Seismic crustal structure between the Transylvanian
... In order to study the lithospheric structure in Romania a 450 km long WNW–ESE trending seismic refraction project was carried out in August/September 2001. It runs from the Transylvanian Basin across the East Carpathian Orogen and the Vrancea seismic region to the foreland areas with the very deep N ...
... In order to study the lithospheric structure in Romania a 450 km long WNW–ESE trending seismic refraction project was carried out in August/September 2001. It runs from the Transylvanian Basin across the East Carpathian Orogen and the Vrancea seismic region to the foreland areas with the very deep N ...
Can slab melting be caused by flat subduction
... and petrologic models, however, restrict partial melting to very young (15Ma) oceanic crust (typically at 60-SO km depth). Paradoxically, most of the known Pliocene-Quaternary adakite occurrences are related to subduction of 10-45 M a lithosphere,which should not be able to melt under normal subduct ...
... and petrologic models, however, restrict partial melting to very young (15Ma) oceanic crust (typically at 60-SO km depth). Paradoxically, most of the known Pliocene-Quaternary adakite occurrences are related to subduction of 10-45 M a lithosphere,which should not be able to melt under normal subduct ...
Recent Movements of the Juan de Fuca Plate System
... then spreadingrates along a ridge systemwould decreasesystematically toward the pole of rotation, fracture zones would always occur along small circlescenteredon the pole of rotation, and ridge segmentsand linear magneticanomalieswould alwaysfollow great circlespassingthrough the pole. Further, the ...
... then spreadingrates along a ridge systemwould decreasesystematically toward the pole of rotation, fracture zones would always occur along small circlescenteredon the pole of rotation, and ridge segmentsand linear magneticanomalieswould alwaysfollow great circlespassingthrough the pole. Further, the ...
Analogue modelling of continental collision: Influence of plate
... layers remains constant at varying depths, while in nature the strength of the ductile layers decreases exponentially (Ranalli, 1995, 1997). Consequently, temperature driven time–space variability of rheology during shortening cannot be accounted for, and we assume an initial homogenous plate rheolo ...
... layers remains constant at varying depths, while in nature the strength of the ductile layers decreases exponentially (Ranalli, 1995, 1997). Consequently, temperature driven time–space variability of rheology during shortening cannot be accounted for, and we assume an initial homogenous plate rheolo ...
`granitic` laver of the crust in the southern norwegian precambrian
... The concept of a granitic layer comprising the outer part of the earth's crust descends from both geologic and geophysical observations. Geologists have long noted the granitic nature of the deeply eroded Precambrian shields. The idea of a granitic layer in the crust was especially advanced by the r ...
... The concept of a granitic layer comprising the outer part of the earth's crust descends from both geologic and geophysical observations. Geologists have long noted the granitic nature of the deeply eroded Precambrian shields. The idea of a granitic layer in the crust was especially advanced by the r ...
Fold Fault Denudation
... As soon as a rock particle (loosened by one of the two weathering processes) moves, we call it erosion or mass wasting. Mass wasting is simply movement down slope due to gravity. Rock falls, slumps, and debris flows are all examples of mass wasting. We call it erosion if the rock particle is moved b ...
... As soon as a rock particle (loosened by one of the two weathering processes) moves, we call it erosion or mass wasting. Mass wasting is simply movement down slope due to gravity. Rock falls, slumps, and debris flows are all examples of mass wasting. We call it erosion if the rock particle is moved b ...
Tectonic speed limits from plate kinematic reconstructions (PDF
... (1975) quantified forces acting on tectonic plates, concluding that continents impede plate motion likely because of the higher viscosities beneath them and their possible anchoring role. However, it has been difficult to consistently map and characterise lithospheric thicknesses globally to isolate th ...
... (1975) quantified forces acting on tectonic plates, concluding that continents impede plate motion likely because of the higher viscosities beneath them and their possible anchoring role. However, it has been difficult to consistently map and characterise lithospheric thicknesses globally to isolate th ...
Plate motions, slab dynamics and back
... frame that is not attached to the plates, i.e., a terrestrial reference frame that gives each plate motion independently of mantle convection. Several possible absolute reference frames exist, based on various assumptions. The most commonly used is the fixed hotspots reference. Among all the existin ...
... frame that is not attached to the plates, i.e., a terrestrial reference frame that gives each plate motion independently of mantle convection. Several possible absolute reference frames exist, based on various assumptions. The most commonly used is the fixed hotspots reference. Among all the existin ...
Text
... Understanding how the Earth’s first continental land masses were generated is important because the processes responsible directly affected the evolution of the planet’s primordial silicate interior, and also its atmosphere and hydrosphere. Archaean continental crust is dominated by rocks of the tro ...
... Understanding how the Earth’s first continental land masses were generated is important because the processes responsible directly affected the evolution of the planet’s primordial silicate interior, and also its atmosphere and hydrosphere. Archaean continental crust is dominated by rocks of the tro ...
Plate motions, slab dynamics and back
... frame that is not attached to the plates, i.e., a terrestrial reference frame that gives each plate motion independently of mantle convection. Several possible absolute reference frames exist, based on various assumptions. The most commonly used is the fixed hotspots reference. Among all the existin ...
... frame that is not attached to the plates, i.e., a terrestrial reference frame that gives each plate motion independently of mantle convection. Several possible absolute reference frames exist, based on various assumptions. The most commonly used is the fixed hotspots reference. Among all the existin ...
Thesis pdf
... 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 ...
- Wiley Online Library
... Andean mountain building. The present-day crustal shortening in the Andes is clear from the GPS measurements, but the rate (30–40 mm/a) is higher than the geological shortening rate (<15 mm/a), suggesting that much of the present-day crustal shortening may recover during future earthquakes in the su ...
... Andean mountain building. The present-day crustal shortening in the Andes is clear from the GPS measurements, but the rate (30–40 mm/a) is higher than the geological shortening rate (<15 mm/a), suggesting that much of the present-day crustal shortening may recover during future earthquakes in the su ...
The Rocks Introduction: Igneous Rocks: Occurrence of Igneous Rocks:
... may be classified into four major groups : (1) equigranulartexture, (2)inequigranulartexture, (3) directive texture, and (4) intergrowth texture. Equigranular Texture. Igneous rocks containing mineral grains of more or less equal size are said to have an "equigranular texture".Equigranular textures ...
... may be classified into four major groups : (1) equigranulartexture, (2)inequigranulartexture, (3) directive texture, and (4) intergrowth texture. Equigranular Texture. Igneous rocks containing mineral grains of more or less equal size are said to have an "equigranular texture".Equigranular textures ...
alps vs apennines - Dipartimento di Scienze della Terra
... asymmetry has been ascribed either to the more efficient slab pull in the western Pacific (FORSYTH & UYEDA, 1975) or to the westward drift of the lithosphere relative to the underlying mantle (DOGLIONI et alii, 1999b). The same different interpretations have been used for differentiating the Alps an ...
... asymmetry has been ascribed either to the more efficient slab pull in the western Pacific (FORSYTH & UYEDA, 1975) or to the westward drift of the lithosphere relative to the underlying mantle (DOGLIONI et alii, 1999b). The same different interpretations have been used for differentiating the Alps an ...
full text - NWT Protected Area Strategy
... 8 values; these are A through H, corresponding to very high to not assessed. Confident Rankings have 4 values; 1 through 4, corresponding to highest to lowest level of confidence. REGIONAL GEOLOGICAL SETTING The Slave Geological Province (also termed Slave craton) is an Archean granite-greenstonetur ...
... 8 values; these are A through H, corresponding to very high to not assessed. Confident Rankings have 4 values; 1 through 4, corresponding to highest to lowest level of confidence. REGIONAL GEOLOGICAL SETTING The Slave Geological Province (also termed Slave craton) is an Archean granite-greenstonetur ...
Insights into extensional processes during magma assisted rifting
... in a broad zone of faulting and ductile stretching must transition towards a narrow zone of focused magmatic intrusion. The Main Ethiopian Rift (MER), part of the East African Rift System, is an ideal location to study this transition because it captures rifting processes during continental breakup. ...
... in a broad zone of faulting and ductile stretching must transition towards a narrow zone of focused magmatic intrusion. The Main Ethiopian Rift (MER), part of the East African Rift System, is an ideal location to study this transition because it captures rifting processes during continental breakup. ...
PDF
... Nevertheless, distinct isotopic compositions are readily inferred to identify old lithospheric material, which could be the continental crust, lithospheric mantle, or both. Zircon ages can also help distinguish juvenile versus reworked crust. This is because zircons are among the most refractory of ...
... Nevertheless, distinct isotopic compositions are readily inferred to identify old lithospheric material, which could be the continental crust, lithospheric mantle, or both. Zircon ages can also help distinguish juvenile versus reworked crust. This is because zircons are among the most refractory of ...
WalkerJ_JGR_95(B13)21483 - KU ScholarWorks
... rocks in the north-central Tibetan Plateau. The crustally derived rocks described here are an endmember componentof a wide mixing zone of hybrid magmas; the other end-memberforms mantlederived, potassicbasanitesand tephrites exposedin the central section of the Plio-Pleistocenefield. The composition ...
... rocks in the north-central Tibetan Plateau. The crustally derived rocks described here are an endmember componentof a wide mixing zone of hybrid magmas; the other end-memberforms mantlederived, potassicbasanitesand tephrites exposedin the central section of the Plio-Pleistocenefield. The composition ...
Generation of new continental crust by sublithospheric silicic
... this paper, which is focused to test Taylor's andesite model, an outline of the most debated topic in relation to the generation of the rocks forming the continental crust is given in the next section with the aim of offering a reference framework on the problem of continental crust generation. 2. T ...
... this paper, which is focused to test Taylor's andesite model, an outline of the most debated topic in relation to the generation of the rocks forming the continental crust is given in the next section with the aim of offering a reference framework on the problem of continental crust generation. 2. T ...
HEAT FLOW PATTERNS OF THE NORTH AMERICAN CONTINENT
... contoured based on the age of the lithosphere. As a result, most of the Atlantic Ocean off the eastern United States is shown to have a heat flow between 40 and 50 mWm-2, while further to the east, the theoretical values are between 50 and 60 mWm-2. The age corresponding to the 50 mWm-2 heat flow co ...
... contoured based on the age of the lithosphere. As a result, most of the Atlantic Ocean off the eastern United States is shown to have a heat flow between 40 and 50 mWm-2, while further to the east, the theoretical values are between 50 and 60 mWm-2. The age corresponding to the 50 mWm-2 heat flow co ...
Chapter 18 PowerPoint
... • The ash that spews from some volcanoes can form billowy clouds that travel around the world before raining back down to Earth. • In the last 10 000 years, more than 1500 different volcanoes have erupted, providing evidence that Earth is indeed geologically active. ...
... • The ash that spews from some volcanoes can form billowy clouds that travel around the world before raining back down to Earth. • In the last 10 000 years, more than 1500 different volcanoes have erupted, providing evidence that Earth is indeed geologically active. ...
ES Chapter 18
... • The ash that spews from some volcanoes can form billowy clouds that travel around the world before raining back down to Earth. • In the last 10 000 years, more than 1500 different volcanoes have erupted, providing evidence that Earth is indeed geologically active. ...
... • The ash that spews from some volcanoes can form billowy clouds that travel around the world before raining back down to Earth. • In the last 10 000 years, more than 1500 different volcanoes have erupted, providing evidence that Earth is indeed geologically active. ...
Mechanisms for the formation of ridge-axis topography at
... the active transform fault (Chen 1989). While each of these mechanisms could qualitatively explain certain aspects of the observed regularities in seafloor topography, none of these models had considered the new gravity and seismic data that provide direct evidence for significant variations in subs ...
... the active transform fault (Chen 1989). While each of these mechanisms could qualitatively explain certain aspects of the observed regularities in seafloor topography, none of these models had considered the new gravity and seismic data that provide direct evidence for significant variations in subs ...
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.