KENT C. CONDIE
... The parental theory of plate tectonics, seafloor spreading, states that new lithosphere is formed at ocean ridges and moves away from ridge axes with a motion like that of a conveyor belt as new lithosphere fills in the resulting crack or rift. The mosaic of plates, which range from 50 to over 200 k ...
... The parental theory of plate tectonics, seafloor spreading, states that new lithosphere is formed at ocean ridges and moves away from ridge axes with a motion like that of a conveyor belt as new lithosphere fills in the resulting crack or rift. The mosaic of plates, which range from 50 to over 200 k ...
Origin and consequences of western Mediterranean subduction
... the Pyrenees [e.g., Dewey et al., 1989; Rosenbaum et al., 2002b; Sibuet et al., 2004; Vissers and Meijer, 2012a, 2012b]. Following marine magnetic anomaly constraints of the Bay of Biscay, almost all pre-Eocene AfricaEurope convergence in the Iberian segment was accommodated in the Pyrenees, and Afr ...
... the Pyrenees [e.g., Dewey et al., 1989; Rosenbaum et al., 2002b; Sibuet et al., 2004; Vissers and Meijer, 2012a, 2012b]. Following marine magnetic anomaly constraints of the Bay of Biscay, almost all pre-Eocene AfricaEurope convergence in the Iberian segment was accommodated in the Pyrenees, and Afr ...
- ERA - University of Alberta
... observations of an abnormally thin lithosphere beneath some regions and evidence for detached lithospheric materials at 100-200 km depth. ...
... observations of an abnormally thin lithosphere beneath some regions and evidence for detached lithospheric materials at 100-200 km depth. ...
Alkalic magmas generated by partial melting of
... become similar in composition to partial melts of peridotite or hybridized peridotite. Lundstrom et al. (2000) argued that such reactions promote formation of dunite channels. If pyroxenite bodies have relatively large spatial dimensions, their partial melts could segregate into conduits that allow ...
... become similar in composition to partial melts of peridotite or hybridized peridotite. Lundstrom et al. (2000) argued that such reactions promote formation of dunite channels. If pyroxenite bodies have relatively large spatial dimensions, their partial melts could segregate into conduits that allow ...
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... isotopic compositions indicating isolation from the asthenosphere for a long time. 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 juveni ...
... isotopic compositions indicating isolation from the asthenosphere for a long time. 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 juveni ...
State of lithosphere beneath Tien Shan from petrology and electrical
... active structures of the Tarim Plate (on the south) and the stable Kazakh Platform (on the north). [5] The geodynamic history related to the structure of the investigated Tarim‐Tien Shan junction zone may be divided into four main periods (Figure 1b). During the first period, corresponding to C1–2 ( ...
... active structures of the Tarim Plate (on the south) and the stable Kazakh Platform (on the north). [5] The geodynamic history related to the structure of the investigated Tarim‐Tien Shan junction zone may be divided into four main periods (Figure 1b). During the first period, corresponding to C1–2 ( ...
Crystal preferred orientation of an amphibole experimentally
... Previous experimental studies of amphibolite primarily focused on the mechanical behaviour of amphibole under uniaxial compression. Water weakening of amphibolite was observed at a temperature of 800 °C and confining pressures of 0.5–2 GPa due to the dehydration reaction of hornblende21–23. The exper ...
... Previous experimental studies of amphibolite primarily focused on the mechanical behaviour of amphibole under uniaxial compression. Water weakening of amphibolite was observed at a temperature of 800 °C and confining pressures of 0.5–2 GPa due to the dehydration reaction of hornblende21–23. The exper ...
Rifting, Seafloor Spreading, and Extensional Tectonics
... volcanics. A preserved inactive rift can also be called an unsuccessful rift, in that its existence reflects the occurrence of a rifting event that stopped before it succeeded in splitting a continent in two. Unsuccessful rifts that cut into cratonic areas of continents, at a high angle to the conti ...
... volcanics. A preserved inactive rift can also be called an unsuccessful rift, in that its existence reflects the occurrence of a rifting event that stopped before it succeeded in splitting a continent in two. Unsuccessful rifts that cut into cratonic areas of continents, at a high angle to the conti ...
7.08 Mantle Downwellings and the Fate of Subducting Slabs
... within subduction zones. Not only do subducted slabs change dip along the length of an arc, studies increasingly recognize slab tears, slab windows, and other forms of slab deformation. While such complexity was noted in some of the earliest subduction zone studies (e.g., Isacks and Molnar, 1971), m ...
... within subduction zones. Not only do subducted slabs change dip along the length of an arc, studies increasingly recognize slab tears, slab windows, and other forms of slab deformation. While such complexity was noted in some of the earliest subduction zone studies (e.g., Isacks and Molnar, 1971), m ...
Oxygen-isotope and trace element constraints on the origins of silica
... We tested this hypothesis by analyzing the oxygen isotope compositions of these inclusions with an ion microprobe. The melt inclusions from Batan xenoliths have d 18OVSMOW values of 6.45 ± 0.51%. These values are consistent with the melts having been in oxygen isotope exchange equilibrium with avera ...
... We tested this hypothesis by analyzing the oxygen isotope compositions of these inclusions with an ion microprobe. The melt inclusions from Batan xenoliths have d 18OVSMOW values of 6.45 ± 0.51%. These values are consistent with the melts having been in oxygen isotope exchange equilibrium with avera ...
alps vs apennines - Dipartimento di Scienze della Terra
... (BOCCALETTI et alii, 1990). The Alps grew laterally and vertically expanding first the retrobelt and then the forebelt during the subduction stage, eventually involving the footwall continental lithosphere during collision, and amplifying the elevation and the lateral expansion of both sides (Figs 2 ...
... (BOCCALETTI et alii, 1990). The Alps grew laterally and vertically expanding first the retrobelt and then the forebelt during the subduction stage, eventually involving the footwall continental lithosphere during collision, and amplifying the elevation and the lateral expansion of both sides (Figs 2 ...
Thesis pdf
... transects. In the northern profile (northern Zagros), the LAB rises sharply below the Sanandaj Sirjan Zone in a narrow region of ~90 km, whereas in the southern profile (central Zagros), rising occurs in wider region, from the Zagros Fold-and-Thrust Belt to the Sanandaj Sirjan Zone. The best fit of ...
... transects. In the northern profile (northern Zagros), the LAB rises sharply below the Sanandaj Sirjan Zone in a narrow region of ~90 km, whereas in the southern profile (central Zagros), rising occurs in wider region, from the Zagros Fold-and-Thrust Belt to the Sanandaj Sirjan Zone. The best fit of ...
Paper Oman, 2001
... A 2-D physical and finite-element numerical modelling of arc continent collision was performed to study the deformation and failure of the overriding lithosphere. The experimental technique allowed us to model the whole subduction/collision process from oceanic subduction to deep subduction of the c ...
... A 2-D physical and finite-element numerical modelling of arc continent collision was performed to study the deformation and failure of the overriding lithosphere. The experimental technique allowed us to model the whole subduction/collision process from oceanic subduction to deep subduction of the c ...
Antigorite Peridotite, Metaserpentinite, and other
... The NVF is located in the interior of the Colorado Plateau, which is a relatively stable block of continental lithosphere (Fig. 1). Laramide-related deformation began in the plateau interior between 80 and 75 Ma and ended at about 36 Ma (Cather, 2004). Regions to the west, south, and east of the pla ...
... The NVF is located in the interior of the Colorado Plateau, which is a relatively stable block of continental lithosphere (Fig. 1). Laramide-related deformation began in the plateau interior between 80 and 75 Ma and ended at about 36 Ma (Cather, 2004). Regions to the west, south, and east of the pla ...
Full text PDF - Geochemical Perspectives
... working with my own generation of mantle geochemists, many of them students of these founders. I dare not list their names for fear of leaving some out, but their work is cited in this narrative. I was not present for the birth of mantle and isotope geochemistry, so there is a backstory and a histor ...
... working with my own generation of mantle geochemists, many of them students of these founders. I dare not list their names for fear of leaving some out, but their work is cited in this narrative. I was not present for the birth of mantle and isotope geochemistry, so there is a backstory and a histor ...
The Volume and Composition of Melt Generated
... earth's surface. Adiabatic upwelling leaves TP unchanged. TP only changes when the entropy of the material changes. Though there is a simple relationship between the change in entropy AS and the associated change in potential temperature, the concept of entropy is less familiar than that of temperat ...
... earth's surface. Adiabatic upwelling leaves TP unchanged. TP only changes when the entropy of the material changes. Though there is a simple relationship between the change in entropy AS and the associated change in potential temperature, the concept of entropy is less familiar than that of temperat ...
lithosphere 2006 - Helsingin yliopisto
... T. Stålfors, C. Ehlers and A. Johnson. The granite-migmatite zone of southern Finland – A history of structural control and intrusions I.T. Kukkonen and L.S. Lauri. Modelling the thermal evolution of a Precambrian orogen: high heat production migmatitic granites of southern Finland L.S. Lauri, M. Cu ...
... T. Stålfors, C. Ehlers and A. Johnson. The granite-migmatite zone of southern Finland – A history of structural control and intrusions I.T. Kukkonen and L.S. Lauri. Modelling the thermal evolution of a Precambrian orogen: high heat production migmatitic granites of southern Finland L.S. Lauri, M. Cu ...
Back-arc strain in subduction zones: Statistical observations versus
... [1] Recent statistical analysis by Lallemand et al. (2008) of subduction zone parameters revealed that the back-arc deformation mode depends on the combination between the subducting (vsub) and upper (vup) plate velocities. No significant strain is recorded in the arc area if plate kinematics verifi ...
... [1] Recent statistical analysis by Lallemand et al. (2008) of subduction zone parameters revealed that the back-arc deformation mode depends on the combination between the subducting (vsub) and upper (vup) plate velocities. No significant strain is recorded in the arc area if plate kinematics verifi ...
Volledig proefschrift
... During its 4.6 billion year history, the Earth has shown continuous activity to loose its heat. The heat budget of the Earth determines the vigor of mantle convection, the amount of mantle plume activity, and the type of the tectonic regime. The main heat sources in this system are primordial heat, ...
... During its 4.6 billion year history, the Earth has shown continuous activity to loose its heat. The heat budget of the Earth determines the vigor of mantle convection, the amount of mantle plume activity, and the type of the tectonic regime. The main heat sources in this system are primordial heat, ...
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... adakite-like rhyodacites (Jamaican-type adakites: JTA) from Jamaica are shown to be geochemically similar to the Eoarchaean TTGs. In contrast to newly discovered JTA-like rocks (Ryozen low Sr/Y) in Japan, new trace element and Nd–Hf radiogenic isotope data in this study confirm that the Jamaican JTA ...
... adakite-like rhyodacites (Jamaican-type adakites: JTA) from Jamaica are shown to be geochemically similar to the Eoarchaean TTGs. In contrast to newly discovered JTA-like rocks (Ryozen low Sr/Y) in Japan, new trace element and Nd–Hf radiogenic isotope data in this study confirm that the Jamaican JTA ...
Is the rate of supercontinent assembly changing with time?
... We still have many questions regarding the supercontinent cycle, such as when it began, has continental crust grown in volume with time, and has the period of the cycle been constant or has it changed with time. The timescale of assembly and dispersal of supercontinents is still not well constrained ...
... We still have many questions regarding the supercontinent cycle, such as when it began, has continental crust grown in volume with time, and has the period of the cycle been constant or has it changed with time. The timescale of assembly and dispersal of supercontinents is still not well constrained ...
Global geochemical variation of mid-ocean ridge basalts - UiO
... 1.1. A brief introduction to MORB and mantle geochemistry The mid ocean ridges (MORs) are the Earth’s longest mountain chain and are present at all divergent plate boundaries. At the MORs the lithosphere that gets recycled into the mantle at the subduction zones, their plate tectonical counterparts, ...
... 1.1. A brief introduction to MORB and mantle geochemistry The mid ocean ridges (MORs) are the Earth’s longest mountain chain and are present at all divergent plate boundaries. At the MORs the lithosphere that gets recycled into the mantle at the subduction zones, their plate tectonical counterparts, ...
UHP metamorphism in garnet peridotite, Cuaba unit, Rio San Juan
... Four attributes suggest low-P/T (UHT) conditions: (1) Sequence of mineral assemblages, (2) nature of associated rocks, (3) Cr-in-clinopyroxene, Mg2Si2O6-in-clinopyroxene thermobarometry (>1.8 Gpa, >900 ˚C), and (4) tectonic setting. However, the thermobarometry is questionable because of low Cr in c ...
... Four attributes suggest low-P/T (UHT) conditions: (1) Sequence of mineral assemblages, (2) nature of associated rocks, (3) Cr-in-clinopyroxene, Mg2Si2O6-in-clinopyroxene thermobarometry (>1.8 Gpa, >900 ˚C), and (4) tectonic setting. However, the thermobarometry is questionable because of low Cr in c ...
subduction zones
... uses seismic velocity information from many ray paths, crisscrossing Earth between various points near Earth’s surface and reaching different depths in its interior, to produce a three-dimensional (3-D) model of relative velocity. Regions of anomalously fast mantle corre- ...
... uses seismic velocity information from many ray paths, crisscrossing Earth between various points near Earth’s surface and reaching different depths in its interior, to produce a three-dimensional (3-D) model of relative velocity. Regions of anomalously fast mantle corre- ...
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... uses seismic velocity information from many ray paths, crisscrossing Earth between various points near Earth’s surface and reaching different depths in its interior, to produce a three-dimensional (3-D) model of relative velocity. Regions of anomalously fast mantle corre- ...
... uses seismic velocity information from many ray paths, crisscrossing Earth between various points near Earth’s surface and reaching different depths in its interior, to produce a three-dimensional (3-D) model of relative velocity. Regions of anomalously fast mantle corre- ...
Post-glacial rebound
Post-glacial rebound (sometimes called continental rebound) is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period, through a process known as isostatic depression. Post-glacial rebound and isostatic depression are different parts of a process known as either glacial isostasy, glacial isostatic adjustment, or glacioisostasy. Glacioisostasy is the solid Earth deformation associated with changes in ice mass distribution. The most obvious and direct affects of post-glacial rebound are readily apparent in northern Europe (especially Scotland, Estonia, Latvia, Fennoscandia, and northern Denmark), Siberia, Canada, the Great Lakes of Canada and the United States, the coastal region of the US state of Maine, parts of Patagonia, and Antarctica. However, through processes known as ocean siphoning and continental levering, the effects of post-glacial rebound on sea-level are felt globally far from the locations of current and former ice sheets.