Pub-2010 - Caltech GPS
... There is a seamount chain (the Moonless Mountains) on the Pacific plate between the Murray and Clarion fracture zones that may have had a correlative chain, the Chumbia seamount ridge, on the now subducted Farallon plate (KEPPIE and MORAN-ZENTENO, 2005). The seamounts in this chain do not have flexu ...
... There is a seamount chain (the Moonless Mountains) on the Pacific plate between the Murray and Clarion fracture zones that may have had a correlative chain, the Chumbia seamount ridge, on the now subducted Farallon plate (KEPPIE and MORAN-ZENTENO, 2005). The seamounts in this chain do not have flexu ...
North America Dynamics and Western US Tectonics
... loads arising from crustal and uppermost mantle density structure. Edge forces are created directly by plate-toplate interaction across shared plate boundaries. Stress continuity requires that two plates in contact apply equal but opposite forces on each other across the shared boundary. Stress cont ...
... loads arising from crustal and uppermost mantle density structure. Edge forces are created directly by plate-toplate interaction across shared plate boundaries. Stress continuity requires that two plates in contact apply equal but opposite forces on each other across the shared boundary. Stress cont ...
CHAPTER 9 RECONNAISSANCE PHOTOGEOLOGIC MAP OF
... areas are probably much more intensely faulted than surviving surficial expressions of this faulting would suggest. These inherent biases notwithstanding, faults that juxtapose unconsolidated surficial deposits against bedrock or form prominent scarps in unconsolidated surficial deposits are more li ...
... areas are probably much more intensely faulted than surviving surficial expressions of this faulting would suggest. These inherent biases notwithstanding, faults that juxtapose unconsolidated surficial deposits against bedrock or form prominent scarps in unconsolidated surficial deposits are more li ...
Radiogenic Isotope Geochemistry of the Mantle
... the region occupied by the oceanic basalt data is often referred to as the “mantle array”. The second observation is that, although there is overlap, MORB have the lower 87Sr/86Sr ratios and highest εNd than OIB. Variations in radiogenic isotope ratios in basalts result from variations in parent-dau ...
... the region occupied by the oceanic basalt data is often referred to as the “mantle array”. The second observation is that, although there is overlap, MORB have the lower 87Sr/86Sr ratios and highest εNd than OIB. Variations in radiogenic isotope ratios in basalts result from variations in parent-dau ...
Initiation of Subduction Zones as a Consequence
... postulated reactivation is attractive, materials on both sides of a ridge or transform should be broadly similar as they are produced by similar processes in similar environments. Hence, it is unlikely that compositional buoyancy contrast across these weak zones would develop throughout their evolut ...
... postulated reactivation is attractive, materials on both sides of a ridge or transform should be broadly similar as they are produced by similar processes in similar environments. Hence, it is unlikely that compositional buoyancy contrast across these weak zones would develop throughout their evolut ...
- White Rose Research Online
... The Laptev Shelf offshore eastern Siberia represents a rare tectonic setting, comparable to that of the Woodlark Basin and Afar region, where an active oceanic spreading center, the Gakkel Ridge, approaches a continental margin (Figure 1). The North America-Eurasia plate boundary, corresponding to t ...
... The Laptev Shelf offshore eastern Siberia represents a rare tectonic setting, comparable to that of the Woodlark Basin and Afar region, where an active oceanic spreading center, the Gakkel Ridge, approaches a continental margin (Figure 1). The North America-Eurasia plate boundary, corresponding to t ...
Scholarly Interest Report
... provide access to a broad range of analytical approaches. Transfer of this knowledge through participation at national and international meetings will contribute to the overall benefit of many scientists studying the dynamics of convergent margins. ...
... provide access to a broad range of analytical approaches. Transfer of this knowledge through participation at national and international meetings will contribute to the overall benefit of many scientists studying the dynamics of convergent margins. ...
Tectonostratigraphic Succession and Development of the
... basement gneisses noted above, or in places separated from these, one finds yet another foreign element in the allochthon in the form of heterogeneous units of carbonate rocks, pelites, greenstone and local serpentinites (Plate 1). These are usually of lower metamorphic gråde than the crystalline gn ...
... basement gneisses noted above, or in places separated from these, one finds yet another foreign element in the allochthon in the form of heterogeneous units of carbonate rocks, pelites, greenstone and local serpentinites (Plate 1). These are usually of lower metamorphic gråde than the crystalline gn ...
Sect. 7-3 and 7-4 Practice Quiz
... ____ 18. The southern portion of Pangaea that broke apart about 180 million years ago is known as a. Pangaea. c. Gondwana. b. Panthalassa. d. Laurasia. ____ 19. Continental-oceanic collisions can also be called a. continental-continental collisions. c. divergent boundaries. b. oceanic-oceanic collis ...
... ____ 18. The southern portion of Pangaea that broke apart about 180 million years ago is known as a. Pangaea. c. Gondwana. b. Panthalassa. d. Laurasia. ____ 19. Continental-oceanic collisions can also be called a. continental-continental collisions. c. divergent boundaries. b. oceanic-oceanic collis ...
Plate Tectonics: GL209 Prof. John Tarney Lecture 5: Subduction
... is initiated either as a result of frictional heating at the subduction zone, or more likely through fluids released from the dehydrating subducting slab. The rising diapir then splits the arc in two and the two halves are progressively separated by seafloor spreading: ...
... is initiated either as a result of frictional heating at the subduction zone, or more likely through fluids released from the dehydrating subducting slab. The rising diapir then splits the arc in two and the two halves are progressively separated by seafloor spreading: ...
Crustal growth at active continental margins: Numerical
... The dynamics and melt sources for crustal growth at active continental margins are analyzed by using a 2D coupled petrological–thermomechanical numerical model of an oceanic-continental subduction zone. This model includes spontaneous slab retreat and bending, dehydration of subducted crust, aqueous ...
... The dynamics and melt sources for crustal growth at active continental margins are analyzed by using a 2D coupled petrological–thermomechanical numerical model of an oceanic-continental subduction zone. This model includes spontaneous slab retreat and bending, dehydration of subducted crust, aqueous ...
On the origin of noble gases in mantle plumes
... ®ux from the mantle (Jean-Baptiste 1992; Farley et al . 1995). This ®ux is measured with a large uncertainty, ca. 9 £ 107 mol yr¡1 . The emplacement rate of oceanic crust is close to 6 £ 1016 g yr¡1 . Consequently, the 4 He content of the undegassed magma should be 1500 £ 10¡12 mol g¡1 . Assuming th ...
... ®ux from the mantle (Jean-Baptiste 1992; Farley et al . 1995). This ®ux is measured with a large uncertainty, ca. 9 £ 107 mol yr¡1 . The emplacement rate of oceanic crust is close to 6 £ 1016 g yr¡1 . Consequently, the 4 He content of the undegassed magma should be 1500 £ 10¡12 mol g¡1 . Assuming th ...
Grade 8 Science Training Test Answer Key Question 1 Reporting
... The response provides an incorrect response for all three parts of the item. The response may have placed the incorrect stage of the star’s life cycle in each of the boxes. The response may have placed the incorrect and the correct stages of the star’s life cycle in each of the boxes (the response e ...
... The response provides an incorrect response for all three parts of the item. The response may have placed the incorrect stage of the star’s life cycle in each of the boxes. The response may have placed the incorrect and the correct stages of the star’s life cycle in each of the boxes (the response e ...
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... have been significantly thicker beneath what is oceanic ridge spreading at a half rate of 2-3 that these are generally sites of subduction initianow the frontal arc. cm/yr. These rates, patterns of faulting in the tion has been made by Casey and Dewey (1984) These parameters indicate that between 1, ...
... have been significantly thicker beneath what is oceanic ridge spreading at a half rate of 2-3 that these are generally sites of subduction initianow the frontal arc. cm/yr. These rates, patterns of faulting in the tion has been made by Casey and Dewey (1984) These parameters indicate that between 1, ...
Mathematical models of the Earth`s density structure and their
... layers. Kennett and Engdahl (1991) compiled the parameterized velocity model IASP91 that summarized travel time characteristics of main seismic phases. Kennett et al. (1995) compiled the AK135-f model by augmenting the AK135 velocity model with the density and Q-model of Montagner and Kennett (1995) ...
... layers. Kennett and Engdahl (1991) compiled the parameterized velocity model IASP91 that summarized travel time characteristics of main seismic phases. Kennett et al. (1995) compiled the AK135-f model by augmenting the AK135 velocity model with the density and Q-model of Montagner and Kennett (1995) ...
Effects of mantle and subduction-interface rheologies on slab
... Trench rollback has been a widely discussed phenomenon in recent years, and multiple studies have concentrated on various parameters that may influence trench migration and related aspects of slab deformation in the (upper) mantle. Here we concentrate on the effects of rheological description (yield ...
... Trench rollback has been a widely discussed phenomenon in recent years, and multiple studies have concentrated on various parameters that may influence trench migration and related aspects of slab deformation in the (upper) mantle. Here we concentrate on the effects of rheological description (yield ...
Numerical models of slab migration in continental collision zones
... Abstract. Continental collision is an intrinsic feature of plate tectonics. The closure of an oceanic basin leads to the onset of subduction of buoyant continental material, which slows down and eventually stops the subduction process. In natural cases, evidence of advancing margins has been recogni ...
... Abstract. Continental collision is an intrinsic feature of plate tectonics. The closure of an oceanic basin leads to the onset of subduction of buoyant continental material, which slows down and eventually stops the subduction process. In natural cases, evidence of advancing margins has been recogni ...
Exhumation of (ultra-)high-pressure terranes: concepts
... (U)HP terranes vary in outcrop size, tectonic and structural setting, and age, but they share a number of common features: a commonly upper- to mid-crustal origin, a volumetrically insignificant amount of mafic eclogite with respect to the volume of host felsic gneisses, metasediments or serpentinit ...
... (U)HP terranes vary in outcrop size, tectonic and structural setting, and age, but they share a number of common features: a commonly upper- to mid-crustal origin, a volumetrically insignificant amount of mafic eclogite with respect to the volume of host felsic gneisses, metasediments or serpentinit ...
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... that characterize the Caribbean and the easternmost Scotia Sea may be produced by viscous coupling to the predicted Pacific outflow through the gaps, and the Caribbean floor slopes in the predicted direction. If mantle outflow does pass through the gaps in the Pacific perimeter, it must pass beneath ...
... that characterize the Caribbean and the easternmost Scotia Sea may be produced by viscous coupling to the predicted Pacific outflow through the gaps, and the Caribbean floor slopes in the predicted direction. If mantle outflow does pass through the gaps in the Pacific perimeter, it must pass beneath ...
2307501 Basin analysis
... The heat flow measured above major strike-slip faults, such as those of the San Andreas system, is not significantly elevated compared to background values. The fact that observed heat flows are not significantly elevated suggests that major strike-slip faults are relatively weak structures set in a ...
... The heat flow measured above major strike-slip faults, such as those of the San Andreas system, is not significantly elevated compared to background values. The fact that observed heat flows are not significantly elevated suggests that major strike-slip faults are relatively weak structures set in a ...
Crustal collapse, mantle upwelling, and Cenozoic extension in the
... Hamilton and Myers, 1966; Stewart, 1978' Thompson and Burke, 1974; Wernicke, 1992; Zoback et al., 1981]. A summary here highlights some of the problems pertinent to ...
... Hamilton and Myers, 1966; Stewart, 1978' Thompson and Burke, 1974; Wernicke, 1992; Zoback et al., 1981]. A summary here highlights some of the problems pertinent to ...
Mantle convection models featuring plate tectonic behaviour
... global temperatures and heat flux and organize convective planform. Later studies featuring model plates with dynamically determined velocities discovered that the interaction between convection and plates could result in cyclic plate motion patterns and other time-dependent behaviour that was not ma ...
... global temperatures and heat flux and organize convective planform. Later studies featuring model plates with dynamically determined velocities discovered that the interaction between convection and plates could result in cyclic plate motion patterns and other time-dependent behaviour that was not ma ...
Geology
Geology (from the Greek γῆ, gē, i.e. ""earth"" and -λoγία, -logia, i.e. ""study of, discourse"") is an earth science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which they change. Geology can also refer generally to the study of the solid features of any celestial body (such as the geology of the Moon or Mars).Geology gives insight into the history of the Earth by providing the primary evidence for plate tectonics, the evolutionary history of life, and past climates. Geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, and for providing insights into past climate change. Geology also plays a role in geotechnical engineering and is a major academic discipline.