Magma Generation (SERC)
... Tholeiites favored by shallower melting 25% melting at <30 km tholeiite 25% melting at 60 km olivine basalt Tholeiites favored by greater % partial melting (F) 20 % melting at 60 km alkaline basalt ...
... Tholeiites favored by shallower melting 25% melting at <30 km tholeiite 25% melting at 60 km olivine basalt Tholeiites favored by greater % partial melting (F) 20 % melting at 60 km alkaline basalt ...
Anisotropy and deformation beneath the Eastern Alps
... (primary wave) and S wave (secondary) respectively. In the 3-components seismometers, three orthogonal components (north-south, east-west, and vertical) record the displacements in three directions. The records of horizontal components are often rotated to source-receiver direction, called the radia ...
... (primary wave) and S wave (secondary) respectively. In the 3-components seismometers, three orthogonal components (north-south, east-west, and vertical) record the displacements in three directions. The records of horizontal components are often rotated to source-receiver direction, called the radia ...
Terrestrial Planet Evolution in the Stagnant
... to quantify the relationship between initial conditions and modeling results. Principal component analysis is used to simplify the interpretation of a large number of simulation results. Simple scaling analyses are also conducted to derive a theoretical basis for major modeling results. Moreover, th ...
... to quantify the relationship between initial conditions and modeling results. Principal component analysis is used to simplify the interpretation of a large number of simulation results. Simple scaling analyses are also conducted to derive a theoretical basis for major modeling results. Moreover, th ...
Intracratonic asthenosphere upwelling and lithosphere rejuvenation
... by metasomatic processes. In samples containing 10–12% modal cpx this enrichment is restricted to the lightest (more incompatible) REE, i.e. La and Ce, thus displaying spoonshape patterns with LaN/YbN up to 3, CeN/YbN up to 1.6, and NdN/YbN up 1.2. Samples characterized by lower modal cpx (8–9%), su ...
... by metasomatic processes. In samples containing 10–12% modal cpx this enrichment is restricted to the lightest (more incompatible) REE, i.e. La and Ce, thus displaying spoonshape patterns with LaN/YbN up to 3, CeN/YbN up to 1.6, and NdN/YbN up 1.2. Samples characterized by lower modal cpx (8–9%), su ...
Teacher Guide - Windows to the Universe
... A general understanding of plate tectonics is required for this lesson. Many excellent learning resources are available online covering lines of evidence to support the theory of plate tectonics. Many of these resources take a global view of plate tectonics; this lesson explores how high-precision G ...
... A general understanding of plate tectonics is required for this lesson. Many excellent learning resources are available online covering lines of evidence to support the theory of plate tectonics. Many of these resources take a global view of plate tectonics; this lesson explores how high-precision G ...
Precambrian Research Geochemical and numerical constraints
... many challenges, and constructing uniform views from different disciplines on Archean plate tectonic models requires overcoming several geological, geochemical, and geophysical hurdles. First of all, time has taken its toll: Archean sites are now relatively sparse, and data are fragmented. This make ...
... many challenges, and constructing uniform views from different disciplines on Archean plate tectonic models requires overcoming several geological, geochemical, and geophysical hurdles. First of all, time has taken its toll: Archean sites are now relatively sparse, and data are fragmented. This make ...
Terrestrial planets fractionated synchronously
... all or most of geologic time. Venus is assigned a much more vigorously circulating mantle, but beneath a thin unbroken lithosphere that was transformed by plume-generated vertical tectonism a half-billion years ago. Venusian topography then generated has since been precisely maintained dynamically b ...
... all or most of geologic time. Venus is assigned a much more vigorously circulating mantle, but beneath a thin unbroken lithosphere that was transformed by plume-generated vertical tectonism a half-billion years ago. Venusian topography then generated has since been precisely maintained dynamically b ...
7-1 Continental Drift Hypothesis test and answers
... forming in east Africa. PTS: 1 DIF: Bloom's Level 4 | DOK 2-MOD REF: To review this topic refer to Plate Tectonics: Lesson 1 OBJ: 7-1 2. ANS: Evidence that Wegener used to support his theory included the way that the continents seemed to fit together like puzzle pieces, the location of similar fossi ...
... forming in east Africa. PTS: 1 DIF: Bloom's Level 4 | DOK 2-MOD REF: To review this topic refer to Plate Tectonics: Lesson 1 OBJ: 7-1 2. ANS: Evidence that Wegener used to support his theory included the way that the continents seemed to fit together like puzzle pieces, the location of similar fossi ...
Isostasy, flexure, and dynamic topography
... topography was shown to be always much higher than the observed topography. Zoback and Mooney (2003) explained that the negative buoyancy of the ML lowers the observed topography by 1.73 km on average (Fig. 1). Moreover, they computed the thickness of the ML for each point in their dataset and showe ...
... topography was shown to be always much higher than the observed topography. Zoback and Mooney (2003) explained that the negative buoyancy of the ML lowers the observed topography by 1.73 km on average (Fig. 1). Moreover, they computed the thickness of the ML for each point in their dataset and showe ...
Generalized Geologic Setting of the Pacific Northwest
... Figure 5. The circles on the cross-section diagram show positions of earthquakes relative to the Juan de Fuca and North American plates. Types of earthquakes in the Pacific Northwest: Crustal earthquakes — Shallow earthquakes (less than 15 miles deep) occur on faults within the North American contin ...
... Figure 5. The circles on the cross-section diagram show positions of earthquakes relative to the Juan de Fuca and North American plates. Types of earthquakes in the Pacific Northwest: Crustal earthquakes — Shallow earthquakes (less than 15 miles deep) occur on faults within the North American contin ...
SEISMIC AND ASEISMIC SLIP ALONG SUBDUCTION ZONES AND
... motion seems to take place aseismically. It is proposed that such coupling and decoupling of plates may play an essential role in the evolution of island arcs and marginal seas. Summary of Characteristics of Great Earthquakes along the Circum Pacific Belt Figure 1 shows the rupture zones and the mec ...
... motion seems to take place aseismically. It is proposed that such coupling and decoupling of plates may play an essential role in the evolution of island arcs and marginal seas. Summary of Characteristics of Great Earthquakes along the Circum Pacific Belt Figure 1 shows the rupture zones and the mec ...
Crustal and upper mantle structure of southernmost South America
... The P velocity for each layer is derived from the relationship a = gb, where g is the ratio of P velocity to S velocity. We used the preliminary reference Earth model (PREM) values to determine the a/b ratio, and the density of each layer was calculated from the formula r = r0 + 0.32(a-a0), where r0 ...
... The P velocity for each layer is derived from the relationship a = gb, where g is the ratio of P velocity to S velocity. We used the preliminary reference Earth model (PREM) values to determine the a/b ratio, and the density of each layer was calculated from the formula r = r0 + 0.32(a-a0), where r0 ...
Canada`s craton: A bottoms-up view
... recognized within the cratons of continents today (Bleeker, 2003). The largest mass of lithosphere beneath these cratons underlies the Moho in the mantle. Thus, the long-term strength and stability of a craton must be engendered in the properties of its mantle lithosphere, which may ultimately be ti ...
... recognized within the cratons of continents today (Bleeker, 2003). The largest mass of lithosphere beneath these cratons underlies the Moho in the mantle. Thus, the long-term strength and stability of a craton must be engendered in the properties of its mantle lithosphere, which may ultimately be ti ...
Deformation of the Continental Crust
... here for the ancient history of Earth. • orogeny: sum of the tectonic forces (i.e., deformation, magmatism, metamorphism, erosion) that produce mountain belts ...
... here for the ancient history of Earth. • orogeny: sum of the tectonic forces (i.e., deformation, magmatism, metamorphism, erosion) that produce mountain belts ...
High-resolution estimates of lithospheric thickness from Missouri to
... lack of heat £ow data along and south of the relevant (western) part of the MOMA pro¢le [17]. Compositional thickness of the lithosphere has not been estimated along the MOMA pro¢le because of a lack of rock samples and electrical conductivity measurements. However, Permian kimberlite activity has b ...
... lack of heat £ow data along and south of the relevant (western) part of the MOMA pro¢le [17]. Compositional thickness of the lithosphere has not been estimated along the MOMA pro¢le because of a lack of rock samples and electrical conductivity measurements. However, Permian kimberlite activity has b ...
Chapter 8 Let`s take it from the top: the crust and upper mantle
... (3) Tayor and McLenna n (1985). ...
... (3) Tayor and McLenna n (1985). ...
Chapter_15_Lecture
... • Polar wandering (evidence that continents moved) • Earth's magnetic field reversals • Recorded in rocks as they form at oceanic ridges ...
... • Polar wandering (evidence that continents moved) • Earth's magnetic field reversals • Recorded in rocks as they form at oceanic ridges ...
Southeast Asia`s changing palaeogeography
... grew incrementally by the addition of continental fragments, mainly rifted from Australia, and added to the margins of Sundaland as a result of subduction. Sundaland was an almost permanent land area from the beginning of the Mesozoic. The addition of the continental fragments of Southwest Borneo an ...
... grew incrementally by the addition of continental fragments, mainly rifted from Australia, and added to the margins of Sundaland as a result of subduction. Sundaland was an almost permanent land area from the beginning of the Mesozoic. The addition of the continental fragments of Southwest Borneo an ...
Regional phases in continental and oceanic environments
... The mantle source injects more energy into the mantle arrivals Pn, Sn than the shallower source. Also, the mantle phases arising from the surface reflections are more distinct, as for example for Sn on the continental side at a range of 300 km and reduced time of about 42 s. The group of mantle refl ...
... The mantle source injects more energy into the mantle arrivals Pn, Sn than the shallower source. Also, the mantle phases arising from the surface reflections are more distinct, as for example for Sn on the continental side at a range of 300 km and reduced time of about 42 s. The group of mantle refl ...
Plate Tectonics: Note 2 T. Seno (Earthquake Res Inst, Univ of Tokyo
... This strike-slip fault is elongated along the Coast Range, western US, actually consists of ~three subparallel faults. This correctly is called the San Andreas fault system. It is peculiar that it exists within the N. American continent, but Atwater (1970) explained its origin as follows. There was ...
... This strike-slip fault is elongated along the Coast Range, western US, actually consists of ~three subparallel faults. This correctly is called the San Andreas fault system. It is peculiar that it exists within the N. American continent, but Atwater (1970) explained its origin as follows. There was ...
Chapter 8 Plate Tectonics
... mid-ocean ridges A divergent boundary is the line between two plates where they are moving apart. This type of boundary is found over the rising plume of a mantle convection cell. The convection cell causes the two plates to move away from each other. As they move, melted rock fills the space create ...
... mid-ocean ridges A divergent boundary is the line between two plates where they are moving apart. This type of boundary is found over the rising plume of a mantle convection cell. The convection cell causes the two plates to move away from each other. As they move, melted rock fills the space create ...
Lecture 19: Mantle Plumes - Earth and Atmospheric Sciences
... peridotite, with a subordinate fraction of oceanic crust. However, because the oceanic crust has much higher incompatible element concentrations than peridotite, it provides most of the isotopic and incompatible element “flavor” of plumes. Trace elements provide some evidence that some plumes contai ...
... peridotite, with a subordinate fraction of oceanic crust. However, because the oceanic crust has much higher incompatible element concentrations than peridotite, it provides most of the isotopic and incompatible element “flavor” of plumes. Trace elements provide some evidence that some plumes contai ...
Imaging the Gutenberg Seismic Discontinuity beneath the Oceanic
... 660 km discontinuities are from phase changes in the mineral olivine. Other discontinuities like the one found at the mantle-outer core boundary is from the transition of rock to liquid metal. However, there are several discontinuities other than those listed above that do not necessarily have a cle ...
... 660 km discontinuities are from phase changes in the mineral olivine. Other discontinuities like the one found at the mantle-outer core boundary is from the transition of rock to liquid metal. However, there are several discontinuities other than those listed above that do not necessarily have a cle ...
Pattern Recognition in Physics Regional pattern of the earth`s crust
... good correspondence between gravity field distribution and the existing tectonic zonation (Fig. 1) is not observed, the derivative calculations have the power to reveal features that cannot be detected by direct observations. The map of THG, shown in Fig. 3, indicates the axes of steep gravity trans ...
... good correspondence between gravity field distribution and the existing tectonic zonation (Fig. 1) is not observed, the derivative calculations have the power to reveal features that cannot be detected by direct observations. The map of THG, shown in Fig. 3, indicates the axes of steep gravity trans ...
GEOL_10_mid_term_I_k..
... (12) 2 pts. Which of the following best describes the fundamental concept of superposition? A) Any sedimentary deposit accumulates on older rock or sediment layers. B) Older strata generally are deposited on younger strata without intervening, intermediate age strata. C) Strata with fossils are gene ...
... (12) 2 pts. Which of the following best describes the fundamental concept of superposition? A) Any sedimentary deposit accumulates on older rock or sediment layers. B) Older strata generally are deposited on younger strata without intervening, intermediate age strata. C) Strata with fossils are gene ...
Post-glacial rebound
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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.