A Feasibility Study of Non-Seismic Geophysical
... Inversion of gravity data is very important, since construction of density contrast models significantly increases the amount of information that can be extracted from the gravity data. However, one substantial difficulty with the inversion of gravity data is its inherent non-uniqueness and lack of ...
... Inversion of gravity data is very important, since construction of density contrast models significantly increases the amount of information that can be extracted from the gravity data. However, one substantial difficulty with the inversion of gravity data is its inherent non-uniqueness and lack of ...
Numerical models, geochemistry and the zero-paradox noble
... depleted reservoir supplies mid-ocean-ridge volcanism. In this model, plumes feed intraplate volcanism from the deep mantle and sample a more volatile-rich and less depleted portion of the mantle. The boundary between these reservoirs has often been assumed to be at a depth of 670 km, where either a ...
... depleted reservoir supplies mid-ocean-ridge volcanism. In this model, plumes feed intraplate volcanism from the deep mantle and sample a more volatile-rich and less depleted portion of the mantle. The boundary between these reservoirs has often been assumed to be at a depth of 670 km, where either a ...
Author`s personal copy
... Voluminous intermediate to silicic composition volcanic rocks were generated throughout the southern Rocky Mountains, western U.S., during the mid-Tertiary “ignimbrite flare-up”, principally at the San Juan and Mogollon-Datil volcanic fields. At both volcanic centers, radiogenic isotope data have be ...
... Voluminous intermediate to silicic composition volcanic rocks were generated throughout the southern Rocky Mountains, western U.S., during the mid-Tertiary “ignimbrite flare-up”, principally at the San Juan and Mogollon-Datil volcanic fields. At both volcanic centers, radiogenic isotope data have be ...
Cenozoic magmatism in the western Ross Embayment:
... sciences to the scientific way of thinking [Frodeman, 1995]. [3] In this paper, these issues are dealt with by a chronological-geochemical study of a prime example of longlasting magmatism associated with an extensive area of rifted crust in Antarctica, known as the West Antarctic Rift System (WARS) ...
... sciences to the scientific way of thinking [Frodeman, 1995]. [3] In this paper, these issues are dealt with by a chronological-geochemical study of a prime example of longlasting magmatism associated with an extensive area of rifted crust in Antarctica, known as the West Antarctic Rift System (WARS) ...
Sample
... Earth Science LO: 4.5 - Many active geologic processes occur at plate boundaries. 28) How did researchers in the mid-20th century obtain ocean floor samples in order to determine the age of the seafloor? A) Satellite imagine B) Manned submersibles C) Hydraulic vacuum tubes D) Drilling ships Answer: ...
... Earth Science LO: 4.5 - Many active geologic processes occur at plate boundaries. 28) How did researchers in the mid-20th century obtain ocean floor samples in order to determine the age of the seafloor? A) Satellite imagine B) Manned submersibles C) Hydraulic vacuum tubes D) Drilling ships Answer: ...
Horizontal and Vertical Crustal Deformation profiles of a simple
... Email: [email protected], [email protected] Abstract: The process of crustal deformation depends on the type of tectonic plate interactions viz. convergent, divergent and transform. For all the three cases, the topography effect is different. However, higher elevations and huge c ...
... Email: [email protected], [email protected] Abstract: The process of crustal deformation depends on the type of tectonic plate interactions viz. convergent, divergent and transform. For all the three cases, the topography effect is different. However, higher elevations and huge c ...
Evolution of the Earth as an andesite planet: water
... obtained and compared to the observed layered structure. The amount of H2O in magma governs the amount of hydrous phases in a solidified rock and may be a critical control on its physical properties. It was possible to estimate the H2O content in magmas by mixing the basalt magma, assumed to contain ...
... obtained and compared to the observed layered structure. The amount of H2O in magma governs the amount of hydrous phases in a solidified rock and may be a critical control on its physical properties. It was possible to estimate the H2O content in magmas by mixing the basalt magma, assumed to contain ...
A mantle convection perspective on global tectonics
... Čadek and Ricard, 1992; O’Connell et al., 1991; Olson and Bercovici, 1991). This holds substantial information about the mutual dynamics of the convecting mantle and the lithosphere (see Bercovici et al., 2015, for a review). Indeed, the poloidal component corresponds to the vertical and horizontal ...
... Čadek and Ricard, 1992; O’Connell et al., 1991; Olson and Bercovici, 1991). This holds substantial information about the mutual dynamics of the convecting mantle and the lithosphere (see Bercovici et al., 2015, for a review). Indeed, the poloidal component corresponds to the vertical and horizontal ...
Geology - Central Washington University Geological Sciences
... a result of excess transitory magmatism immediately after continental breakup (White et al., 1987). In contrast, oceanic crust adjacent to transform margins is formed at mature spreading centers in steady-state thermal conditions. This process typically results in either normal-thickness crust or, i ...
... a result of excess transitory magmatism immediately after continental breakup (White et al., 1987). In contrast, oceanic crust adjacent to transform margins is formed at mature spreading centers in steady-state thermal conditions. This process typically results in either normal-thickness crust or, i ...
Dynamic lithosphere within the Great Basin
... the margins accommodating most of the strain within the region. Late-Cretaceous and Cenozoic volcanism within the Great Basin can be divided into two phases. The first occurred prior to 18 Ma and is part of two concurrent time-transgressive sweeps of volcanism, referred to as the Ignimbrite Flare Up ...
... the margins accommodating most of the strain within the region. Late-Cretaceous and Cenozoic volcanism within the Great Basin can be divided into two phases. The first occurred prior to 18 Ma and is part of two concurrent time-transgressive sweeps of volcanism, referred to as the Ignimbrite Flare Up ...
How Plate-forming Processes Explain Structure and Shortening in
... section was constructed and restored using balancing techniques constrained by stratigraphic data from wells, seismic reflection profiles and field geological mapping. Crustal shortening, R, is calculated as a ratio, in percent, of the amount of horizontal shortening accumulated since the initiation ...
... section was constructed and restored using balancing techniques constrained by stratigraphic data from wells, seismic reflection profiles and field geological mapping. Crustal shortening, R, is calculated as a ratio, in percent, of the amount of horizontal shortening accumulated since the initiation ...
Author`s personal copy - School of Arts and Sciences
... that suggests lithospheric thinning occurred 10–6 Ma. Paleoaltimetry data suggest a rapid ∼ 2.5 km elevation gain 10 to 6 Ma, but are equally consistent within error with a linear rise since ≥ 25 Ma. Widespread fluvial incision (2.5–1 km) occurred along the western flank since ∼ 11–8 Ma and may be ass ...
... that suggests lithospheric thinning occurred 10–6 Ma. Paleoaltimetry data suggest a rapid ∼ 2.5 km elevation gain 10 to 6 Ma, but are equally consistent within error with a linear rise since ≥ 25 Ma. Widespread fluvial incision (2.5–1 km) occurred along the western flank since ∼ 11–8 Ma and may be ass ...
Chemical composition of Earth`s primitive mantle and its variance: 2
... mantle is expected to have the MORB source composition, although large uncertainties in compositional models for the bulk silicate Earth and continental crust allow for the existence of some small-scale mantle heterogeneity (section 4). The subducted oceanic lithosphere stored within the mantle is a ...
... mantle is expected to have the MORB source composition, although large uncertainties in compositional models for the bulk silicate Earth and continental crust allow for the existence of some small-scale mantle heterogeneity (section 4). The subducted oceanic lithosphere stored within the mantle is a ...
Chapter 11 - Wide-angle refraction and reflection - U
... However, two innovative strategies using two-ship acquisition have been developed that enable offsets to be recorded to any chosen range while still retaining the advantages of a densely sampled multichannel streamer. The first of these is called an ‘expanding spread configuration’ (Fig. 11.1D; Buhl ...
... However, two innovative strategies using two-ship acquisition have been developed that enable offsets to be recorded to any chosen range while still retaining the advantages of a densely sampled multichannel streamer. The first of these is called an ‘expanding spread configuration’ (Fig. 11.1D; Buhl ...
How do subduction processes contribute to forearc - HAL-Insu
... Coasts North of 40°S have been uplifting during the Pleistocene. These authors note that this Quaternary renewal of coastal uplift contrasts with the stability and/or subsidence that prevailed before the Middle Pleistocene (Fuenzalida et al., 1965 ; Paskoff, 1978 ; Clift & Hartley, 2007; Rodriguez e ...
... Coasts North of 40°S have been uplifting during the Pleistocene. These authors note that this Quaternary renewal of coastal uplift contrasts with the stability and/or subsidence that prevailed before the Middle Pleistocene (Fuenzalida et al., 1965 ; Paskoff, 1978 ; Clift & Hartley, 2007; Rodriguez e ...
Faulting and hydration of the Juan de Fuca plate system
... largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited ...
... largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited ...
How do subduction processes contribute to forearc Andean uplift
... We also neglect thermal effects affecting the subducting plate. The age-depending thermal state of the oceanic plate is taken into account changing the thickness of the mantle lithosphere, which both modifies the strength and the buoyancy of the plate. Younger oceanic plates are hotter, thinner and a ...
... We also neglect thermal effects affecting the subducting plate. The age-depending thermal state of the oceanic plate is taken into account changing the thickness of the mantle lithosphere, which both modifies the strength and the buoyancy of the plate. Younger oceanic plates are hotter, thinner and a ...
G. Heinson, Electromagnetic studies of the lithosphere and
... Electromagnetic (EM) observations provide complementary information on lithosphereasthenosphere structure in terms of electrical conductivity. Laboratory studies of mantle minerals show that EM observations are very sensitive to the presence of melt or volatiles. A high conductivity zone (HCZ) in th ...
... Electromagnetic (EM) observations provide complementary information on lithosphereasthenosphere structure in terms of electrical conductivity. Laboratory studies of mantle minerals show that EM observations are very sensitive to the presence of melt or volatiles. A high conductivity zone (HCZ) in th ...
Subduction of oceanic lithosphere
... peridotite to form amphibole again (E). This descends until the amphibole breaks down again (F). Amphibole peridotite forms (G), descends, and breaks down again (H). The dark shaded area is mantle that can melt if sufficient water is provided. Above point H the mantle is sufficiently hot that water ...
... peridotite to form amphibole again (E). This descends until the amphibole breaks down again (F). Amphibole peridotite forms (G), descends, and breaks down again (H). The dark shaded area is mantle that can melt if sufficient water is provided. Above point H the mantle is sufficiently hot that water ...
PALAEOMAGNETISM, PLATE MOTION AND POLAR WANDER
... number of virtual magnetic poles sufficient to average out secular variation are known as palaeomagnetic poles, which are assumed to correspond to past geographic (rotation) poles. When palaeomagnetic poles for a particular continent are plotted on a map, they tend to ‘wander’ away from the spin axi ...
... number of virtual magnetic poles sufficient to average out secular variation are known as palaeomagnetic poles, which are assumed to correspond to past geographic (rotation) poles. When palaeomagnetic poles for a particular continent are plotted on a map, they tend to ‘wander’ away from the spin axi ...
pdf version - Berkeley Seismological Lab
... ential movement. These are zones of late Cenozoic to the present tectonic deformation which likely have a series of fault zones. Almost all earthquakes of magnitude >8 and 80–90% of earthquakes of M > 7 occur along these boundaries (Zhang et al. 2003). Groundwater levels rose in the Chuandian block, ...
... ential movement. These are zones of late Cenozoic to the present tectonic deformation which likely have a series of fault zones. Almost all earthquakes of magnitude >8 and 80–90% of earthquakes of M > 7 occur along these boundaries (Zhang et al. 2003). Groundwater levels rose in the Chuandian block, ...
Configuration of subducting Philippine Sea plate and crustal
... region. The crustal velocity structure for the central part of Japan and configuration of the subducting Philippine Sea plate were revealed. A large lateral variation of the thickness of the sedimentary layer was observed, and the P-wave velocity values below the sedimentary layer obtained were 5.3– ...
... region. The crustal velocity structure for the central part of Japan and configuration of the subducting Philippine Sea plate were revealed. A large lateral variation of the thickness of the sedimentary layer was observed, and the P-wave velocity values below the sedimentary layer obtained were 5.3– ...
conductivity structure of crust and upper mantle beneath the
... flow and velocity structure show that in southern Tibet the crust is hot with low velocity and the mantle is cold with high velocity, and both are just contrary in northern Tibet[7] . Therefore it has been suggested that southern Tibet has hot crust and cold mantle, and northern Tibet has cold crust ...
... flow and velocity structure show that in southern Tibet the crust is hot with low velocity and the mantle is cold with high velocity, and both are just contrary in northern Tibet[7] . Therefore it has been suggested that southern Tibet has hot crust and cold mantle, and northern Tibet has cold crust ...
Plate Tectonics: A Paradigm Under Threat
... but do not provide evidence for plate motions of the kind predicted by plate tectonics unless the relative motions predicted among all plates are observed. However, many of the results have shown no definite pattern and have been confusing and contradictory, giving rise to a variety of ad hoc hypoth ...
... but do not provide evidence for plate motions of the kind predicted by plate tectonics unless the relative motions predicted among all plates are observed. However, many of the results have shown no definite pattern and have been confusing and contradictory, giving rise to a variety of ad hoc hypoth ...
Behaviour of high field strength elements in subduction zones
... Amongst other hypotheses, the observed variations have been attributed to subduction processes involving rutile or amphibole [35 – 37]. Using the HFSE data for the Kamchatka/Aleutian rocks, we attempt (1) to assess differences in HFSE mobility during slab melting and dehydration and (2) to identify ...
... Amongst other hypotheses, the observed variations have been attributed to subduction processes involving rutile or amphibole [35 – 37]. Using the HFSE data for the Kamchatka/Aleutian rocks, we attempt (1) to assess differences in HFSE mobility during slab melting and dehydration and (2) to identify ...
Post-glacial rebound
Post-glacial rebound (sometimes called continental rebound) is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period, through a process known as isostatic depression. Post-glacial rebound and isostatic depression are different parts of a process known as either glacial isostasy, glacial isostatic adjustment, or glacioisostasy. Glacioisostasy is the solid Earth deformation associated with changes in ice mass distribution. The most obvious and direct affects of post-glacial rebound are readily apparent in northern Europe (especially Scotland, Estonia, Latvia, Fennoscandia, and northern Denmark), Siberia, Canada, the Great Lakes of Canada and the United States, the coastal region of the US state of Maine, parts of Patagonia, and Antarctica. However, through processes known as ocean siphoning and continental levering, the effects of post-glacial rebound on sea-level are felt globally far from the locations of current and former ice sheets.