NORSK GEOLOGISK TIDSSKRIFT 45 DISTRIBUTION PATTERNS
... A study of the degree of enrichment and the range of enrichments observed in certain rock types provides some interesting results. Four groupings of terrestrial rocks have so far been suggested on the basis of equivalent degree of fractionation of the REE. In order of increasing enrichment in the li ...
... A study of the degree of enrichment and the range of enrichments observed in certain rock types provides some interesting results. Four groupings of terrestrial rocks have so far been suggested on the basis of equivalent degree of fractionation of the REE. In order of increasing enrichment in the li ...
Geological Society of America Bulletin
... and the allochthonous nature of ophiolites by the mid-1960s was instrumental in the formulation of the ophiolite model and the ophiolite– ocean crust analogy within the framework of the new plate-tectonic theory. The ophiolite suite became an ideal analogue to explain the seismic velocity structure ...
... and the allochthonous nature of ophiolites by the mid-1960s was instrumental in the formulation of the ophiolite model and the ophiolite– ocean crust analogy within the framework of the new plate-tectonic theory. The ophiolite suite became an ideal analogue to explain the seismic velocity structure ...
The Volume and Composition of Melt Generated
... impossible for magma to reach the surface at temperatures greater than about 1200°C? Geophysical and geochemical implications of this observation have, to our knowledge, never been fully explored, even though they could provide important constraints on temperature distribution in the mantle and on t ...
... impossible for magma to reach the surface at temperatures greater than about 1200°C? Geophysical and geochemical implications of this observation have, to our knowledge, never been fully explored, even though they could provide important constraints on temperature distribution in the mantle and on t ...
Remobilization of granitoid rocks through mafic recharge: evidence
... The trachytic hillock south of Gorai village also shows the mafic enclaves, which are fewer in number and generally small (up to a few centimeters; Fig. 2f). We collected samples (SG-HOST and SG-ENCL) here and also a loose rounded boulder (sample SG-BOUL) of a relatively fresh porphyritic basalt tha ...
... The trachytic hillock south of Gorai village also shows the mafic enclaves, which are fewer in number and generally small (up to a few centimeters; Fig. 2f). We collected samples (SG-HOST and SG-ENCL) here and also a loose rounded boulder (sample SG-BOUL) of a relatively fresh porphyritic basalt tha ...
poster technical sessions
... emphasis on the eastern Mediterranean region. Using the recent plate interactions among Africa, Arabia, and Eurasia, and their geological, geophysical, and geomorphological artifacts as the best natural cases, the conference is designed to explore crustal motions, mantle dynamics and GPS velocities ...
... emphasis on the eastern Mediterranean region. Using the recent plate interactions among Africa, Arabia, and Eurasia, and their geological, geophysical, and geomorphological artifacts as the best natural cases, the conference is designed to explore crustal motions, mantle dynamics and GPS velocities ...
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 ...
Rare Earth Elements Profile
... may be associated with quartz- and fluorite-bearing veins and breccia11 zones, skarns12 and pegmatites13. The economic potential of a REE deposit is strongly influenced by its mineralogy and the geological processes from which it has formed. Deposits which have a spatial and genetic association with ...
... may be associated with quartz- and fluorite-bearing veins and breccia11 zones, skarns12 and pegmatites13. The economic potential of a REE deposit is strongly influenced by its mineralogy and the geological processes from which it has formed. Deposits which have a spatial and genetic association with ...
When Rocks Get Hot
... by the thermal properties of rocks and their pore fluids (see “Physics of Temperature and Heat,” page 24). The most important of these properties are volumetric heat capacity, thermal conductivity and thermal diffusivity. Volumetric heat capacity specifies the amount of heat required to raise the temp ...
... by the thermal properties of rocks and their pore fluids (see “Physics of Temperature and Heat,” page 24). The most important of these properties are volumetric heat capacity, thermal conductivity and thermal diffusivity. Volumetric heat capacity specifies the amount of heat required to raise the temp ...
Do Now
... • Do Now: How many cups are in a gallon? • Vocab.: wavelength - distance from crest to crest in a wave • Summary: The difference between porosity and permeability is… Summary Answer: The difference between porosity and permeability is porosity is spaces in the ground and permeability is how fluid mo ...
... • Do Now: How many cups are in a gallon? • Vocab.: wavelength - distance from crest to crest in a wave • Summary: The difference between porosity and permeability is… Summary Answer: The difference between porosity and permeability is porosity is spaces in the ground and permeability is how fluid mo ...
Laboratory Title
... past 100 million years or so in a general northeast direction. This is drawing it closer to the Eurasian Plate, causing subduction where oceanic crust is converging with continental crust (e.g. portions of the central and eastern Mediterranean). The Antarctic Plate is a tectonic plate covering the c ...
... past 100 million years or so in a general northeast direction. This is drawing it closer to the Eurasian Plate, causing subduction where oceanic crust is converging with continental crust (e.g. portions of the central and eastern Mediterranean). The Antarctic Plate is a tectonic plate covering the c ...
The role of frictional strength on plate coupling at the subduction
... factor in controlling the dip angle of subduction and the structure of the forearc. In this paper, we investigate the role of the frictional strength of sediments and of the serpentinized peridotite on the evolution of convergent margins. In numerical models, we vary thickness of a serpentinized lay ...
... factor in controlling the dip angle of subduction and the structure of the forearc. In this paper, we investigate the role of the frictional strength of sediments and of the serpentinized peridotite on the evolution of convergent margins. In numerical models, we vary thickness of a serpentinized lay ...
IODP Proposal Cover Sheet
... The spatial and temporal evolution of arc magmas within a single oceanic arc is fundamental to understanding the initiation and evolution of oceanic arcs and the genesis of continental crust, which is one key objective of the IODP ISP. The Izu-Bonin-Mariana arc has been a target for this task for ma ...
... The spatial and temporal evolution of arc magmas within a single oceanic arc is fundamental to understanding the initiation and evolution of oceanic arcs and the genesis of continental crust, which is one key objective of the IODP ISP. The Izu-Bonin-Mariana arc has been a target for this task for ma ...
as a PDF - Dipartimento di Scienze della Terra
... ambiguous and useless for a number of reasons. The E- or NE-directed subduction zones have mostly continental lithosphere in the upper plate and the dip of the first 125 km is mostly constrained by the thickness and shape of the upper continental plate when present, and by the angle of the slab with ...
... ambiguous and useless for a number of reasons. The E- or NE-directed subduction zones have mostly continental lithosphere in the upper plate and the dip of the first 125 km is mostly constrained by the thickness and shape of the upper continental plate when present, and by the angle of the slab with ...
Origin of Mesoproterozoic A-type granites in Laurentia
... Granitic rocks are commonly used as a means to study chemical evolution of continental crust. In particular, their isotopic compositions reflect the relative contributions of mantle and crustal sources in their genesis. In Laurentia, a distinctive belt of Mesoproterozoic A-type or “anorogenic” grani ...
... Granitic rocks are commonly used as a means to study chemical evolution of continental crust. In particular, their isotopic compositions reflect the relative contributions of mantle and crustal sources in their genesis. In Laurentia, a distinctive belt of Mesoproterozoic A-type or “anorogenic” grani ...
extension systems - The Web site cannot be found
... mechanism, coeval lithospheric stretching and accretion of buoyant magma, is called rifting. It is called seafloor spreading once a rifted region becomes a plate boundary that creates new oceanic lithosphere as plates diverge from one another. The spreading centres shape elevated morphological forms ...
... mechanism, coeval lithospheric stretching and accretion of buoyant magma, is called rifting. It is called seafloor spreading once a rifted region becomes a plate boundary that creates new oceanic lithosphere as plates diverge from one another. The spreading centres shape elevated morphological forms ...
Subduction of diverging plates and the principles of slab window
... Consumption of an ocean basin by subduction commonly brings a sea-floor-spreading ridge toward a deep-sea trench. If plate divergence and convergence continue after the ridge intersects the subduction zone, a slab window forms between the subducted parts of the diverging oceanic plates, producing an ...
... Consumption of an ocean basin by subduction commonly brings a sea-floor-spreading ridge toward a deep-sea trench. If plate divergence and convergence continue after the ridge intersects the subduction zone, a slab window forms between the subducted parts of the diverging oceanic plates, producing an ...
The Central Asia collision zone: numerical present-day kinematics
... of the deformation related to the Arabia and India convergence against Eurasia. By combining geophysical and petrological information, the crust and upper mantle of the Zagros and the Himalaya-Tibetan orogens have been characterized from the thermal, compositional and seismological point of view. Fo ...
... of the deformation related to the Arabia and India convergence against Eurasia. By combining geophysical and petrological information, the crust and upper mantle of the Zagros and the Himalaya-Tibetan orogens have been characterized from the thermal, compositional and seismological point of view. Fo ...
MAJOR-ELEMENT CHEMISTRY OF PLUTONIC ROCK SUITES
... of volcanic rock suites has been well d o c u m e n t e d (Christiansen and Lipman, 1972; Martin and Piwinskii, 1972; Pearce et al., 1977). Plutonic suites have also been compared with volcanic suites of known tectonic setting, which allow indirect inferences to be made about the tectonic setting of ...
... of volcanic rock suites has been well d o c u m e n t e d (Christiansen and Lipman, 1972; Martin and Piwinskii, 1972; Pearce et al., 1977). Plutonic suites have also been compared with volcanic suites of known tectonic setting, which allow indirect inferences to be made about the tectonic setting of ...
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.