Geology and Geophysics (GEOS)
... Concepts and techniques of geophysics including origin of the Earth, its structure and large scale dynamic processes responsible for its surface features. Geophysical techniques including seismology, gravity and magnetic methods are discussed along with measurements of the Earth's thermal structure, ...
... Concepts and techniques of geophysics including origin of the Earth, its structure and large scale dynamic processes responsible for its surface features. Geophysical techniques including seismology, gravity and magnetic methods are discussed along with measurements of the Earth's thermal structure, ...
ABSTRACT The gneiss complex around and north of Pouso Alegre
... doubts such as arise from our ignorance of the role of physical properties of crustal materiais, tectonics and heat flow. Although some of these parameters have been taken into account in many of the models, they are far from explaining everything. This is of course impossible, since the focus of sc ...
... doubts such as arise from our ignorance of the role of physical properties of crustal materiais, tectonics and heat flow. Although some of these parameters have been taken into account in many of the models, they are far from explaining everything. This is of course impossible, since the focus of sc ...
palaeozoic porphyry molybdenum-tungsten deposit in the myszków
... porphyry copper deposits. The deposit at Myszków consists mainly of stockwork veins; skarn minerals are uncommon. Several substages of mineral deposition have been identified in the Myszków area, five of which are closely related to formation of this porphyry deposit. The results of a factor analyse ...
... porphyry copper deposits. The deposit at Myszków consists mainly of stockwork veins; skarn minerals are uncommon. Several substages of mineral deposition have been identified in the Myszków area, five of which are closely related to formation of this porphyry deposit. The results of a factor analyse ...
Exploring Geology: What-To-Know List
... Describe the different kinds of energy that impact Earth from the outside, and what effects they have on our planet. List the different kinds of energy that arise within Earth’s interior and explain their origins. Sketch and explain how Earth’s surface and atmosphere interact with solar energy ...
... Describe the different kinds of energy that impact Earth from the outside, and what effects they have on our planet. List the different kinds of energy that arise within Earth’s interior and explain their origins. Sketch and explain how Earth’s surface and atmosphere interact with solar energy ...
Lower Continental Crust. - UCSB Earth Science
... OF CONTINENTAL CRUST Earth’s continental crust is widely believed to be andesitic to dacitic, with 57 to 66 wt% SiO2 (e.g., Rudnick & Gao 2003, 2014), distinct from mafic oceanic crust, with 48 to 52 wt% SiO2 , and from upper mantle residual peridotites, with <46 wt% SiO2 . Compared with oceanic crus ...
... OF CONTINENTAL CRUST Earth’s continental crust is widely believed to be andesitic to dacitic, with 57 to 66 wt% SiO2 (e.g., Rudnick & Gao 2003, 2014), distinct from mafic oceanic crust, with 48 to 52 wt% SiO2 , and from upper mantle residual peridotites, with <46 wt% SiO2 . Compared with oceanic crus ...
Ophiolite concept and its evolution
... European ophiolite concept (Coleman, 1977). Thayer had written this paper for the volume on “Ultramafic and Related Rocks,” edited by Peter J. Wyllie (1967), to explain how the gabbro, diabase, and other leucocratic rocks in alpine-type peridotites could have originated from a single primary peridot ...
... European ophiolite concept (Coleman, 1977). Thayer had written this paper for the volume on “Ultramafic and Related Rocks,” edited by Peter J. Wyllie (1967), to explain how the gabbro, diabase, and other leucocratic rocks in alpine-type peridotites could have originated from a single primary peridot ...
Orogens and slabs vs. their direction of subduction
... the viscosity value at the 670 km discontinuity between upper and lower mantle ŽHager, 1990. make the mantle adjacent to the seismically detectable slab an isolated system, with inhibited communication among eastern and western sectors of the slab, and the upper and lower mantle underneath. This sup ...
... the viscosity value at the 670 km discontinuity between upper and lower mantle ŽHager, 1990. make the mantle adjacent to the seismically detectable slab an isolated system, with inhibited communication among eastern and western sectors of the slab, and the upper and lower mantle underneath. This sup ...
Controls on back-arc basin formation
... basin formation and to explain their temporal and spatial distribution. Our new data set of subduction and back-arc basin parameters uses a new set of paleo-oceanic age grids (Müller et al., 2005) associated with a moving Atlantic-Indian Ocean hot spot reference frame (O’Neill et al., 2005). The pl ...
... basin formation and to explain their temporal and spatial distribution. Our new data set of subduction and back-arc basin parameters uses a new set of paleo-oceanic age grids (Müller et al., 2005) associated with a moving Atlantic-Indian Ocean hot spot reference frame (O’Neill et al., 2005). The pl ...
Mechanisms of continental subduction and exhumation of HP and
... rocks are treated in conjunction with synthetic P–T–t paths predicted from thermo-mechanical numerical models of convergent processes. This provides key validation of the inferred concepts of convergent dynamics and thermo-mechanical properties of oceanic and continental subduction zones (e.g., Yama ...
... rocks are treated in conjunction with synthetic P–T–t paths predicted from thermo-mechanical numerical models of convergent processes. This provides key validation of the inferred concepts of convergent dynamics and thermo-mechanical properties of oceanic and continental subduction zones (e.g., Yama ...
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... fractionation of mafic minerals (Table 2). Some Ueno basalt compositions could have been in equilibrium with upper-mantle peridotite (Nakano, 1994; Kimura & Yoshida, 1999). Sub-alkaline basalt from Kitazawa has >10% MgO, high Ni and Cr contents, and contains Fo90 olivine, and so is thought to be pri ...
... fractionation of mafic minerals (Table 2). Some Ueno basalt compositions could have been in equilibrium with upper-mantle peridotite (Nakano, 1994; Kimura & Yoshida, 1999). Sub-alkaline basalt from Kitazawa has >10% MgO, high Ni and Cr contents, and contains Fo90 olivine, and so is thought to be pri ...
Late Palaeozoic lam pro phyres and as so ci ated mafic subvolcanic
... Lamprophyric magmatism in the Sudetes, in the eastern part of the European Variscides, occurred during a period of post-collisional extension in the Carboniferous. The lamprophyres (minettes, vogesites, spessartites, kersantites) and associated mafic rocks (monzonites, micromonzodiorites) were empla ...
... Lamprophyric magmatism in the Sudetes, in the eastern part of the European Variscides, occurred during a period of post-collisional extension in the Carboniferous. The lamprophyres (minettes, vogesites, spessartites, kersantites) and associated mafic rocks (monzonites, micromonzodiorites) were empla ...
Yin and yang of continental crust creation and destruction by plate
... Our perspective, that continental crust is destroyed as well as created, may be difficult for some to accept. Western geoscientists are imbued by the idea of ‘progress’ implicit in discussions of crustal ‘evolution’ (generally taken to be progressive increase in crustal volume), but this perspective ...
... Our perspective, that continental crust is destroyed as well as created, may be difficult for some to accept. Western geoscientists are imbued by the idea of ‘progress’ implicit in discussions of crustal ‘evolution’ (generally taken to be progressive increase in crustal volume), but this perspective ...
Seamounts – characteristics, formation, mineral deposits and
... is a fraction of a larger global database of 50,000 or more seamounts. A compilation of bathymetric and altimetric data suggested ~125,000 seamounts (h>1000m) but could be between 45,000-350,000; while smaller seamounts (h<100m) could be 25 million (8-80 million) (Wessel et al., 2010). Recently, by ...
... is a fraction of a larger global database of 50,000 or more seamounts. A compilation of bathymetric and altimetric data suggested ~125,000 seamounts (h>1000m) but could be between 45,000-350,000; while smaller seamounts (h<100m) could be 25 million (8-80 million) (Wessel et al., 2010). Recently, by ...
Near-Ultrahigh Pressure Processing of Continental Crust: Miocene
... compositions were measured at Boston University using the remains of thin-section billets. This is not ideal because the samples are contaminated with epoxy from thin-section impregnation, and some include bits of host lava. Billets were first abraded with silicon carbide to remove as much as possib ...
... compositions were measured at Boston University using the remains of thin-section billets. This is not ideal because the samples are contaminated with epoxy from thin-section impregnation, and some include bits of host lava. Billets were first abraded with silicon carbide to remove as much as possib ...
Mantle Convection in the Earth and Planets - U
... topography, gravitational field, geodynamo, climate system, cycles of glaciation, biological evolution, and formation of mineral and hydrocarbon resources. It is the primary mechanism for the transport of heat from the Earth’s deep interior to its surface. Mantle convection is the fundamental cause o ...
... topography, gravitational field, geodynamo, climate system, cycles of glaciation, biological evolution, and formation of mineral and hydrocarbon resources. It is the primary mechanism for the transport of heat from the Earth’s deep interior to its surface. Mantle convection is the fundamental cause o ...
Subduction kinematics and dynamic constraints
... (WNW), where the slab is a right-lateral ramp of the subduction, and it dips to the NNE. The W-directed slabs are generally very steep (up to 90°) and deep, apart few cases as Japan. They have a cogenetic backarc basin, and the related single verging accretionary prism has low elevation (e.g., Barba ...
... (WNW), where the slab is a right-lateral ramp of the subduction, and it dips to the NNE. The W-directed slabs are generally very steep (up to 90°) and deep, apart few cases as Japan. They have a cogenetic backarc basin, and the related single verging accretionary prism has low elevation (e.g., Barba ...
Evolution of the continental crust
... 4.7% MgO (Table 1), a composition not likely to have been in equilibrium with the upper mantle. Most models for the generation of the continental crust therefore involve at least two stages of differentiation—the extraction of basaltic magma from the mantle and the remelting or fractional crystalliz ...
... 4.7% MgO (Table 1), a composition not likely to have been in equilibrium with the upper mantle. Most models for the generation of the continental crust therefore involve at least two stages of differentiation—the extraction of basaltic magma from the mantle and the remelting or fractional crystalliz ...
IODP Proposal Cover Sheet
... in continental creation. Bulk continental crust is andesitic in composition, but the primary melt extracted from the upper mantle in subduction zones is basaltic. We still do not understand what causes this compositional change’ (p.67). In order to explain the intermediate composition of the bulk co ...
... in continental creation. Bulk continental crust is andesitic in composition, but the primary melt extracted from the upper mantle in subduction zones is basaltic. We still do not understand what causes this compositional change’ (p.67). In order to explain the intermediate composition of the bulk co ...
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.