Papers presented to the Conference on Heat and Detachment in
... strength is negligible at depths where T is high and increases exponentially with decreasing depth. Flow laws are also highly dependent on rock composition, with a silicic crust much weaker than a mafic mantle. The failure criterion for a given depth in the lithosphere is determined by the weaker of ...
... strength is negligible at depths where T is high and increases exponentially with decreasing depth. Flow laws are also highly dependent on rock composition, with a silicic crust much weaker than a mafic mantle. The failure criterion for a given depth in the lithosphere is determined by the weaker of ...
Unit 1 The Ocean Basins
... least 3.8 billion years. It is easy to think that they are permanent features, ancient and unchanging. However, the only thing that is truly constant about ocean basins — and continents — is that they are always moving and changing. New oceans are born, and existing oceans change size and shape or d ...
... least 3.8 billion years. It is easy to think that they are permanent features, ancient and unchanging. However, the only thing that is truly constant about ocean basins — and continents — is that they are always moving and changing. New oceans are born, and existing oceans change size and shape or d ...
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... to the plate boundary coupling is expressed as both vertical and horizontal tectonics along crustal-scale faults such as the Denali Fault system. Results from this study will have both regional and broad scale tectonic implications. In particular, results from this project will help define what cons ...
... to the plate boundary coupling is expressed as both vertical and horizontal tectonics along crustal-scale faults such as the Denali Fault system. Results from this study will have both regional and broad scale tectonic implications. In particular, results from this project will help define what cons ...
Igneous Rocks - AC Reynolds High
... most abundant and has the greatest effect on magma characteristics. As summarized in Table 5-1, magmas are classified as basaltic, andesitic, and rhyolitic, based on the amount of SiO2 they contain. Silica content affects melting temperature and also impacts how quickly magma flows. ...
... most abundant and has the greatest effect on magma characteristics. As summarized in Table 5-1, magmas are classified as basaltic, andesitic, and rhyolitic, based on the amount of SiO2 they contain. Silica content affects melting temperature and also impacts how quickly magma flows. ...
the Scotia Sea and the Caribbean
... This thesis deals with new plate reconstruction models of the Scotia Sea and the Caribbean - regions that share very complicated plate tectonic histories. Each model and their implications are discussed, e.g. it is shown that the Central Scotia Sea is most likely not a Mesozoic plate fragment as sug ...
... This thesis deals with new plate reconstruction models of the Scotia Sea and the Caribbean - regions that share very complicated plate tectonic histories. Each model and their implications are discussed, e.g. it is shown that the Central Scotia Sea is most likely not a Mesozoic plate fragment as sug ...
4 Volcanoes and Plate Tectonics
... expect volcanoes to occur along the MidAtlantic Ridge? (Yes, this is a diverging boundary.) learning modality: visual ...
... expect volcanoes to occur along the MidAtlantic Ridge? (Yes, this is a diverging boundary.) learning modality: visual ...
Trace element and isotope geochemistry of gabbro
... Relics of igneous textures, mineral and bulk-rock compositional variations indicate a comagmatic origin for the gabbro-derived granulites. They can be generally recognized as cumulitic rocks with negligible amounts of residual trapped liquid, on the basis of low SiO2/A1203 ratios (Kempton and Harmon ...
... Relics of igneous textures, mineral and bulk-rock compositional variations indicate a comagmatic origin for the gabbro-derived granulites. They can be generally recognized as cumulitic rocks with negligible amounts of residual trapped liquid, on the basis of low SiO2/A1203 ratios (Kempton and Harmon ...
Classification of Alberta Landforms
... actions or effects of the application of forces over gradients - such as wind, rain, waves, etc. Where the applied forces exceed the resistance of the earth's materials (e.g., soil, rocks), deformation or change occurs. Therefore, landforms are the result of the operation of various processes. Some ...
... actions or effects of the application of forces over gradients - such as wind, rain, waves, etc. Where the applied forces exceed the resistance of the earth's materials (e.g., soil, rocks), deformation or change occurs. Therefore, landforms are the result of the operation of various processes. Some ...
Fig. 1
... These encapsulate active volcanoes (Biggs et al., 2011), aligned monogenetic cones (e.g., Ebinger and Casey, 2001; Mazzarini, 2008; Williams et al., 2004), and small-offset faults striking perpendicular to the direction of extension (Fig. 2) (e.g., Agostini et al., 2011a,b; Corti, 2008, 2009; Haywar ...
... These encapsulate active volcanoes (Biggs et al., 2011), aligned monogenetic cones (e.g., Ebinger and Casey, 2001; Mazzarini, 2008; Williams et al., 2004), and small-offset faults striking perpendicular to the direction of extension (Fig. 2) (e.g., Agostini et al., 2011a,b; Corti, 2008, 2009; Haywar ...
Dynamics of intraoceanic subduction initiation
... Abstract Analyzing subduction initiation is key for understanding the coupling between plate tectonics and the underlying mantle. Here we focus on suprasubduction zone (SSZ) ophiolites and how their formation links to intraoceanic subduction initiation in an absolute plate motion frame. SSZ ophiolit ...
... Abstract Analyzing subduction initiation is key for understanding the coupling between plate tectonics and the underlying mantle. Here we focus on suprasubduction zone (SSZ) ophiolites and how their formation links to intraoceanic subduction initiation in an absolute plate motion frame. SSZ ophiolit ...
Azimuthal anisotropy and phase velocity beneath Iceland
... surface wave tomography on a global scale [20] shows complex, frequency-dependent anisotropy in the North Atlantic, but does not have su⁄cient lateral resolution to determine anisotropy beneath Iceland. Bjarnason et al. [21] measured shearwave splitting at the ICEMELT stations and explained their ob ...
... surface wave tomography on a global scale [20] shows complex, frequency-dependent anisotropy in the North Atlantic, but does not have su⁄cient lateral resolution to determine anisotropy beneath Iceland. Bjarnason et al. [21] measured shearwave splitting at the ICEMELT stations and explained their ob ...
Plate-Tectonics A review
... • Rocks of same age and similar characteristics on different continents • Distribution of similar plants and animals on different continents (how did they cross the ocean) ...
... • Rocks of same age and similar characteristics on different continents • Distribution of similar plants and animals on different continents (how did they cross the ocean) ...
sedimentation and sedimentary rocks
... Sediments accumulation takes place generally in topographic depressions, generically referred to as "sedimentary basins", the most important being the epicontinental and oceanic seas. Emergent lands are generally sites of erosion but significant sediments accumulation occur in lakes, alluvial plains ...
... Sediments accumulation takes place generally in topographic depressions, generically referred to as "sedimentary basins", the most important being the epicontinental and oceanic seas. Emergent lands are generally sites of erosion but significant sediments accumulation occur in lakes, alluvial plains ...
Magma Genesis and Mantle Dynamics at the Harrat Ash
... Israel (Mor, 1993; Heimann et al., 1996; Weinstein et al., 2006). The numbers give K/Ar and 40Ar/39Ar ages in million years. Data sources: Giannérini et al. (1988), Mouty et al. (1992), Sharkov et al. (1994) and this study. ...
... Israel (Mor, 1993; Heimann et al., 1996; Weinstein et al., 2006). The numbers give K/Ar and 40Ar/39Ar ages in million years. Data sources: Giannérini et al. (1988), Mouty et al. (1992), Sharkov et al. (1994) and this study. ...
Clutch tectonics and the partial attachment of lithospheric layers
... these sub-horizontal shear zones act as partial attachment zones between lithospheric layers. Two cases are possible: 1) Top-driven clutch systems, such as in extensional core complexes, in which kinematics are controlled by gravitational forces; or 2) Bottom-driven clutch systems in which kinematic ...
... these sub-horizontal shear zones act as partial attachment zones between lithospheric layers. Two cases are possible: 1) Top-driven clutch systems, such as in extensional core complexes, in which kinematics are controlled by gravitational forces; or 2) Bottom-driven clutch systems in which kinematic ...
Subduction and eduction of continental crust: major mechanisms
... During continental collision in the middle Silurian, the thickness of the lithosphere under the Caledonides of S. Norway was doubled by subduction of the western margin of Baltica, including the Western Gneiss Region, under Laurentia. Crustal rocks of the Baltic plate reached sub-Moho depths of near ...
... During continental collision in the middle Silurian, the thickness of the lithosphere under the Caledonides of S. Norway was doubled by subduction of the western margin of Baltica, including the Western Gneiss Region, under Laurentia. Crustal rocks of the Baltic plate reached sub-Moho depths of near ...
Geophysics
Geophysics /dʒiːoʊfɪzɪks/ is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and composition; its dynamics and their surface expression in plate tectonics, the generation of magmas, volcanism and rock formation. However, modern geophysics organizations use a broader definition that includes the water cycle including snow and ice; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere and solar-terrestrial relations; and analogous problems associated with the Moon and other planets.Although geophysics was only recognized as a separate discipline in the 19th century, its origins go back to ancient times. The first magnetic compasses were made from lodestones, while more modern magnetic compasses played an important role in the history of navigation. The first seismic instrument was built in 132 BC. Isaac Newton applied his theory of mechanics to the tides and the precession of the equinox; and instruments were developed to measure the Earth's shape, density and gravity field, as well as the components of the water cycle. In the 20th century, geophysical methods were developed for remote exploration of the solid Earth and the ocean, and geophysics played an essential role in the development of the theory of plate tectonics.Geophysics is applied to societal needs, such as mineral resources, mitigation of natural hazards and environmental protection. Geophysical survey data are used to analyze potential petroleum reservoirs and mineral deposits, locate groundwater, find archaeological relics, determine the thickness of glaciers and soils, and assess sites for environmental remediation.