Whole-mantle convection and plate tectonics
... The idea of whole-mantle convection is certainly not new ( e g Holmes 1931; Pekeris 1935; Hales 1936; Griggs 1939; Hess 1962; Vening Meinesz 1947; Runcorn 1962, 1972; Wilson 1963; Tozer 1972), although it has always been controversial. Before and during the time that the theory of plate tectonics wa ...
... The idea of whole-mantle convection is certainly not new ( e g Holmes 1931; Pekeris 1935; Hales 1936; Griggs 1939; Hess 1962; Vening Meinesz 1947; Runcorn 1962, 1972; Wilson 1963; Tozer 1972), although it has always been controversial. Before and during the time that the theory of plate tectonics wa ...
Reconstructing the Alps–Carpathians–Dinarides as a key to
... been galvanized in the past decade by teleseismic tomographic images of two positive compressive-wave velocity (+Vp) slab anomalies with contrasting orientations beneath the Alps (Fig. 4a–c): one beneath the Central and Western Alps that dips to the southeast to a depth of about 200 km and is consis ...
... been galvanized in the past decade by teleseismic tomographic images of two positive compressive-wave velocity (+Vp) slab anomalies with contrasting orientations beneath the Alps (Fig. 4a–c): one beneath the Central and Western Alps that dips to the southeast to a depth of about 200 km and is consis ...
vauchez_etal_rheology_1998_hal
... composition and rheological parameters over its entire thickness (Fig. 1). The strength of rocks at a given depth D depends on temperature .TD /, pressure .PD /, deformation mechanism dominant at TD and PD , and strain rate. In a simplified approach, two main mechanisms are competing: brittle failur ...
... composition and rheological parameters over its entire thickness (Fig. 1). The strength of rocks at a given depth D depends on temperature .TD /, pressure .PD /, deformation mechanism dominant at TD and PD , and strain rate. In a simplified approach, two main mechanisms are competing: brittle failur ...
Rheological heterogeneity, mechanical anisotropy and
... composition and rheological parameters over its entire thickness (Fig. 1). The strength of rocks at a given depth D depends on temperature .TD /, pressure .PD /, deformation mechanism dominant at TD and PD , and strain rate. In a simplified approach, two main mechanisms are competing: brittle failur ...
... composition and rheological parameters over its entire thickness (Fig. 1). The strength of rocks at a given depth D depends on temperature .TD /, pressure .PD /, deformation mechanism dominant at TD and PD , and strain rate. In a simplified approach, two main mechanisms are competing: brittle failur ...
Characteristic thermal regimes of plate tectonics
... belts in the rock record registers contemporary sites of high heat flow, inferred to be similar to modern arcs, abd backarcs, or orogenic hinterlands, where more extreme temperatures were imposed on crustal rocks than previously recorded. Blueschists first became evident in the Neoproterozoic rock r ...
... belts in the rock record registers contemporary sites of high heat flow, inferred to be similar to modern arcs, abd backarcs, or orogenic hinterlands, where more extreme temperatures were imposed on crustal rocks than previously recorded. Blueschists first became evident in the Neoproterozoic rock r ...
Caribbean Basins - Red Cubana de la Ciencia
... rocks exposed on the island of Hispaniola may represent the continuation of the Grenada and Yucatfin back-arc basins in this area (Fig. 2). Deformation of Caribbean crust and basin formation ...
... rocks exposed on the island of Hispaniola may represent the continuation of the Grenada and Yucatfin back-arc basins in this area (Fig. 2). Deformation of Caribbean crust and basin formation ...
Mantle discontinuities beneath the Deccan volcanic
... velocity zone below 200 km were mapped through teleseismic P-wave tomography [14]. This seismic anomaly is seen to link to the Narmada rift and possibly extends further south beneath the Western Ghats, the main effusive phase in the DVP, where the tomograms were not well resolved. Earlier, tomograph ...
... velocity zone below 200 km were mapped through teleseismic P-wave tomography [14]. This seismic anomaly is seen to link to the Narmada rift and possibly extends further south beneath the Western Ghats, the main effusive phase in the DVP, where the tomograms were not well resolved. Earlier, tomograph ...
as a PDF
... et al. (2004) and Walcott (1998) argued that the lack of geological evidence for large Cenozoic faults does not support large-magnitude, regional extension in much of the region. According to Rocchi et al. (2003) and Wilson (1995), the Transantarctic Mountains front, as well as offshore faults and f ...
... et al. (2004) and Walcott (1998) argued that the lack of geological evidence for large Cenozoic faults does not support large-magnitude, regional extension in much of the region. According to Rocchi et al. (2003) and Wilson (1995), the Transantarctic Mountains front, as well as offshore faults and f ...
Alignment between seafloor spreading directions and absolute plate
... seafloor, consistent with the findings of Becker et al. [2015]. Median skew values (Figure 3) for the last 20 Myr are typically <20° in the Pacific for all APM models and between 10 and 40° for spreading in the Indian and Atlantic domains. Over the last 130 Myr, the time-dependent histograms illustrate ...
... seafloor, consistent with the findings of Becker et al. [2015]. Median skew values (Figure 3) for the last 20 Myr are typically <20° in the Pacific for all APM models and between 10 and 40° for spreading in the Indian and Atlantic domains. Over the last 130 Myr, the time-dependent histograms illustrate ...
Geodynamical interpretation of crustal and upper mantle electrical conductivity
... There exists a number of models that account for the deep structure of the Sayan-Baikal province on the basis of different geophysical data. The models based on magnetotelluric soundings differ from those obtained from seismology with no regard to magnetotelluric soundings (MTS) results. To decide b ...
... There exists a number of models that account for the deep structure of the Sayan-Baikal province on the basis of different geophysical data. The models based on magnetotelluric soundings differ from those obtained from seismology with no regard to magnetotelluric soundings (MTS) results. To decide b ...
Pacific slab pull and intraplate deformation
... configurations, subducting slab geometries, and absolute plate motion is poorly understood. We utilise a buoyancy driven Stokes flow solver, BEM-Earth, to investigate the contribution of subducting slabs through time on Pacific Plate motion and plate-scale deformation, and how this is linked to intr ...
... configurations, subducting slab geometries, and absolute plate motion is poorly understood. We utilise a buoyancy driven Stokes flow solver, BEM-Earth, to investigate the contribution of subducting slabs through time on Pacific Plate motion and plate-scale deformation, and how this is linked to intr ...
Exhumation of (ultra-)high-pressure terranes: concepts
... Abstract. The formation and exhumation of high and ultrahigh-pressure, (U)HP, rocks of crustal origin appears to be ubiquitous during Phanerozoic plate subduction and continental collision events. Exhumation of (U)HP material has been shown in some orogens to have occurred only once, during a single ...
... Abstract. The formation and exhumation of high and ultrahigh-pressure, (U)HP, rocks of crustal origin appears to be ubiquitous during Phanerozoic plate subduction and continental collision events. Exhumation of (U)HP material has been shown in some orogens to have occurred only once, during a single ...
Late Cretaceous and Paleogene tectonic evolution of
... The Late Cretaceous history of the northern Pacific Ocean has not been adequately deciphered, largely because a major plate reorganization occurred during the Cretaceous magnetic quiet interval. Using primary data to reconstruct plate motions from fracture zone trends and Late Cretaceous seafloor sp ...
... The Late Cretaceous history of the northern Pacific Ocean has not been adequately deciphered, largely because a major plate reorganization occurred during the Cretaceous magnetic quiet interval. Using primary data to reconstruct plate motions from fracture zone trends and Late Cretaceous seafloor sp ...
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 ...
Viscosity of the asthenosphere from glacial isostatic adjustment and
... of asthenospheric thicknesses, provided that the asthenospheric viscosity is varied from 3 1018 Pa s for a thin (140 km) asthenosphere to 4 1019 Pa s for a thick (380 km) asthenosphere. Present-day vertical crustal motion predicted by the GIA models shows rates of a few tenths of a millimeter pe ...
... of asthenospheric thicknesses, provided that the asthenospheric viscosity is varied from 3 1018 Pa s for a thin (140 km) asthenosphere to 4 1019 Pa s for a thick (380 km) asthenosphere. Present-day vertical crustal motion predicted by the GIA models shows rates of a few tenths of a millimeter pe ...
Proterozoic subduction-related and continental rift
... as sources of OIB magmas11. Accessory minerals, including ilmenite, sphene, rutile, zircon and apatite, which retain HFSE either in the slab or mantle wedge during partial melting, also play a significant role in imparting geochemical signatures characteristic of subduction-zone magmas14–16. However ...
... as sources of OIB magmas11. Accessory minerals, including ilmenite, sphene, rutile, zircon and apatite, which retain HFSE either in the slab or mantle wedge during partial melting, also play a significant role in imparting geochemical signatures characteristic of subduction-zone magmas14–16. However ...
2. Geology and tectonics of the Aegean - diss.fu
... Eurasian plate during the last 92 My (Müller & Kahle, 1993). The existence of a calcalkaline inner volcanic arc, the spatial distribution of earthquakes and detailed tomographic studies indicate the existence of a northward-dipping subducted slab beneath this region (African plate beneath Eurasian p ...
... Eurasian plate during the last 92 My (Müller & Kahle, 1993). The existence of a calcalkaline inner volcanic arc, the spatial distribution of earthquakes and detailed tomographic studies indicate the existence of a northward-dipping subducted slab beneath this region (African plate beneath Eurasian p ...
Earth Planet. Sci. Lett., 139, 1-16, 1996.
... west flank is 300 m shallower than the east flank. The youngest seafloor west of the SEPR is already characterized by unusual depth-age behavior even near the SEPR axis. Since the rise axis in that area is anomalously deep to start with (2625-2872 m>, there is no anomalously shallow seafloor on the ...
... west flank is 300 m shallower than the east flank. The youngest seafloor west of the SEPR is already characterized by unusual depth-age behavior even near the SEPR axis. Since the rise axis in that area is anomalously deep to start with (2625-2872 m>, there is no anomalously shallow seafloor on the ...
How Plate-forming Processes Explain Structure and Shortening in
... regions dominated by underthrusting, suggesting simple‐shear subduction of the underlying crust. Thick‐skinned styles are characteristics of regions involving deeper basement‐involved deformation where reverse reactivation of inherited discontinuities is a common geological feature, inferring pure‐s ...
... regions dominated by underthrusting, suggesting simple‐shear subduction of the underlying crust. Thick‐skinned styles are characteristics of regions involving deeper basement‐involved deformation where reverse reactivation of inherited discontinuities is a common geological feature, inferring pure‐s ...
Revised Tectonic Evolution of the Eastern Indian Ocean
... Our Euler poles (Supplementary Figure 2) fall systematically to the west of the previously published poles of Whittaker et al., (2007) and Tikku and Cande (2000). The consistent NW-SE elongation of the ellipses reflects the lack of fracture zone constraints in our computations. The least-squares app ...
... Our Euler poles (Supplementary Figure 2) fall systematically to the west of the previously published poles of Whittaker et al., (2007) and Tikku and Cande (2000). The consistent NW-SE elongation of the ellipses reflects the lack of fracture zone constraints in our computations. The least-squares app ...
Scholarly Interest Report
... motion between the Indian, Capricorn, and Somalian plates since 20 Ma: Evidence for changes coinciding with the onset of seafloor deformation in the Central Indian basin." Geophysical Journal International (in revisio) Zatman, S., R. G. Gordon, and M. A. Richards "Analytic models for the dynamics of ...
... motion between the Indian, Capricorn, and Somalian plates since 20 Ma: Evidence for changes coinciding with the onset of seafloor deformation in the Central Indian basin." Geophysical Journal International (in revisio) Zatman, S., R. G. Gordon, and M. A. Richards "Analytic models for the dynamics of ...
PDF
... Mariana Trough. They concluded that the mantle source was enriched in the order Ba > Rb > K > LREE > Sr and depleted in Y and attributed these to addition of a melt from the subducted, eclogite slab into an otherwise depleted mantle. Evidence also emerged of systematic trace element variations withi ...
... Mariana Trough. They concluded that the mantle source was enriched in the order Ba > Rb > K > LREE > Sr and depleted in Y and attributed these to addition of a melt from the subducted, eclogite slab into an otherwise depleted mantle. Evidence also emerged of systematic trace element variations withi ...
Seismic evidence for subduction-transported water in the lower mantle
... exist within the oceanic crust and lithosphere in common low-pressure hydrous silicate phases like serpentine. As the lithosphere subducts into the top of the upper mantle, serpentine becomes unstable, but not all of its water is released: some water continues downward within the slab, locked in a s ...
... exist within the oceanic crust and lithosphere in common low-pressure hydrous silicate phases like serpentine. As the lithosphere subducts into the top of the upper mantle, serpentine becomes unstable, but not all of its water is released: some water continues downward within the slab, locked in a s ...
PNG ON THE MOVE - GPS MONITORING OF PLATE TECTONICS
... Surveying and Land Studies showing some startling results from these surveys. Introduction Papua New Guinea lies in one of the most tectonically and volcanically active regions in the world, a region where the Pacific and Australian Plates collide. Within Papua New Guinea there are also several smal ...
... Surveying and Land Studies showing some startling results from these surveys. Introduction Papua New Guinea lies in one of the most tectonically and volcanically active regions in the world, a region where the Pacific and Australian Plates collide. Within Papua New Guinea there are also several smal ...
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.