Why subduction zones are curved - Harvard John A. Paulson School
... [1] We give an explanation for the polarity, localization, shape, size, and initiation of subduction zones on Earth. By considering a soft, thin, curved lithospheric cap with either elastic or viscous rheology supported by a thick, nearly incompressible mantle, we find two different characteristic s ...
... [1] We give an explanation for the polarity, localization, shape, size, and initiation of subduction zones on Earth. By considering a soft, thin, curved lithospheric cap with either elastic or viscous rheology supported by a thick, nearly incompressible mantle, we find two different characteristic s ...
Ocean Basin Evolution and Global
... Conventional models of global plate motions once took the form of reconstructed map snapshots through time, often without an accompanying digital rotation model describing the motions of the plates and without present-day digital plate polygons that clarify which features on Earth’s surface moved ac ...
... Conventional models of global plate motions once took the form of reconstructed map snapshots through time, often without an accompanying digital rotation model describing the motions of the plates and without present-day digital plate polygons that clarify which features on Earth’s surface moved ac ...
EASTERN RIFT STRUCTURAL GEOLOGY – TECTONICS
... from which the three branches radiate is called a "triple junction", in this case the Afar region of Ethiopia, where two branches are occupied by the Red Sea and Gulf of Aden, and the third rift branch runs to the south through Ethiopia. In Kenya, the East African/Gregory Rift depicts "continental r ...
... from which the three branches radiate is called a "triple junction", in this case the Afar region of Ethiopia, where two branches are occupied by the Red Sea and Gulf of Aden, and the third rift branch runs to the south through Ethiopia. In Kenya, the East African/Gregory Rift depicts "continental r ...
Temporal variation in relative zircon abundance throughout Earth
... record. Given that basalts display the greatest delay in zircon saturation and are substantially over-represented in the volcanic record (Keller et al., 2015), the effect of eruptive quenching on zircon saturation will be most noticeable in the mafic record. Phanerozoic basalts typically erupt with ...
... record. Given that basalts display the greatest delay in zircon saturation and are substantially over-represented in the volcanic record (Keller et al., 2015), the effect of eruptive quenching on zircon saturation will be most noticeable in the mafic record. Phanerozoic basalts typically erupt with ...
res terrae - Oulun yliopisto
... The reader is referred to them for closer information of the diverse volcanic and sedimentary units and unconformities within this unique Mesoproterozoic rock record in the SW part of the Fennoscandian Shield. All the rocks of the Oftefjell group are metamorphic, for they were metamorphosed under th ...
... The reader is referred to them for closer information of the diverse volcanic and sedimentary units and unconformities within this unique Mesoproterozoic rock record in the SW part of the Fennoscandian Shield. All the rocks of the Oftefjell group are metamorphic, for they were metamorphosed under th ...
Adakitic magmas: modern analogues of Archaean granitoids
... 1995; Blais et al., 1997.. However, if plate tectoniclike processes operated, secular compositional changes in magmatism and tectonic regimes indicate that in detail, the processes were different from modern ones. Most of the differences result from greater Archaean heat production, inducing higher ...
... 1995; Blais et al., 1997.. However, if plate tectoniclike processes operated, secular compositional changes in magmatism and tectonic regimes indicate that in detail, the processes were different from modern ones. Most of the differences result from greater Archaean heat production, inducing higher ...
Dynamical geochemistry of the mantle
... buoyancy would generate surface topography comparable to the topography of the mid-ocean ridge system. No such topography exists. The only topography attributable to buoyant upwellings is the hotspot swells, whose amplitude implies quite directly that the upwellings generating them carry less than a ...
... buoyancy would generate surface topography comparable to the topography of the mid-ocean ridge system. No such topography exists. The only topography attributable to buoyant upwellings is the hotspot swells, whose amplitude implies quite directly that the upwellings generating them carry less than a ...
Practice mdtrm
... The true shape of planetary orbits was discovered by ____. a. Newton c. Brahe b. Galileo d. Kepler Earth is closest to the sun at a point called ____. a. perihelion c. apogee b. aphelion d. precession Earth’s axis slowly but continuously points in different directions, a movement known as ____. a. r ...
... The true shape of planetary orbits was discovered by ____. a. Newton c. Brahe b. Galileo d. Kepler Earth is closest to the sun at a point called ____. a. perihelion c. apogee b. aphelion d. precession Earth’s axis slowly but continuously points in different directions, a movement known as ____. a. r ...
Subduction factory 2. Are intermediate
... resistance from the lower mantle; they also noted that some slabs (e.g., those now known to have double seismic zones) have stress states not readily explained by this simple model. Intermediate-depth seismicity has also been explained as the result of unbending of the slab following bending at the ...
... resistance from the lower mantle; they also noted that some slabs (e.g., those now known to have double seismic zones) have stress states not readily explained by this simple model. Intermediate-depth seismicity has also been explained as the result of unbending of the slab following bending at the ...
Relationship between bend‐faulting at trenches and intermediate
... four segments subducting along the study area (Figure 3). Segments 1– 3 were formed at the Cocos-Nazca spreading center, and segment 4 at the East Pacific Rise. Segment 1 spans the Cocos Ridge formed by hot spot magmatism (Figures 1 and 3a). Here the crust is thick [Walther, 2003] and bends little i ...
... four segments subducting along the study area (Figure 3). Segments 1– 3 were formed at the Cocos-Nazca spreading center, and segment 4 at the East Pacific Rise. Segment 1 spans the Cocos Ridge formed by hot spot magmatism (Figures 1 and 3a). Here the crust is thick [Walther, 2003] and bends little i ...
Tremor Troop: Earthquakes – A Teacher`s Package for K
... effects, it is not surprising that people have always looked for ways to explain their origin. We find many nonscientific explanations of earthquakes in the folklore of civilizations around the world. We call ...
... effects, it is not surprising that people have always looked for ways to explain their origin. We find many nonscientific explanations of earthquakes in the folklore of civilizations around the world. We call ...
Subduction of diverging plates and the principles of slab window
... migrating southward beneath the overriding plate. Subducting transform faults which are not parallel to the trench change in length as they subduct (Fig. 4). In this example, the diverging plates are separated by a right-stepping ridge-transform system, and have the same relative plate motions as in ...
... migrating southward beneath the overriding plate. Subducting transform faults which are not parallel to the trench change in length as they subduct (Fig. 4). In this example, the diverging plates are separated by a right-stepping ridge-transform system, and have the same relative plate motions as in ...
A cool model for the Iceland hot spot
... buoyant plume. We suggest an alternative model that attributes the enhanced magmatism in the Iceland region to high local mantle fertility from subducted Iapetus oceanic crust trapped in the Laurasian continental mantle lithosphere within the collision zone assocated with the Caledonian suture. This ...
... buoyant plume. We suggest an alternative model that attributes the enhanced magmatism in the Iceland region to high local mantle fertility from subducted Iapetus oceanic crust trapped in the Laurasian continental mantle lithosphere within the collision zone assocated with the Caledonian suture. This ...
Mechanisms for the formation of ridge-axis topography at
... 1995), and unevenly distributed frictional stresses across the active transform fault (Chen 1989). While each of these mechanisms could qualitatively explain certain aspects of the observed regularities in seafloor topography, none of these models had considered the new gravity and seismic data that ...
... 1995), and unevenly distributed frictional stresses across the active transform fault (Chen 1989). While each of these mechanisms could qualitatively explain certain aspects of the observed regularities in seafloor topography, none of these models had considered the new gravity and seismic data that ...
A trace element perspective on the source of ocean island basalts
... We analyze the first-order observations, basic concepts and explicit/implicit assumptions built into the three major hypotheses for the enriched component(s) in the source of ocean island basalts (OIB) in terms of incompatible trace elements: (1) subducted ocean crust (SOC), (2) subducted continenta ...
... We analyze the first-order observations, basic concepts and explicit/implicit assumptions built into the three major hypotheses for the enriched component(s) in the source of ocean island basalts (OIB) in terms of incompatible trace elements: (1) subducted ocean crust (SOC), (2) subducted continenta ...
KENT C. CONDIE
... The parental theory of plate tectonics, seafloor spreading, states that new lithosphere is formed at ocean ridges and moves away from ridge axes with a motion like that of a conveyor belt as new lithosphere fills in the resulting crack or rift. The mosaic of plates, which range from 50 to over 200 k ...
... The parental theory of plate tectonics, seafloor spreading, states that new lithosphere is formed at ocean ridges and moves away from ridge axes with a motion like that of a conveyor belt as new lithosphere fills in the resulting crack or rift. The mosaic of plates, which range from 50 to over 200 k ...
Post glacial rebounds measure the viscosity of the lithosphere
... North American crust were reported by Bell in 1896 and by Gilbert in 1897. They concluded that warmer weather melted a great amount of ice on the earth’s surface, causing huge mass redistribution. The lithosphere responded to this mass redistribution with deformation, which can be characterized by t ...
... North American crust were reported by Bell in 1896 and by Gilbert in 1897. They concluded that warmer weather melted a great amount of ice on the earth’s surface, causing huge mass redistribution. The lithosphere responded to this mass redistribution with deformation, which can be characterized by t ...
short and long-term folding and faulting of the lithosphere under
... é como se inicia a deformação da litosfera sob compressão horizontal.“Falhamento e dobramento de curto e longo-termo da litosfera sob compressão” é um problema geofísico ainda não resolvido, apesar de vários estudos se terem debruçado sobre ele. Numa litosfera reologicamente estratificada, existe a ...
... é como se inicia a deformação da litosfera sob compressão horizontal.“Falhamento e dobramento de curto e longo-termo da litosfera sob compressão” é um problema geofísico ainda não resolvido, apesar de vários estudos se terem debruçado sobre ele. Numa litosfera reologicamente estratificada, existe a ...
Capitanio et al. - Wiley Online Library
... upper plate [Capitanio, 2014; Duretz et al., 2014; Li et al., 2013]. Other authors have illustrated how the break-off of the subducting lithosphere alters stress coupling along the margins and widens upper plate deformation, where lithospheric faulting and extrusion occur on the side of back-arc str ...
... upper plate [Capitanio, 2014; Duretz et al., 2014; Li et al., 2013]. Other authors have illustrated how the break-off of the subducting lithosphere alters stress coupling along the margins and widens upper plate deformation, where lithospheric faulting and extrusion occur on the side of back-arc str ...
Destruction of the North China Craton
... movement of eastern China in the latter part of the Mesozoic, or the “Platform Reactivation” theory founded by professor Guoda Chen during the period of 1956–1960 [2]. Since the 1980s, several important ideas, such as continental deep subduction [3] (the Qinling-Dabie Mountains on the southern margi ...
... movement of eastern China in the latter part of the Mesozoic, or the “Platform Reactivation” theory founded by professor Guoda Chen during the period of 1956–1960 [2]. Since the 1980s, several important ideas, such as continental deep subduction [3] (the Qinling-Dabie Mountains on the southern margi ...
Geology
Geology (from the Greek γῆ, gē, i.e. ""earth"" and -λoγία, -logia, i.e. ""study of, discourse"") is an earth science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which they change. Geology can also refer generally to the study of the solid features of any celestial body (such as the geology of the Moon or Mars).Geology gives insight into the history of the Earth by providing the primary evidence for plate tectonics, the evolutionary history of life, and past climates. Geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, and for providing insights into past climate change. Geology also plays a role in geotechnical engineering and is a major academic discipline.