Meteorite Jesenice: Mineral and chemical composition of
... (McSween, 1999; Triglav, 2000), which are subspherical or sometimes ellipsoidal structures with diameters of 0.1 mm up to 4 mm (Kohout, 2009). They may be porphyritic, granular or glassy in texture (MacDonald et al., 2003). Chondrules are composed of different minerals, although olivine and pyroxene ...
... (McSween, 1999; Triglav, 2000), which are subspherical or sometimes ellipsoidal structures with diameters of 0.1 mm up to 4 mm (Kohout, 2009). They may be porphyritic, granular or glassy in texture (MacDonald et al., 2003). Chondrules are composed of different minerals, although olivine and pyroxene ...
22 Hotspots and Mantle Plumes
... head can develop only if it traverses a large distance. Using this relationship, we can estimate that plumes must rise thousands of kilometers, probably from the core-mantle boundary to the surface—a distance of 2700 km. If this is true, much of the heat lost from the molten metallic core is carried ...
... head can develop only if it traverses a large distance. Using this relationship, we can estimate that plumes must rise thousands of kilometers, probably from the core-mantle boundary to the surface—a distance of 2700 km. If this is true, much of the heat lost from the molten metallic core is carried ...
Where and why do large shallow slab earthquakes occur?
... event numbers (Table 1); for the three historical events near Japan (Events 2, 4 and 5), only their epicenters are plotted because reliable mechanisms are not available. Sources of the mechanism solutions are described in the caption of Table 1. The mechanism solutions in Figure 1 show both normal a ...
... event numbers (Table 1); for the three historical events near Japan (Events 2, 4 and 5), only their epicenters are plotted because reliable mechanisms are not available. Sources of the mechanism solutions are described in the caption of Table 1. The mechanism solutions in Figure 1 show both normal a ...
Peculiarities of roughness and thickness of oceanic crust in the
... oceanic crust made rugged by faults. Presumably, a change between volcanic activity and normal faulting of crustal blocks due to tectonic strain during drifting supports the roughness of basement surface (Louden et al. 1996). These characteristics are supposed to be strongly developed along the supe ...
... oceanic crust made rugged by faults. Presumably, a change between volcanic activity and normal faulting of crustal blocks due to tectonic strain during drifting supports the roughness of basement surface (Louden et al. 1996). These characteristics are supposed to be strongly developed along the supe ...
Evolution of the continental crust
... in that it has strongly depleted incompatible-element abundances (for example, U, Th, Pb, La, Zr) and relatively high Ti contents; in other words, it is more refractory and genuinely residual. Relative depletions in certain elements during crustal differentiation reflect the principal mineralogical ...
... in that it has strongly depleted incompatible-element abundances (for example, U, Th, Pb, La, Zr) and relatively high Ti contents; in other words, it is more refractory and genuinely residual. Relative depletions in certain elements during crustal differentiation reflect the principal mineralogical ...
Channel flow and the Himalayan-Tibetan orogen: a critical review
... Although our understanding of the creation and subduction of oceanic lithosphere has advanced rapidly over the past few decades, the processes that control mountain building within the continents remain highly contentious. Recent developments in quantitative modelling of lithospheric deformation, co ...
... Although our understanding of the creation and subduction of oceanic lithosphere has advanced rapidly over the past few decades, the processes that control mountain building within the continents remain highly contentious. Recent developments in quantitative modelling of lithospheric deformation, co ...
Earth,Tests,Ch14
... A) Large, fault blocks of Archean igneous and metamorphic rocks rose as the former Asian and European plates joined to form Eurasia. B) Marine strata in a basin between the former Asian and European plates were squeezed, folded, and uplifted as the two joined to form the Eurasian plate. C) Active, n ...
... A) Large, fault blocks of Archean igneous and metamorphic rocks rose as the former Asian and European plates joined to form Eurasia. B) Marine strata in a basin between the former Asian and European plates were squeezed, folded, and uplifted as the two joined to form the Eurasian plate. C) Active, n ...
Vesta is not an intact protoplanet
... system formation” [1]. However, models of Vesta composed of an iron core, olivine mantle, and HED crust in chondritic proportions cannot match the joint constraints from Dawn [1] of Vesta’s density, core size, and the extremely limited presence of exposed olivine on its surface. Vesta has a mean den ...
... system formation” [1]. However, models of Vesta composed of an iron core, olivine mantle, and HED crust in chondritic proportions cannot match the joint constraints from Dawn [1] of Vesta’s density, core size, and the extremely limited presence of exposed olivine on its surface. Vesta has a mean den ...
Standardized Test Prep Chapter 10
... • Continental drift the hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their ...
... • Continental drift the hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their ...
PDF
... the initial stages of subduction along the Manila (1985) inferred that the ratio of eruption to plu- fore arc and then speculate on why spreading Trench, during the major plate reorganization tonic emplacement for the Aleutian arc is be- stops, marking the end of arc infancy. that led to the formati ...
... the initial stages of subduction along the Manila (1985) inferred that the ratio of eruption to plu- fore arc and then speculate on why spreading Trench, during the major plate reorganization tonic emplacement for the Aleutian arc is be- stops, marking the end of arc infancy. that led to the formati ...
Yin and yang of continental crust creation and destruction by plate
... Mature continental crust is compositionally layered and can be subdivided into upper continental crust (∼20 km thick) of approximately granodioritic composition and lower, mafic crust (∼20 km thick), separated by a Conrad discontinuity that is well to weakly formed (Christensen and Mooney 1995; Rudn ...
... Mature continental crust is compositionally layered and can be subdivided into upper continental crust (∼20 km thick) of approximately granodioritic composition and lower, mafic crust (∼20 km thick), separated by a Conrad discontinuity that is well to weakly formed (Christensen and Mooney 1995; Rudn ...
Deep-Seated Mass Rock Creep Along The Karakoram
... rate this curious rock represents a classical toppling from postglacial time. The kinematics can be understood by studying Plate 2, which shows how the. antithetic faulting took place, namely with the rock left of the steep shear zone moving upward relative to the right side, eventually forming an a ...
... rate this curious rock represents a classical toppling from postglacial time. The kinematics can be understood by studying Plate 2, which shows how the. antithetic faulting took place, namely with the rock left of the steep shear zone moving upward relative to the right side, eventually forming an a ...
Meteorite Impacts as Triggers to Large Igneous Provinces
... This volume of impact melt exceeds that of most LIPs but is slightly less than the total volume of the OJP (>30 × 106 km3). Larger melt volumes will result from hotter mantle potential temperatures (>1500 degrees, e.g. Chazey and Neal 2004). Various other parameters could be changed – projectile dim ...
... This volume of impact melt exceeds that of most LIPs but is slightly less than the total volume of the OJP (>30 × 106 km3). Larger melt volumes will result from hotter mantle potential temperatures (>1500 degrees, e.g. Chazey and Neal 2004). Various other parameters could be changed – projectile dim ...
© Terra Antartica Publication
... relationships are not easily determined. In particular, the following observations should be explained: - The SDRS are detached from the continental margin and are surrounded by probable oceanic crust (shown as ‘Shackleton Basin oceanic crust – shallow’ in Fig. 3). - The SDRS thicken away from the A ...
... relationships are not easily determined. In particular, the following observations should be explained: - The SDRS are detached from the continental margin and are surrounded by probable oceanic crust (shown as ‘Shackleton Basin oceanic crust – shallow’ in Fig. 3). - The SDRS thicken away from the A ...
Gravitational collapse of the continental crust: definition, regimes
... tectonic forces and the strength of both the deformed and surrounding lithosphere) decrease, the gravitational potential anomaly may relax. Depending on the sign of the anomaly, two fundamental regimes of gravitational collapse can be defined. During divergent gravitational collapse, an excess in gr ...
... tectonic forces and the strength of both the deformed and surrounding lithosphere) decrease, the gravitational potential anomaly may relax. Depending on the sign of the anomaly, two fundamental regimes of gravitational collapse can be defined. During divergent gravitational collapse, an excess in gr ...
Gravitational collapse of the continental crust: definition, regimes
... tectonic forces and the strength of both the deformed and surrounding lithosphere) decrease, the gravitational potential anomaly may relax. Depending on the sign of the anomaly, two fundamental regimes of gravitational collapse can be defined. During divergent gravitational collapse, an excess in gr ...
... tectonic forces and the strength of both the deformed and surrounding lithosphere) decrease, the gravitational potential anomaly may relax. Depending on the sign of the anomaly, two fundamental regimes of gravitational collapse can be defined. During divergent gravitational collapse, an excess in gr ...
Lithospheric and upper mantle structure of the northeastern Tibetan
... Figure 2. A map view of station locations (triangles). Ps and Sp converted-wave piercing points are denoted by circle and plus symbols, respectively. Locations of five seismic profiles (dashed lines) are also plotted on this map. The global map on the top right shows locations of the events used for ...
... Figure 2. A map view of station locations (triangles). Ps and Sp converted-wave piercing points are denoted by circle and plus symbols, respectively. Locations of five seismic profiles (dashed lines) are also plotted on this map. The global map on the top right shows locations of the events used for ...
North Atlantic Igneous Province: A Review of
... Igneous Province formation. Alternative models have been suggested, including delamination, meteorite impact, small-scale rift-related convection, and chemical mantle heterogeneities. We review available datasets on uplift, strain localization, age and chemistry of igneous material, and tomography f ...
... Igneous Province formation. Alternative models have been suggested, including delamination, meteorite impact, small-scale rift-related convection, and chemical mantle heterogeneities. We review available datasets on uplift, strain localization, age and chemistry of igneous material, and tomography f ...
Microsoft Word - NewTopographicMapsLab
... and sedimentary material are being shoved downward, toward the east, underneath North America. This down-going material undergoes metamorphism as it becomes exposed to progressively higher pressures and temperatures in the interior of the earth beneath North America. Temperatures at depths of the to ...
... and sedimentary material are being shoved downward, toward the east, underneath North America. This down-going material undergoes metamorphism as it becomes exposed to progressively higher pressures and temperatures in the interior of the earth beneath North America. Temperatures at depths of the to ...
Terrestrial Planet Evolution in the Stagnant
... 1. Introduction Plate tectonics is only observed on Earth and is likely important to Earth’s uniquely clement surface conditions (e.g., Kasting and Catling, 2003). Other terrestrial planets in the Solar System (i.e., Mercury, Mars, and Venus) are generally considered to feature a rigid spherical she ...
... 1. Introduction Plate tectonics is only observed on Earth and is likely important to Earth’s uniquely clement surface conditions (e.g., Kasting and Catling, 2003). Other terrestrial planets in the Solar System (i.e., Mercury, Mars, and Venus) are generally considered to feature a rigid spherical she ...
Karson, J.A., and Lawrence, R.M., 1997.
... crustal structure is relatively minor. Where the magma budget is low, spreading is accommodated primarily by mechanical stretching and thinning of the existing crust and lithosphere. The deformation can be interrupted periodically by magmatic events resulting in complex geological relations between ...
... crustal structure is relatively minor. Where the magma budget is low, spreading is accommodated primarily by mechanical stretching and thinning of the existing crust and lithosphere. The deformation can be interrupted periodically by magmatic events resulting in complex geological relations between ...
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.