Computation of phase equilibria by linear programming
... phase boundaries. Treatment of isentropic and isothermal phase relations involving felsic and mafic silicate melts by this method is illustrated. To demonstrate the tractability of more complex problems involving mass transfer, a model for infiltration driven-decarbonation in subduction zones is eva ...
... phase boundaries. Treatment of isentropic and isothermal phase relations involving felsic and mafic silicate melts by this method is illustrated. To demonstrate the tractability of more complex problems involving mass transfer, a model for infiltration driven-decarbonation in subduction zones is eva ...
Crust and upper mantle discontinuity structure beneath eastern
... refraction profiles and because individual refraction profiles manifest considerable variation even within given tectonic terranes, we did not assume different crustal velocities for different segments of the array. Rather, we modeled all observed crustal receiver functions with three Vp and Vp /Vs ...
... refraction profiles and because individual refraction profiles manifest considerable variation even within given tectonic terranes, we did not assume different crustal velocities for different segments of the array. Rather, we modeled all observed crustal receiver functions with three Vp and Vp /Vs ...
Seismology - Università degli studi di Trieste
... Lehman from Denmark. The boundary between the mantle and outer core is sharp. The outer core is the most homogeneous part of the Earth The change in density across the core-mantle boundary is greater than that at the Earth’s ...
... Lehman from Denmark. The boundary between the mantle and outer core is sharp. The outer core is the most homogeneous part of the Earth The change in density across the core-mantle boundary is greater than that at the Earth’s ...
Serpentinization of the forearc mantle
... the region where hydrous minerals are stable in the forearc mantle. In addition, temperature is important because of the thermal dependence of the physical properties of the forearc mantle rocks. Interpretation of geophysical data in terms of forearc mantle hydration requires separation of the e¡ect ...
... the region where hydrous minerals are stable in the forearc mantle. In addition, temperature is important because of the thermal dependence of the physical properties of the forearc mantle rocks. Interpretation of geophysical data in terms of forearc mantle hydration requires separation of the e¡ect ...
Future accreted terranes: a compilation of island arcs, oceanic
... to accreted terranes using new geophysical and geological studies from the last couple of decades. We group island arcs, oceanic LIPs, submarine ridges, seamounts, hot spots, submarine continental fragments, and microcontinents all as future allochthonous terranes (FATs). Although accreted terranes ...
... to accreted terranes using new geophysical and geological studies from the last couple of decades. We group island arcs, oceanic LIPs, submarine ridges, seamounts, hot spots, submarine continental fragments, and microcontinents all as future allochthonous terranes (FATs). Although accreted terranes ...
Thermal state of the lithosphere in the Danube Basin and its relation
... surface is also observed in the opposite direction namely on the contact zone of the Inner Carpathian units with the Transdanubian Central Range block. In both these neighbouring geological units the terrestrial heat flow densities are smaller than the value of the 50 mW/m 2 . This is evidently visib ...
... surface is also observed in the opposite direction namely on the contact zone of the Inner Carpathian units with the Transdanubian Central Range block. In both these neighbouring geological units the terrestrial heat flow densities are smaller than the value of the 50 mW/m 2 . This is evidently visib ...
Atlantic Ridge − spreading Mid − Evidence for accumulated melt
... At its northern end, the Reykjanes Ridge is profoundly affected by the proximity of the Iceland hot spot, which results in anomalously shallow water depths, the absence of a median valley and a crustal composition dominated by plume geochemistry. The hot spot influence decreases with increasing dist ...
... At its northern end, the Reykjanes Ridge is profoundly affected by the proximity of the Iceland hot spot, which results in anomalously shallow water depths, the absence of a median valley and a crustal composition dominated by plume geochemistry. The hot spot influence decreases with increasing dist ...
AZU_TD_BOX206_E9791_
... The Nazca plate includes significant lengths of all three kinds of plate boundary: ...
... The Nazca plate includes significant lengths of all three kinds of plate boundary: ...
Numerical and laboratory studies of mantle convection: Philosophy
... dense material comprises 30% of mantle volume (Figure 1 left columns), a continuous undulating layer is formed, with hot upwellings rising from ridges of the dense layer. When the dense material comprises only 10% of mantle volume (Figure 1 right columns), it is swept into ridges separated by expose ...
... dense material comprises 30% of mantle volume (Figure 1 left columns), a continuous undulating layer is formed, with hot upwellings rising from ridges of the dense layer. When the dense material comprises only 10% of mantle volume (Figure 1 right columns), it is swept into ridges separated by expose ...
... The existence of the SPA basin was suspected as early as 1962, but global photography by the Lunar Orbiter Program in the mid-1960s confirmed its existence. The first complete map was published in 1978 by D. Stuart-Alexander of the U. S. Geological Survey. The basin was not the center of very many s ...
Lithosphere, Asthenosphere, and Perisphere
... below and protected from contamination (chemical isolation) by the filtering action of this boundary layer. Depleted MORB is most prominent at fast spreading ridges, which induce or localize deep, broad upwellings. Melts from enriched mantle (EM) are most evident at new or slowly rifting regions, in ...
... below and protected from contamination (chemical isolation) by the filtering action of this boundary layer. Depleted MORB is most prominent at fast spreading ridges, which induce or localize deep, broad upwellings. Melts from enriched mantle (EM) are most evident at new or slowly rifting regions, in ...
- BIROn - Birkbeck Institutional Research Online
... (~11–0.2 Ma), generally following the calc-alkaline magmatism in different areas. It comprises monogenetic volcanic fields of maars, diatremes, tuff cones, cinder/ spatter cones and lava flows (Lexa et al., 2010). However, even though it may be important, we are not able to discuss the 11–12 Ma larg ...
... (~11–0.2 Ma), generally following the calc-alkaline magmatism in different areas. It comprises monogenetic volcanic fields of maars, diatremes, tuff cones, cinder/ spatter cones and lava flows (Lexa et al., 2010). However, even though it may be important, we are not able to discuss the 11–12 Ma larg ...
Terrestrial planet evolution in the stagnant
... that crustal material with a temperature above Tcrit = 1273 K is considered to be buoyant melt that migrates within one time step immediately below the planet’s surface, producing a relatively cooler crust and a larger mantle heat flux. This modification is not important for Martian cases, because the ...
... that crustal material with a temperature above Tcrit = 1273 K is considered to be buoyant melt that migrates within one time step immediately below the planet’s surface, producing a relatively cooler crust and a larger mantle heat flux. This modification is not important for Martian cases, because the ...
Slab flattening trigger for isotopic disturbance and magmatic flare
... The San Emigdio Schist of Southern California permits examination of partial melting and devolatilization processes along a Late Cretaceous shallow subduction zone. Detrital and recrystallized zircon of the structurally highest portions of the schist bracket the depositional age to between ca. 102 a ...
... The San Emigdio Schist of Southern California permits examination of partial melting and devolatilization processes along a Late Cretaceous shallow subduction zone. Detrital and recrystallized zircon of the structurally highest portions of the schist bracket the depositional age to between ca. 102 a ...
Reconciling the geological history of western Turkey with plate
... mantle. They argue for episodes of Eocene asthenospheric upwelling, either as a result of delamination of the mantle lithosphere, or slab break-off (Aldanmaz et al., 2000; Agostini et al., 2008; Dilek and Altunkaynak, 2009). Here, we aim to reconcile the geological record of western Turkey with the ...
... mantle. They argue for episodes of Eocene asthenospheric upwelling, either as a result of delamination of the mantle lithosphere, or slab break-off (Aldanmaz et al., 2000; Agostini et al., 2008; Dilek and Altunkaynak, 2009). Here, we aim to reconcile the geological record of western Turkey with the ...
Three-dimensional modelling of crustal motions caused by
... and migrated southeastwards with time (e.g. Spadini et al. 1995). A plausible scenario for the opening and evolution of the central Mediterranean has been proposed by Malinverno & Ryan (1986) based on a mechanism of trench retreat or roll-back of the subduction hinge (Elsasser 1971) that causes the ...
... and migrated southeastwards with time (e.g. Spadini et al. 1995). A plausible scenario for the opening and evolution of the central Mediterranean has been proposed by Malinverno & Ryan (1986) based on a mechanism of trench retreat or roll-back of the subduction hinge (Elsasser 1971) that causes the ...
Proposal to conduct a Caribbean plate project involving the
... within the regio n, resulting in loss of life and livelihood . For example, inhabitants of two islands in the Lesser Antilles , Guadeloupe and St. Vincent, have had to be evacuated from threatening explosive eruptions of neighboring volcanoes. Finally, the CaribbeM. possesses several distinctive geo ...
... within the regio n, resulting in loss of life and livelihood . For example, inhabitants of two islands in the Lesser Antilles , Guadeloupe and St. Vincent, have had to be evacuated from threatening explosive eruptions of neighboring volcanoes. Finally, the CaribbeM. possesses several distinctive geo ...
Polarity Reversal of Active Plate Boundary and Elevated Oceanic
... area (Fig. 2). The TSN is operated by the Central Weather Bureau (CWB) and consists of 78 three-component shortperiod stations. All the arrival times and earthquake-location files from 1991 to 2002 reported by the CWB have been collected and analyzed in this study. The events selected for velocity d ...
... area (Fig. 2). The TSN is operated by the Central Weather Bureau (CWB) and consists of 78 three-component shortperiod stations. All the arrival times and earthquake-location files from 1991 to 2002 reported by the CWB have been collected and analyzed in this study. The events selected for velocity d ...
A dynamic model of hot fingers in the mantle wedge in
... fluids, would produce arc magmas showing the isotopic variations of Pb, Sr and Nd observed in Quaternary volcanoes. On the other hand, Tamaki et al. (1992) noted that major opening associated with vigorous basin volcanism of Japan Sea occurred about 28 to 18Ma. Interestingly, basaltic rocks from the ...
... fluids, would produce arc magmas showing the isotopic variations of Pb, Sr and Nd observed in Quaternary volcanoes. On the other hand, Tamaki et al. (1992) noted that major opening associated with vigorous basin volcanism of Japan Sea occurred about 28 to 18Ma. Interestingly, basaltic rocks from the ...
Glossary a - Teacher Friendly Guides
... the upper surface of all oceanic plates, and is the principal rock of ocean/seafloor ridges, oceanic islands, and high-volume continental eruptions. Basalt is fine-grained and mostly dark-colored, although it often weathers to reds and browns because of its high iron content. Basaltic magmas are pro ...
... the upper surface of all oceanic plates, and is the principal rock of ocean/seafloor ridges, oceanic islands, and high-volume continental eruptions. Basalt is fine-grained and mostly dark-colored, although it often weathers to reds and browns because of its high iron content. Basaltic magmas are pro ...
Linking rift propagation barriers to excess magmatism at volcanic
... In agreement with observations from the North and South Atlantic, and as imposed by the model’s boundary conditions, break-up in the model occurs via rift propagation (Figs. 2B and 2C). In the same manner, the area affected by decompression melting (between 65 km and 15 km depth beneath the rift cen ...
... In agreement with observations from the North and South Atlantic, and as imposed by the model’s boundary conditions, break-up in the model occurs via rift propagation (Figs. 2B and 2C). In the same manner, the area affected by decompression melting (between 65 km and 15 km depth beneath the rift cen ...
Plate tectonics
Plate tectonics (from the Late Latin tectonicus, from the Greek: τεκτονικός ""pertaining to building"") is a scientific theory that describes the large-scale motion of Earth's lithosphere. This theoretical model builds on the concept of continental drift which was developed during the first few decades of the 20th century. The geoscientific community accepted the theory after the concepts of seafloor spreading were later developed in the late 1950s and early 1960s.The lithosphere, which is the rigid outermost shell of a planet (on Earth, the crust and upper mantle), is broken up into tectonic plates. On Earth, there are seven or eight major plates (depending on how they are defined) and many minor plates. Where plates meet, their relative motion determines the type of boundary; convergent, divergent, or transform. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The lateral relative movement of the plates typically varies from zero to 100 mm annually.Tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle; the material lost is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading. In this way, the total surface of the globe remains the same. This prediction of plate tectonics is also referred to as the conveyor belt principle. Earlier theories (that still have some supporters) propose gradual shrinking (contraction) or gradual expansion of the globe.Tectonic plates are able to move because the Earth's lithosphere has greater strength than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the spreading ridge (due to variations in topography and density of the crust, which result in differences in gravitational forces) and drag, with downward suction, at the subduction zones. Another explanation lies in the different forces generated by the rotation of the globe and the tidal forces of the Sun and Moon. The relative importance of each of these factors and their relationship to each other is unclear, and still the subject of much debate.