Earth,Tests,Ch12
... would you expect similar interior structures on Venus or Mars? What major geological processes on those planets should be similar to those on Earth? Diff: 3 ...
... would you expect similar interior structures on Venus or Mars? What major geological processes on those planets should be similar to those on Earth? Diff: 3 ...
Lamarque_Arlita_SKS_RF_GJI_201
... The Terre Adélie and George V Land (East Antarctica) represent key areas for understanding tectonic relationships between terranes forming the Neoarchean-Palaeoproterozoic Terre Adélie Craton (TAC) and the neighbouring lithospheric blocks, together with the nature of its boundary. This region that ...
... The Terre Adélie and George V Land (East Antarctica) represent key areas for understanding tectonic relationships between terranes forming the Neoarchean-Palaeoproterozoic Terre Adélie Craton (TAC) and the neighbouring lithospheric blocks, together with the nature of its boundary. This region that ...
Mantle convection in the Middle East: Reconciling Afar - HAL-Insu
... 2006 and Moucha and Forte, 2011; Faccenna and Becker, 2010; Forte et al., 2010; Becker and Faccenna, 2011 and Komut et al., 2012). Volcanism is diffuse over the region and mainly focused on the large Ethiopian–Yemen igneous province (Fig. 1b). Intraplate volcanism is also present in Syria–Jordan and ...
... 2006 and Moucha and Forte, 2011; Faccenna and Becker, 2010; Forte et al., 2010; Becker and Faccenna, 2011 and Komut et al., 2012). Volcanism is diffuse over the region and mainly focused on the large Ethiopian–Yemen igneous province (Fig. 1b). Intraplate volcanism is also present in Syria–Jordan and ...
An Iceland hotspot saga
... shorter than that to East Greenland, which qualitatively agrees with a westwards drifting plate boundary. According to the hotspot models HS2-Nuvel1 (Gripp and Gorden, 1990) or HS3-Nuvel1A this drift is 16–18 mm/yr to the west. With the I-hotspot source shifted ∼150 km to the east of the main trend ...
... shorter than that to East Greenland, which qualitatively agrees with a westwards drifting plate boundary. According to the hotspot models HS2-Nuvel1 (Gripp and Gorden, 1990) or HS3-Nuvel1A this drift is 16–18 mm/yr to the west. With the I-hotspot source shifted ∼150 km to the east of the main trend ...
Introduction - San Francisco State University
... underwater lava flows. The radiolarian chert was deposited on top of the greenstone over millions of years, as the Farallon plate moved east. The sandstone and shale unit was then deposited on top of the chert as the Farallon plate neared North America. As these rocks entered into the Franciscan su ...
... underwater lava flows. The radiolarian chert was deposited on top of the greenstone over millions of years, as the Farallon plate moved east. The sandstone and shale unit was then deposited on top of the chert as the Farallon plate neared North America. As these rocks entered into the Franciscan su ...
Geoelectric structure in the Andaman Islands using magnetotelluric studies
... layer to the west of Rangat (site 4) with a conductance ranging between 200 and 1000 Siemens corresponding to the Andaman Flysch. This is underlain by a 40–50 km thick crust with a resistivity in excess of 10000 -m. The irregular shape of the crustal block in this region is indicative of the intens ...
... layer to the west of Rangat (site 4) with a conductance ranging between 200 and 1000 Siemens corresponding to the Andaman Flysch. This is underlain by a 40–50 km thick crust with a resistivity in excess of 10000 -m. The irregular shape of the crustal block in this region is indicative of the intens ...
occurrence of the ocean and its evolution toward an
... basaltic magmas erupting along the fault systems engendered flood basalt occurrences, which may extend over large areas, like those from Deccan that occupy one-third of the Indian territory (Hatch et al., 1961), or the Karroo basalt complex in South Africa, which extends over an area of up to 5,000 ...
... basaltic magmas erupting along the fault systems engendered flood basalt occurrences, which may extend over large areas, like those from Deccan that occupy one-third of the Indian territory (Hatch et al., 1961), or the Karroo basalt complex in South Africa, which extends over an area of up to 5,000 ...
... Cosmochemists get age information from samarium (Sm) and neodymium (Nd), two rare earth elements. Sm has two radioactive elements. 147Sm decays to 143Nd with a long half-life of 106 billion years. On the other hand, 146Sm decays to 142Nd with a much shorter half-life, only 103 million years. 146Sm d ...
Physics and Chemistry of Deep Continental Crust
... effective in communication. These terms are hence defined below. We use the term ‘foundering’ when no specific mechanism is implied. A distinction, however, must be made between foundering from other convective processes, such as subduction of oceanic lithosphere. Subduction is related to plate tect ...
... effective in communication. These terms are hence defined below. We use the term ‘foundering’ when no specific mechanism is implied. A distinction, however, must be made between foundering from other convective processes, such as subduction of oceanic lithosphere. Subduction is related to plate tect ...
Degree-one mantle convection: Dependence on
... [5] A fundamental question is whether observed large wavelength mantle flow results from the complicated brittleelastic physics of the lithosphere or whether the material properties of the mantle (i.e., rheology, phase transitions, chemical heterogeneity) are the cause. [6] It has been shown that th ...
... [5] A fundamental question is whether observed large wavelength mantle flow results from the complicated brittleelastic physics of the lithosphere or whether the material properties of the mantle (i.e., rheology, phase transitions, chemical heterogeneity) are the cause. [6] It has been shown that th ...
35. Interpretation of Seismic-Reflection Data of the Middle America
... Guatemala, together with published well information from the outer shelf and Leg 67 drilling results from the toe of the slope indicate that imbricate slices of oceanic crust were emplaced in the landward slope offshore Guatemala in the Paleocene or early Eocene. Since that time, sediment apparently ...
... Guatemala, together with published well information from the outer shelf and Leg 67 drilling results from the toe of the slope indicate that imbricate slices of oceanic crust were emplaced in the landward slope offshore Guatemala in the Paleocene or early Eocene. Since that time, sediment apparently ...
seismic potential associated with subduction in the northwestern
... Seismic quiescence. Although weakly coupled subduction zones may display a total absence of major earthquakes, they still have relatively high seismic activity at small magnitudes. Benioff-W adati zones capable of truly great earthquakes, however, often show significant periods of extremely low seis ...
... Seismic quiescence. Although weakly coupled subduction zones may display a total absence of major earthquakes, they still have relatively high seismic activity at small magnitudes. Benioff-W adati zones capable of truly great earthquakes, however, often show significant periods of extremely low seis ...
Configuration of subducting Philippine Sea plate and crustal
... about 20–26 km. Below this depth, the upper boundary of the subducting Philippine Sea plate is distorted over a depth range of 26–33 km. A large variation of the reflected-wave amplitude with depth along the subducting plate was observed. At a depth of about 20–26 km, the amplitude of the reflected ...
... about 20–26 km. Below this depth, the upper boundary of the subducting Philippine Sea plate is distorted over a depth range of 26–33 km. A large variation of the reflected-wave amplitude with depth along the subducting plate was observed. At a depth of about 20–26 km, the amplitude of the reflected ...
The late Paleozoic to Cainozoic intraplate deformation in
... Abstract. Several stages of intraplate deformation are distinguished in North Arabia from the Late Paleozoic to Cainozoic. The major rifting episodes occured in the Late Carboniferous-Permian, Middle-Late Triassic and at the end of the Early Cretaceous. None of them shows clear connection with plume ...
... Abstract. Several stages of intraplate deformation are distinguished in North Arabia from the Late Paleozoic to Cainozoic. The major rifting episodes occured in the Late Carboniferous-Permian, Middle-Late Triassic and at the end of the Early Cretaceous. None of them shows clear connection with plume ...
hall_church_comments
... aware that equivalents of the high-Ti series have been found in the plutonic sequence, since even the younger rocks of the Intrusive Sequence, characterized by the crystallization sequence 01-Cpx-Plag-Opx-Amph, contain low-Ti clinopyroxenes (Dion1987; Thibault 1987). The even more primitive plutonic ...
... aware that equivalents of the high-Ti series have been found in the plutonic sequence, since even the younger rocks of the Intrusive Sequence, characterized by the crystallization sequence 01-Cpx-Plag-Opx-Amph, contain low-Ti clinopyroxenes (Dion1987; Thibault 1987). The even more primitive plutonic ...
Negredo et al. Pamir subduction, EPSL, 259, 2007
... the India–Eurasia collision zone, with steep northward subduction of Indian lithosphere beneath the Hindu Kush and southward subduction of Asian lithosphere under the Pamir. We investigate the geometry and the timing of these subduction processes. Seismic tomography images are used to constrain the ...
... the India–Eurasia collision zone, with steep northward subduction of Indian lithosphere beneath the Hindu Kush and southward subduction of Asian lithosphere under the Pamir. We investigate the geometry and the timing of these subduction processes. Seismic tomography images are used to constrain the ...
Continental crust under compression: A seismic refraction study of
... distribution in age and origin of basement rocks of South Island reveals two very distinct metamorphic belts, the Western and Eastern Province, which are joined by a suture called the Median Tectonic Zone (MTZ, Figure 2) [Landis and Coombs, 1967; Bradshaw, 1993; Kimbrough et al., 1993]. The 450 km ...
... distribution in age and origin of basement rocks of South Island reveals two very distinct metamorphic belts, the Western and Eastern Province, which are joined by a suture called the Median Tectonic Zone (MTZ, Figure 2) [Landis and Coombs, 1967; Bradshaw, 1993; Kimbrough et al., 1993]. The 450 km ...
Crust and upper mantle of the western Mediterranean – Constraints
... incorporation of body and multi-mode surface waves in the period range from 12–150 s allows us to jointly resolve crustal and mantle structures, including the Guadalquivir, Tajo and Ebro basins at shallow depth, as well as the western Mediterranean subduction system in the transition zone. No mantle ...
... incorporation of body and multi-mode surface waves in the period range from 12–150 s allows us to jointly resolve crustal and mantle structures, including the Guadalquivir, Tajo and Ebro basins at shallow depth, as well as the western Mediterranean subduction system in the transition zone. No mantle ...
Mantle plumes, plumes and “plumes”: do we
... 4. Oceanic island basalts are enriched in incompatible elements compared with depleted mid-oceanic ridge basalts, hence source is primitive in composition (Earth’s lower mantle); 5. Hot spots lie atop of localized thermal upwellings referred to as plumes; 6. Plumes represent the major part of uprais ...
... 4. Oceanic island basalts are enriched in incompatible elements compared with depleted mid-oceanic ridge basalts, hence source is primitive in composition (Earth’s lower mantle); 5. Hot spots lie atop of localized thermal upwellings referred to as plumes; 6. Plumes represent the major part of uprais ...
Paper - EarthByte
... al., 2009; Keller, 2004) have added additional picks using tectonic trends i.e., abyssal hills from high quality multibeam data. In these cases, two additional picks are identified on the edges of the swath multibeam to define three picks from a single voyage track. The identification method for eac ...
... al., 2009; Keller, 2004) have added additional picks using tectonic trends i.e., abyssal hills from high quality multibeam data. In these cases, two additional picks are identified on the edges of the swath multibeam to define three picks from a single voyage track. The identification method for eac ...
The early interaction between the Caribbean Plateau and the NW
... shortly after the eruption of the plateau, resulting in the formation of part of the Great Arc of the Caribbean. Earlier interpretations, which proposed that the Pujilı́ Granite represents fragments of Triassic plutons that are currently exposed in the Eastern Cordillera, and became incorporated int ...
... shortly after the eruption of the plateau, resulting in the formation of part of the Great Arc of the Caribbean. Earlier interpretations, which proposed that the Pujilı́ Granite represents fragments of Triassic plutons that are currently exposed in the Eastern Cordillera, and became incorporated int ...
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.