thrust systems - The Web site cannot be found
... orogeny. Erosion levelled ancient orogens to flatlands in the relatively inactive interior of continents. In addition, the structurally challenging parts of recent and growing orogens may not lie in the visible mountains; instead, they may be 10 or even 100 km below the Earth’s surface. The geometri ...
... orogeny. Erosion levelled ancient orogens to flatlands in the relatively inactive interior of continents. In addition, the structurally challenging parts of recent and growing orogens may not lie in the visible mountains; instead, they may be 10 or even 100 km below the Earth’s surface. The geometri ...
47. the ocean/continent transition beneath the iberia abyssal plain
... The first quantitatively rigorous fit of North America to Europe was performed by Bullard et al. (1965). They confirmed that, once the Bay of Biscay itself had been closed by a clockwise rotation of Iberia against Europe, the southeast Grand Banks margin could be matched with the west Iberia Margin. ...
... The first quantitatively rigorous fit of North America to Europe was performed by Bullard et al. (1965). They confirmed that, once the Bay of Biscay itself had been closed by a clockwise rotation of Iberia against Europe, the southeast Grand Banks margin could be matched with the west Iberia Margin. ...
AbdolnaserFazlnia-Word offic file
... overlying mantle wedge or both. Evidence from active subduction systems suggests that slab melting is a rare process restricted to hot and young slabs (Sigmarsson et al., 1998; Schaltegger et al., 2002; Dhuime et al., 2009; Petterson, 2010; Guarino et al., 2011). Melts are commonly formed in the ove ...
... overlying mantle wedge or both. Evidence from active subduction systems suggests that slab melting is a rare process restricted to hot and young slabs (Sigmarsson et al., 1998; Schaltegger et al., 2002; Dhuime et al., 2009; Petterson, 2010; Guarino et al., 2011). Melts are commonly formed in the ove ...
vi. north moluccas
... Carlile, J.C., G.R. Davey, I. Kadir, R.P. Langmead & W.J. Rafferty (1998)- Discovery and exploration of the Gosowong epithermal gold deposit, Halmahera, Indonesia. J. Geochemical Exploration 60, 3, p. 207-227. (Gosowong epithermal gold deposit low-sulphidation epithermal quartz vein in Halmahera Ne ...
... Carlile, J.C., G.R. Davey, I. Kadir, R.P. Langmead & W.J. Rafferty (1998)- Discovery and exploration of the Gosowong epithermal gold deposit, Halmahera, Indonesia. J. Geochemical Exploration 60, 3, p. 207-227. (Gosowong epithermal gold deposit low-sulphidation epithermal quartz vein in Halmahera Ne ...
Moho and magmatic underplating
... low average density of the crystalline basement (Arndt, this volume; Hawkesworth et al., this volume). The continental crust is subsequently affected by a variety of tectonic, erosional, depositional and metamorphic processes, which define the evolution of individual regions. Clearly, plate boundary ...
... low average density of the crystalline basement (Arndt, this volume; Hawkesworth et al., this volume). The continental crust is subsequently affected by a variety of tectonic, erosional, depositional and metamorphic processes, which define the evolution of individual regions. Clearly, plate boundary ...
univERsity oF copEnhAGEn
... low average density of the crystalline basement (Arndt, this volume; Hawkesworth et al., this volume). The continental crust is subsequently affected by a variety of tectonic, erosional, depositional and metamorphic processes, which define the evolution of individual regions. Clearly, plate boundary ...
... low average density of the crystalline basement (Arndt, this volume; Hawkesworth et al., this volume). The continental crust is subsequently affected by a variety of tectonic, erosional, depositional and metamorphic processes, which define the evolution of individual regions. Clearly, plate boundary ...
evolution of the north american cordillera
... Key Words continental margin, crustal genesis, geologic history, orogen, tectonics ■ Abstract The Cordilleran orogen of western North America is a segment of the Circum-Pacific orogenic belt where subduction of oceanic lithosphere has been underway along a great circle of the globe since breakup of ...
... Key Words continental margin, crustal genesis, geologic history, orogen, tectonics ■ Abstract The Cordilleran orogen of western North America is a segment of the Circum-Pacific orogenic belt where subduction of oceanic lithosphere has been underway along a great circle of the globe since breakup of ...
EVOLUTION OF THE NORTH AMERICAN CORDILLERA William R
... Key Words continental margin, crustal genesis, geologic history, orogen, tectonics ■ Abstract The Cordilleran orogen of western North America is a segment of the Circum-Pacific orogenic belt where subduction of oceanic lithosphere has been underway along a great circle of the globe since breakup of ...
... Key Words continental margin, crustal genesis, geologic history, orogen, tectonics ■ Abstract The Cordilleran orogen of western North America is a segment of the Circum-Pacific orogenic belt where subduction of oceanic lithosphere has been underway along a great circle of the globe since breakup of ...
1 Bathymetry of the Pacific Plate and its Implications for Thermal
... (Figure 3a). If the topography is examined region by region, then it is clear that these features are largely controlled by the central region. For the northern region, the “flattening” does not start until ~85 Ma, and the standard deviation is uniformly small (generally <~400 m) also until ~85 Ma w ...
... (Figure 3a). If the topography is examined region by region, then it is clear that these features are largely controlled by the central region. For the northern region, the “flattening” does not start until ~85 Ma, and the standard deviation is uniformly small (generally <~400 m) also until ~85 Ma w ...
Geophysical Journal International - E
... (down to 19 km) and in the Guadalquivir basin where the thinning at the Iberian paleomargin could be still preserved. In the cross-sections, we see a strong change between the eastern Betics, where the Iberian crust underthrusts and couples to the Alboran crust, and the western Betics, where the und ...
... (down to 19 km) and in the Guadalquivir basin where the thinning at the Iberian paleomargin could be still preserved. In the cross-sections, we see a strong change between the eastern Betics, where the Iberian crust underthrusts and couples to the Alboran crust, and the western Betics, where the und ...
FOSI BeritaSedimentologi BS 23 March2012
... 1996). Further, we suggest that the Triassic section was scraped off the downgoing slab as an accretionary prism and emplaced onto the adjacent margin. Importantly, this implies that the underlying oceanic crust was Permian or older. Snyder et al (1996) show subsea contours in depth on the downgoing ...
... 1996). Further, we suggest that the Triassic section was scraped off the downgoing slab as an accretionary prism and emplaced onto the adjacent margin. Importantly, this implies that the underlying oceanic crust was Permian or older. Snyder et al (1996) show subsea contours in depth on the downgoing ...
- Wiley Online Library
... weaker mechanisms must be included. Similarly, it has become standard to include phase transition and realistic composition in the crust [e.g., Yamato et al., 2007; Gerya et al., 2008] to study the dynamic of active margins. However, the effect of petrological composition, and especially the extent ...
... weaker mechanisms must be included. Similarly, it has become standard to include phase transition and realistic composition in the crust [e.g., Yamato et al., 2007; Gerya et al., 2008] to study the dynamic of active margins. However, the effect of petrological composition, and especially the extent ...
Physics and Chemistry of Deep Continental Crust
... suggest that lower crustal recycling occurs, finding direct evidence for such a process is difficult because the hypothetical mafic component is generally missing. It is thus important to understand the physics of lower crustal recycling. What conditions are necessary for recycling so that we can de ...
... suggest that lower crustal recycling occurs, finding direct evidence for such a process is difficult because the hypothetical mafic component is generally missing. It is thus important to understand the physics of lower crustal recycling. What conditions are necessary for recycling so that we can de ...
Weakening of the subduction interface and its effects on surface
... Metamorphic reactions and water flow are not included except as the proposed mechanism for altering interface properties. The complex, nonlinear feedbacks between thermal, hydrological, mineralogical, and mechanical processes are only qualitatively discussed. These simplifications are technically ne ...
... Metamorphic reactions and water flow are not included except as the proposed mechanism for altering interface properties. The complex, nonlinear feedbacks between thermal, hydrological, mineralogical, and mechanical processes are only qualitatively discussed. These simplifications are technically ne ...
Sabzevar Ophiolite, NE Iran - The University of Texas at Dallas
... The poorly known Sabzevar–Torbat-e-Heydarieh ophiolite belt (STOB) covers a large region in NE Iran, over 400 km E-W and almost 200 km N-S. The Sabzevar mantle sequence includes harzburgite, lherzolite, dunite and chromitite. Spinel Cr# (100Cr/(Cr + Al)) in harzburgites and lherzolites ranges from 4 ...
... The poorly known Sabzevar–Torbat-e-Heydarieh ophiolite belt (STOB) covers a large region in NE Iran, over 400 km E-W and almost 200 km N-S. The Sabzevar mantle sequence includes harzburgite, lherzolite, dunite and chromitite. Spinel Cr# (100Cr/(Cr + Al)) in harzburgites and lherzolites ranges from 4 ...
Thermal and petrophysical characterization of the lithospheric
... In the Valencia Trough Basin extension lasted from Late Oligocene to Langhian period, whereas the opening of the Algerian Basin began later (latest Early Miocene–Middle Miocene) and ended during the Tortonian when remnants of the southern Iberia continental margin (the Kabylies) accreted with the Af ...
... In the Valencia Trough Basin extension lasted from Late Oligocene to Langhian period, whereas the opening of the Algerian Basin began later (latest Early Miocene–Middle Miocene) and ended during the Tortonian when remnants of the southern Iberia continental margin (the Kabylies) accreted with the Af ...
Alignment between seafloor spreading directions and absolute plate
... with plate spreading direction. Low-velocity fingers imaged at the base of the oceanic asthenosphere have been interpreted as regions of channelized mantle flow aligned with present-day APM [French et al., 2013]. These observations provide strong evidence for a relationship between spreading direction ...
... with plate spreading direction. Low-velocity fingers imaged at the base of the oceanic asthenosphere have been interpreted as regions of channelized mantle flow aligned with present-day APM [French et al., 2013]. These observations provide strong evidence for a relationship between spreading direction ...
Plate Tectonics - The Open University
... supercontinent that he named Pangaea, meaning 'all Earth'. He drew maps showing how the continents have since moved to today's positions. He proposed that Pangaea began to break apart just after the beginning of the Mesozoic Era, about 200 Ma ago, and that the continents then slowly drifted into the ...
... supercontinent that he named Pangaea, meaning 'all Earth'. He drew maps showing how the continents have since moved to today's positions. He proposed that Pangaea began to break apart just after the beginning of the Mesozoic Era, about 200 Ma ago, and that the continents then slowly drifted into the ...
Synthesis of Results From the CD-ROM Experiment
... complex geometry related both to the N-S Rio Grande rift and the NE-trending Colorado mineral belt. But low velocity mantle is seen in the southern CD-ROM line (Plate 3) that projects towards the surface trace of the Colorado mineral belt and dips to the south to great depth (> 200 km). A similar na ...
... complex geometry related both to the N-S Rio Grande rift and the NE-trending Colorado mineral belt. But low velocity mantle is seen in the southern CD-ROM line (Plate 3) that projects towards the surface trace of the Colorado mineral belt and dips to the south to great depth (> 200 km). A similar na ...
Shape and origin of the East-Alpine slab constrained by the
... During the last two decades teleseismic studies yielded valuable information on the structure of the upper mantle below the Alpine–Mediterranean area. Subducted oceanic lithosphere forms a broad anomaly resting on but not penetrating the 670 km discontinuity. More shallow slabs imaged below the Alpi ...
... During the last two decades teleseismic studies yielded valuable information on the structure of the upper mantle below the Alpine–Mediterranean area. Subducted oceanic lithosphere forms a broad anomaly resting on but not penetrating the 670 km discontinuity. More shallow slabs imaged below the Alpi ...
Subduction erosion modes: Comparing finite
... have been estimated in the central Andes due to subduction erosion (Kukowski and Oncken, 2006). Elsewhere, higher rates of ca. 10 km Ma− 1 have been associated with topographic asperities on the lower plate (e.g. Clift et al., 2003). Possible mechanisms for this mode of subduction erosion include du ...
... have been estimated in the central Andes due to subduction erosion (Kukowski and Oncken, 2006). Elsewhere, higher rates of ca. 10 km Ma− 1 have been associated with topographic asperities on the lower plate (e.g. Clift et al., 2003). Possible mechanisms for this mode of subduction erosion include du ...
Introduction - Beck-Shop
... primitive crust most probably was mafic, and formed on top of a previously convecting magma ocean of uncertain depth (Boyet et al., 2003). However, no outcrop evidence of this earliest primitive crust is known to have survived, probably due to the intense meteor bombardment that affected Earth betwe ...
... primitive crust most probably was mafic, and formed on top of a previously convecting magma ocean of uncertain depth (Boyet et al., 2003). However, no outcrop evidence of this earliest primitive crust is known to have survived, probably due to the intense meteor bombardment that affected Earth betwe ...
3.20 Trace Element and Isotopic Fluxes
... is possible to evaluate chemical changes in subducting oceanic crust and overlying sediments (see Chapter 3.09, for discussion of UHP metamorphic geochemistry of continental lithologies in collisional orogens such as Dabieshan-Su-Lu Belt and Kokchetav Massif). Emphasis is placed on elucidating conne ...
... is possible to evaluate chemical changes in subducting oceanic crust and overlying sediments (see Chapter 3.09, for discussion of UHP metamorphic geochemistry of continental lithologies in collisional orogens such as Dabieshan-Su-Lu Belt and Kokchetav Massif). Emphasis is placed on elucidating conne ...
TROPICS Continent-Building in Costa Rica
... have started in the relatively recent past, and appear to be continuing to the present-day. Igneous rocks older than about 30 Ma have unremarkable chemistries typical of oceanic basalts and intra-oceanic arcs. In contrast, younger (<10 ma) rocks are significantly enriched in Si, alkalis and light ra ...
... have started in the relatively recent past, and appear to be continuing to the present-day. Igneous rocks older than about 30 Ma have unremarkable chemistries typical of oceanic basalts and intra-oceanic arcs. In contrast, younger (<10 ma) rocks are significantly enriched in Si, alkalis and light ra ...
Differentiation of the continental crust by relamination
... 2003a), loss of these rocks still yielded a mafic arc crust very different from continental crust (DeBari and Sleep, 1991; Greene et al., 2006). This is so because garnet-free mafic rocks that are either density-stable or too viscous to founder remain in the cold, upper and middle crust. Whereas found ...
... 2003a), loss of these rocks still yielded a mafic arc crust very different from continental crust (DeBari and Sleep, 1991; Greene et al., 2006). This is so because garnet-free mafic rocks that are either density-stable or too viscous to founder remain in the cold, upper and middle crust. Whereas found ...
Izu-Bonin-Mariana Arc
The Izu-Bonin-Mariana (IBM) arc system is an outstanding example of a plate tectonic convergent boundary. IBM extends over 2800 km south from Tokyo, Japan, to beyond Guam, and includes the Izu Islands, Bonin Islands, and Mariana Islands; much more of the IBM arc system is submerged below sealevel. The IBM arc system lies along the eastern margin of the Philippine Sea Plate in the Western Pacific Ocean. It is most famous for being the site of the deepest gash in Earth's solid surface, the Challenger Deep in the Mariana Trench. The IBM arc system formed as a result of subduction of the western Pacific plate. The IBM arc system now subducts mid-Jurassic to Early Cretaceous lithosphere, with younger lithosphere in the north and older lithosphere in the south, including the oldest (~170 million years old, or Ma) oceanic crust. Subduction rates vary from ~2 cm (1 inch) per year in the south to 6 cm (~2.5 inches) in the north. The volcanic islands that comprise these island arcs are thought to have been formed from the release of volatiles (steam from trapped water, and other gases) being released from the subducted plate, as it reached sufficient depth for the temperature to cause release of these materials. The associated trenches are formed as the oldest (most western) part of the Pacific plate crust increases in density with age, and because of this process finally reaches its lowest point just as it subducts under the crust to the west of it.The IBM arc system is an excellent example of an intra-oceanic convergent margin (IOCM). IOCMs are built on oceanic crust and contrast fundamentally with island arc built on continental crust, such as Japan or the Andes. Because IOCM crust is thinner, denser, and more refractory than that beneath Andean-type margins, study of IOCM melts and fluids allows more confident assessment of mantle-to-crust fluxes and processes than is possible for Andean-type convergent margins. Because IOCMs are far removed from continents they are not affected by the large volume of alluvial and glacial sediments. The consequent thin sedimentary cover makes it much easier to study arc infrastructure and determine the mass and composition of subducted sediments. Active hydrothermal systems found on the submarine parts of IOCMs give us a chance to study how many of earth's important ore deposits formed.