Global geochemical variation of mid-ocean ridge basalts - UiO
... as sea floor spreading. Due to the large amount of newly emplaced lithosphere this process is responsible for the vast majority of magmatic activity on the Earth’s surface with almost the complete global volume of melt production being tied to MORs. Due to its vast geographical extent and volume mid ...
... as sea floor spreading. Due to the large amount of newly emplaced lithosphere this process is responsible for the vast majority of magmatic activity on the Earth’s surface with almost the complete global volume of melt production being tied to MORs. Due to its vast geographical extent and volume mid ...
Petrogenesis of subvolcanic rocks from the Khunik prospecting area
... hydrothermal breccia), and some contain different amounts of mineralization as disseminate, stockwork and hydrothermal breccia; 2 – granodiorite porphyry unit that is younger than mineralization, and have no mineralization and less alteration. ...
... hydrothermal breccia), and some contain different amounts of mineralization as disseminate, stockwork and hydrothermal breccia; 2 – granodiorite porphyry unit that is younger than mineralization, and have no mineralization and less alteration. ...
Origin of dipping structures in fast
... 39 800, Fig. 4) and Line 45 (CMP 32 100, Fig. 2a). Basement topography is substantially rougher for oceanic crust created at intermediate spreading rate, with variations of up to ∼800 m over distances of 1–14 km (Fig. 5a), similar to intermediate spreading crust elsewhere (e.g., Malinverno, 1991). F ...
... 39 800, Fig. 4) and Line 45 (CMP 32 100, Fig. 2a). Basement topography is substantially rougher for oceanic crust created at intermediate spreading rate, with variations of up to ∼800 m over distances of 1–14 km (Fig. 5a), similar to intermediate spreading crust elsewhere (e.g., Malinverno, 1991). F ...
Spontaneous development of arcuate single‐sided subduction in
... for the dynamics is highlighted by the fact that the sinking portions of a plate (i.e., slabs) are the main drivers of mantle convection and plate tectonics [Forsyth and Uyeda, 1975; Conrad and Lithgow-Bertelloni, 2002]. Dynamical implications of subduction zones are, however, not only limited to pl ...
... for the dynamics is highlighted by the fact that the sinking portions of a plate (i.e., slabs) are the main drivers of mantle convection and plate tectonics [Forsyth and Uyeda, 1975; Conrad and Lithgow-Bertelloni, 2002]. Dynamical implications of subduction zones are, however, not only limited to pl ...
Seismic attenuation in the Carpathian bend zone and surroundings
... the SE extreme of the high elevations at the Carpathian bend zone, and span depths from 70 to around 200 km (Fig. 1) [12,13]. The Vrancea seismicity is unusual in several respects: (1) seismicity in the zone does not define a tabular slab so much as a flattened, nearly vertical cylinder (Fig. 3). Th ...
... the SE extreme of the high elevations at the Carpathian bend zone, and span depths from 70 to around 200 km (Fig. 1) [12,13]. The Vrancea seismicity is unusual in several respects: (1) seismicity in the zone does not define a tabular slab so much as a flattened, nearly vertical cylinder (Fig. 3). Th ...
Proterozoic History
... Much of the factual information presented above was taken from these key references or from literature cited in these. Dalziel I. W. D. (1997). Neoproterozoic-Paleozoic geography and tectonics: review, hypothesis, and environmental speculation. Geological Society of America Bulletin, 109, 16–42. [A ...
... Much of the factual information presented above was taken from these key references or from literature cited in these. Dalziel I. W. D. (1997). Neoproterozoic-Paleozoic geography and tectonics: review, hypothesis, and environmental speculation. Geological Society of America Bulletin, 109, 16–42. [A ...
a post-Gravity Recovery and Interior Laboratory reassessment
... between 32 and 45 km, with a best fit value of 40 km. This study also provided seismically determined crustal thickness estimates at numerous meteoroid impact locations and provided revised crustal thicknesses at the Apollo 12, 14, 15 and 16 sites of 33 ± 5, 31 ± 7, 35 ± 8 and 38 ± 7 km, respectivel ...
... between 32 and 45 km, with a best fit value of 40 km. This study also provided seismically determined crustal thickness estimates at numerous meteoroid impact locations and provided revised crustal thicknesses at the Apollo 12, 14, 15 and 16 sites of 33 ± 5, 31 ± 7, 35 ± 8 and 38 ± 7 km, respectivel ...
Calculating plate movement and plate motion activity File
... we've measured using GPS and other surveying techniques compare with those estimated over the millions of years of geologic time? To do this, we'll look at the relative motion between North America and Africa. Hopefully, you've discovered that North America and Africa are currently moving apart from ...
... we've measured using GPS and other surveying techniques compare with those estimated over the millions of years of geologic time? To do this, we'll look at the relative motion between North America and Africa. Hopefully, you've discovered that North America and Africa are currently moving apart from ...
Introduction - Beck-Shop
... Alternative models for crustal growth place greater importance on basaltic magmatism related to superplume events and the accretion of oceanic plateaus to continents. Oceanic plateaus cover about 3% of modern Earth’s sea floor, and if the Ontong Java Plateau collision with the Solomon Islands Arc is ...
... Alternative models for crustal growth place greater importance on basaltic magmatism related to superplume events and the accretion of oceanic plateaus to continents. Oceanic plateaus cover about 3% of modern Earth’s sea floor, and if the Ontong Java Plateau collision with the Solomon Islands Arc is ...
Initiation of plate boundary slip in the Nankai Trough off the Muroto
... the SOM classification boundary described above (Figure 4a). Site 808 is located 1.7 km landward of the proto-thrust and on the landward side of the SOM classification boundary. At Site 1174, the porosity of the décollement measured from core samples changes little across the décollement by compar ...
... the SOM classification boundary described above (Figure 4a). Site 808 is located 1.7 km landward of the proto-thrust and on the landward side of the SOM classification boundary. At Site 1174, the porosity of the décollement measured from core samples changes little across the décollement by compar ...
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... magmatic activity. Subsequent to initial alkaline magmatism, localized mid-oceanic ridge basalts (MORB) magmatism was again replaced by basin-wide alkaline events, caused by a low degree of decompression melting due to tectonic delocalization of deformation. Such “off-axis” magmatism might be a comm ...
... magmatic activity. Subsequent to initial alkaline magmatism, localized mid-oceanic ridge basalts (MORB) magmatism was again replaced by basin-wide alkaline events, caused by a low degree of decompression melting due to tectonic delocalization of deformation. Such “off-axis” magmatism might be a comm ...
On Earth`s Mantle Constitution and Structure from Joint Analysis of
... and bulk composition. For this purpose we use the thermodynamic formulation of Stixrude and Lithgow-Bertelloni (2005) with parameters as in Stixrude and Lithgow-Bertelloni (2011). Although Gibbs energy minimization has long been advocated for geophysical problems (e.g., Sobolev and Babeyko 1994; Bin ...
... and bulk composition. For this purpose we use the thermodynamic formulation of Stixrude and Lithgow-Bertelloni (2005) with parameters as in Stixrude and Lithgow-Bertelloni (2011). Although Gibbs energy minimization has long been advocated for geophysical problems (e.g., Sobolev and Babeyko 1994; Bin ...
The role of crustal quartz in controlling Cordilleran
... deformation zones ranging from tens to thousands of kilometres in width, why deforming zones are sometimes interspersed with non-deforming blocks and why large earthquakes occasionally rupture in otherwise stable continental interiors. An important clue comes from observations that mountain belts an ...
... deformation zones ranging from tens to thousands of kilometres in width, why deforming zones are sometimes interspersed with non-deforming blocks and why large earthquakes occasionally rupture in otherwise stable continental interiors. An important clue comes from observations that mountain belts an ...
Seismic Refraction / Reflection
... surveys are used to map, detect, & delineate geologic conditions including the bedrock surface, voids, water table and layer geometry (folds). The Seismic Refraction & Reflection (SRR) system is designed to allow for either seismic refraction or seismic reflection data acquisition. The SRR system, w ...
... surveys are used to map, detect, & delineate geologic conditions including the bedrock surface, voids, water table and layer geometry (folds). The Seismic Refraction & Reflection (SRR) system is designed to allow for either seismic refraction or seismic reflection data acquisition. The SRR system, w ...
Geo-neutrinos and Earth`s interior
... regard mostly the crust and an undetermined portion of the mantle. The global abundance of no element in the Earth can be estimated on the basis of observational data only. Geo-neutrinos could provide the first direct test of BSE (and/or its variants) by measuring the global abundances of natural he ...
... regard mostly the crust and an undetermined portion of the mantle. The global abundance of no element in the Earth can be estimated on the basis of observational data only. Geo-neutrinos could provide the first direct test of BSE (and/or its variants) by measuring the global abundances of natural he ...
Figure 1 - ePrints Soton - University of Southampton
... comprise solely products of partial melting. The remarkable consistency of seismic velocities in layer 3, the lower oceanic crust, was apparent in early compilations of results from seismic refraction profiles (Raitt, 1963), and remains true even after the addition of many more seismic results, and ...
... comprise solely products of partial melting. The remarkable consistency of seismic velocities in layer 3, the lower oceanic crust, was apparent in early compilations of results from seismic refraction profiles (Raitt, 1963), and remains true even after the addition of many more seismic results, and ...
No Slide Title
... Virtually all magmas generated within outer 250 km of the Earth by melting solid mineral assemblages. Magmas form in three main regions: • In the Mantle beneath Oceanic Spreading Ridges. Oceanic Crust under tension, pulls apart, and magma rises in response to convection cell heating. • At Conver ...
... Virtually all magmas generated within outer 250 km of the Earth by melting solid mineral assemblages. Magmas form in three main regions: • In the Mantle beneath Oceanic Spreading Ridges. Oceanic Crust under tension, pulls apart, and magma rises in response to convection cell heating. • At Conver ...
Imaging the lithospheric structure beneath the Indian continent
... Abstract We present a high-resolution 3-D lithospheric model of the Indian plate region down to 300 km depth, obtained by inverting a new massive database of surface wave observations, using classical tomographic methods. Data are collected from more than 550 seismic broadband stations spanning the ...
... Abstract We present a high-resolution 3-D lithospheric model of the Indian plate region down to 300 km depth, obtained by inverting a new massive database of surface wave observations, using classical tomographic methods. Data are collected from more than 550 seismic broadband stations spanning the ...
Tectonophysics_2009_Crustal and upper mantle velocity
... 1986; Lin et al., 1993). The average P-wave velocity of the crust is about 6.2 km/s and its thickness varies between approximately 58 km under the northern part of Yunnan and 32 km beneath its southern border. A feature that should be emphasized is the existence of a 10 km-thick low velocity layer ...
... 1986; Lin et al., 1993). The average P-wave velocity of the crust is about 6.2 km/s and its thickness varies between approximately 58 km under the northern part of Yunnan and 32 km beneath its southern border. A feature that should be emphasized is the existence of a 10 km-thick low velocity layer ...
Folie 1
... Koch, M., 1993:. Simultaneous inversion for 3D crustal structure and hypocenters including direct, refracted and reflected phases. I. Development, Validation and optimal regularization of the method, Geophys. J. Int., 112 ,385–412. Song, L-P., Koch, M., Koch, K., Schlittenhardt, J., 2001 : Isotropic ...
... Koch, M., 1993:. Simultaneous inversion for 3D crustal structure and hypocenters including direct, refracted and reflected phases. I. Development, Validation and optimal regularization of the method, Geophys. J. Int., 112 ,385–412. Song, L-P., Koch, M., Koch, K., Schlittenhardt, J., 2001 : Isotropic ...
Petrogenesis of the Eocene and Mio–Pliocene alkaline basaltic
... subduction of different lithospheric plates and various oceanic spreading ridges (e.g. Cande and Leslie, 1986). In particular, oblique subduction of the South Chile spreading Ridge (SCR) beneath the South American plate began 14–15 Ma ago when a segment of the ridge collided with the Chile Trench ne ...
... subduction of different lithospheric plates and various oceanic spreading ridges (e.g. Cande and Leslie, 1986). In particular, oblique subduction of the South Chile spreading Ridge (SCR) beneath the South American plate began 14–15 Ma ago when a segment of the ridge collided with the Chile Trench ne ...
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.