese Kaiko project (northern sector of the L ...
OCR Document
... Climate change is the long-term variability associated with the earth–ocean–climate system. The variability is caused by changes in certain boundary conditions, such as intensity of sunlight, arrangement of continents and oceans, and the composition of the atmosphere. Therefore, associated with the ...
... Climate change is the long-term variability associated with the earth–ocean–climate system. The variability is caused by changes in certain boundary conditions, such as intensity of sunlight, arrangement of continents and oceans, and the composition of the atmosphere. Therefore, associated with the ...
Target-oriented full waveform inversion of seismic data
... The linear forward modeling algorithm used for this project calculates a seismic response in the (sx , τ ) domain, where sx is the horizontal slowness and τ is the two-way traveltime of a plane-wave through the medium. Slowness is defined as the inverse of p-wave velocity ( v1p ) and the horizontal s ...
... The linear forward modeling algorithm used for this project calculates a seismic response in the (sx , τ ) domain, where sx is the horizontal slowness and τ is the two-way traveltime of a plane-wave through the medium. Slowness is defined as the inverse of p-wave velocity ( v1p ) and the horizontal s ...
2. Geophysics and the Structure of the Lesser Antilles Forearc
... tern SEABEAM (Biju-Duval et al., 1982; Fontas et al., this volume). The former method gives continuous sonograph images of the seafloor, and the latter provides high-resolution swath mapping. Both methods were used to provide a third dimension to the cross-sectional structure shown on the seismic re ...
... tern SEABEAM (Biju-Duval et al., 1982; Fontas et al., this volume). The former method gives continuous sonograph images of the seafloor, and the latter provides high-resolution swath mapping. Both methods were used to provide a third dimension to the cross-sectional structure shown on the seismic re ...
Journal of Volcanology and Geothermal Research
... seismically image the hotspot and evaluate its kinematic properties using geodetic measurements. Seismic tomography reveals a crustal magma reservoir of 8% to 15% melt, 6 km to 16 km deep, beneath the Yellowstone caldera. An upper-mantle low-P-wave-velocity body extends vertically from 80 km to 250 ...
... seismically image the hotspot and evaluate its kinematic properties using geodetic measurements. Seismic tomography reveals a crustal magma reservoir of 8% to 15% melt, 6 km to 16 km deep, beneath the Yellowstone caldera. An upper-mantle low-P-wave-velocity body extends vertically from 80 km to 250 ...
The metamorphic evolution of the Mozambique Belt in Central
... path, dominated by decompression during final stages of exhumation. The IBC segment of the Eastern Granulites forms a ‘beta’-shaped retrograde path accompanied by strike-slip tectonics at granulite facies metamorphic conditions. We interpret this highly dynamic initial cooling stage at a particular ...
... path, dominated by decompression during final stages of exhumation. The IBC segment of the Eastern Granulites forms a ‘beta’-shaped retrograde path accompanied by strike-slip tectonics at granulite facies metamorphic conditions. We interpret this highly dynamic initial cooling stage at a particular ...
Geodynamics of the Yellowstone hotspot and mantle plume: Seismic
... seismically image the hotspot and evaluate its kinematic properties using geodetic measurements. Seismic tomography reveals a crustal magma reservoir of 8% to 15% melt, 6 km to 16 km deep, beneath the Yellowstone caldera. An upper-mantle low-P-wave-velocity body extends vertically from 80 km to 250 ...
... seismically image the hotspot and evaluate its kinematic properties using geodetic measurements. Seismic tomography reveals a crustal magma reservoir of 8% to 15% melt, 6 km to 16 km deep, beneath the Yellowstone caldera. An upper-mantle low-P-wave-velocity body extends vertically from 80 km to 250 ...
- CSIRO Publishing
... the woolly jumper and beard brigade. Favoured topics were either, seismic imaging, 3D acquisition and processing with a few case histories thrown in, or improved magnetic imaging, tomography and GPS. Hard rock versus soft rock geology. It was always a challenge to keep both parties interested at the ...
... the woolly jumper and beard brigade. Favoured topics were either, seismic imaging, 3D acquisition and processing with a few case histories thrown in, or improved magnetic imaging, tomography and GPS. Hard rock versus soft rock geology. It was always a challenge to keep both parties interested at the ...
as a PDF
... silicate slurry at the top of the core, formed by stopping and entrainment, may be able to trap metal as it joins the base of the mantle. DIS may represent a transition region between mantle and core and therefore be intermediate in density and seismic velocity. The lowermost layer of the mantle is ...
... silicate slurry at the top of the core, formed by stopping and entrainment, may be able to trap metal as it joins the base of the mantle. DIS may represent a transition region between mantle and core and therefore be intermediate in density and seismic velocity. The lowermost layer of the mantle is ...
Cenozoic magmatism in the western Ross Embayment:
... chemistry, and plume theory has been stretched to the point that at least in some instances simpler explanations can be found. This controversy should be addressed in an integrated geological framework, where the space-time evolution of magma composition can be compared to the tectonic-geodynamic ev ...
... chemistry, and plume theory has been stretched to the point that at least in some instances simpler explanations can be found. This controversy should be addressed in an integrated geological framework, where the space-time evolution of magma composition can be compared to the tectonic-geodynamic ev ...
A model to explain the various paradoxes associated with mantle
... FIG. 2. The Plate Model. High R basalts contain a component from a high 3HeyU reservoir rather than a high 3He-undegassed reservoir. Magma degasses CO2 and He at shallow depth that are partially trapped in fluid inclusions or vugs in refractory (U, Th-poor) shallow mantle, (high 3HeyU). The 3Hey4He ...
... FIG. 2. The Plate Model. High R basalts contain a component from a high 3HeyU reservoir rather than a high 3He-undegassed reservoir. Magma degasses CO2 and He at shallow depth that are partially trapped in fluid inclusions or vugs in refractory (U, Th-poor) shallow mantle, (high 3HeyU). The 3Hey4He ...
Earthscope
Earthscope is an earth science program using geological and geophysical techniques to explore the structure and evolution of the North American continent and to understand the processes controlling earthquakes and volcanoes. The project has three components: USARRAY, the Plate Boundary Observatory, and the San Andreas Fault Observatory at Depth.The project is funded by the National Science Foundation (NSF), and the data produced is publicly accessible in real-time. Organizations associated with the project include UNAVCO, the Incorporated Research Institutions for Seismology (IRIS), Stanford University, the United States Geological Survey (USGS) and National Aeronautics and Space Administration (NASA). Several international organizations also contribute to the initiative.