exploringthe Submarine ring of fire
... movie. But, we had the good fortune to observe these and other previously unseen phenomena between 2004 and 2006 during a series of expeditions to the Mariana arc in the western Pacific. We describe here several of the most interesting sites, along with their geologic and oceanographic contexts. Som ...
... movie. But, we had the good fortune to observe these and other previously unseen phenomena between 2004 and 2006 during a series of expeditions to the Mariana arc in the western Pacific. We describe here several of the most interesting sites, along with their geologic and oceanographic contexts. Som ...
The significance of sheeted dike complexes in ophiolites
... Oceanic lithosphere is produced at different rates along modern spreading centers, leading to different structural architectures (Karson, 1998). Fast-spreading mid-ocean ridges are generally characterized by a voluminous magma supply and have well-defined convex axial highs, whereas slow-spreading r ...
... Oceanic lithosphere is produced at different rates along modern spreading centers, leading to different structural architectures (Karson, 1998). Fast-spreading mid-ocean ridges are generally characterized by a voluminous magma supply and have well-defined convex axial highs, whereas slow-spreading r ...
Research Focus: Crust formation in the western United
... resolution of the controversy. For example, inherited zircons in plutonic and volcanic rocks simply indicate that there was “communication” between older continental crust and the locus of magma production. The presence of inherited zircons does not require that older crust exists either in the area ...
... resolution of the controversy. For example, inherited zircons in plutonic and volcanic rocks simply indicate that there was “communication” between older continental crust and the locus of magma production. The presence of inherited zircons does not require that older crust exists either in the area ...
The Race Is On with Seafloor Spreading!
... determined. 5. This area represents a fracture zone, an extension of a transform fault, which offsets the spreading zones. 6. The average spreading rates are greater for the Pacific-Nazca plates than the Cocos-Nazca plates. This area represents an area of fast seafloor spreading. 7. Subduction is ...
... determined. 5. This area represents a fracture zone, an extension of a transform fault, which offsets the spreading zones. 6. The average spreading rates are greater for the Pacific-Nazca plates than the Cocos-Nazca plates. This area represents an area of fast seafloor spreading. 7. Subduction is ...
The chemical composition of subducting sediment and its
... Subducted sediments play an important role in arc magmatism and crust–mantle recycling. Models of continental growth, continental composition, convergent margin magmatism and mantle heterogeneity all require a better understanding of the mass and chemical fluxes associated with subducting sediments. ...
... Subducted sediments play an important role in arc magmatism and crust–mantle recycling. Models of continental growth, continental composition, convergent margin magmatism and mantle heterogeneity all require a better understanding of the mass and chemical fluxes associated with subducting sediments. ...
On the shallow origin of hotspots and the westward drift of the
... movement of the lithosphere relative to the mantle should then be taken into account in an “absolute” plate motion analysis, and the NNR should be abandoned. The absolute reference frame is quite a controversial issue. Typically, the absolute reference frame is considered to be that of the hotspots. ...
... movement of the lithosphere relative to the mantle should then be taken into account in an “absolute” plate motion analysis, and the NNR should be abandoned. The absolute reference frame is quite a controversial issue. Typically, the absolute reference frame is considered to be that of the hotspots. ...
The link between the Moho depth of the NE Atlantic margin and
... continent, the magnetic field is only of limited use to analyze the deep structure of the margin, while it clearly helps to study crustal domains and top basement. Gravity and GOCE satellite data The thermal gradient between the oceanic and continental plate is also observable as a long wavelength t ...
... continent, the magnetic field is only of limited use to analyze the deep structure of the margin, while it clearly helps to study crustal domains and top basement. Gravity and GOCE satellite data The thermal gradient between the oceanic and continental plate is also observable as a long wavelength t ...
Partial delamination of continental mantle lithosphere, uplift
... Geological and Environmental Sciences, Stanford University, Stanford, CA 94305-2115, USA Received 21 January 2000; revised 30 May 2000; accepted 16 June 2000 ...
... Geological and Environmental Sciences, Stanford University, Stanford, CA 94305-2115, USA Received 21 January 2000; revised 30 May 2000; accepted 16 June 2000 ...
Mantle convection in the Middle East_ Reconciling Afar upwelling
... proposed that mantle drag related to a large-scale convection cell could efficiently pull continental plates toward collisional zones, thus favouring indentation (Alvarez, 2010; Becker and Faccenna, 2011). This model also agrees with previous studies which suggested that Arabia is dynamically tilted ...
... proposed that mantle drag related to a large-scale convection cell could efficiently pull continental plates toward collisional zones, thus favouring indentation (Alvarez, 2010; Becker and Faccenna, 2011). This model also agrees with previous studies which suggested that Arabia is dynamically tilted ...
What drives microplate motion and deformation in the northeastern
... Bahamas Platform [Pardo, 1975]. This suggests that the present collision is “soft”, i.e., that the collision forces on the Caribbean plate and vice versa are relatively small and that the Bahamas Platform alone is unlikely to explain the observed fragmentation of the northeastern Caribbean plate bou ...
... Bahamas Platform [Pardo, 1975]. This suggests that the present collision is “soft”, i.e., that the collision forces on the Caribbean plate and vice versa are relatively small and that the Bahamas Platform alone is unlikely to explain the observed fragmentation of the northeastern Caribbean plate bou ...
Plate Tectonics
... The movement of plates on Earth causes forces that build up energy in rocks. The release of this energy can produce vibrations in Earth that you know as earthquakes. Earthquakes occur every day. Many of them are too small to be felt by humans, but each event tells scientists something more about the ...
... The movement of plates on Earth causes forces that build up energy in rocks. The release of this energy can produce vibrations in Earth that you know as earthquakes. Earthquakes occur every day. Many of them are too small to be felt by humans, but each event tells scientists something more about the ...
Bivergent thrust wedges surrounding oceanic island arcs: Insight
... of longitude 68.5°W, these faults curve northward, and between longitude 68°W and 67.7°W, they terminate at the thrust front. Similar normal faults have been observed on many subducting plates to a distance of 50–60 km oceanward of the trench, and they are interpreted to be a deformational response ...
... of longitude 68.5°W, these faults curve northward, and between longitude 68°W and 67.7°W, they terminate at the thrust front. Similar normal faults have been observed on many subducting plates to a distance of 50–60 km oceanward of the trench, and they are interpreted to be a deformational response ...
Alteration of stress field brought about by the occurrence of... M 9.0) w
... positive CFF near the down-dip end of the fault zone. Beyond the depth of 60 km, the still large positive CFF does not directly indicate a high probability for future interplate earthquakes because the slip over the area is considered to be aseismic. The area near the up-dip end of the fault zone, ...
... positive CFF near the down-dip end of the fault zone. Beyond the depth of 60 km, the still large positive CFF does not directly indicate a high probability for future interplate earthquakes because the slip over the area is considered to be aseismic. The area near the up-dip end of the fault zone, ...
The global range of subduction zone thermal structures from
... plate from large-scale flow of asthenospheric mantle to depths of ∼80 km (e.g. Wada and Wang, 2009). The other three Syracuse et al. (2010) models result in similar or colder P–T estimates. The range of P–T conditions predicted for the uppermost part of the basaltic oceanic crust of the 56 subduction ...
... plate from large-scale flow of asthenospheric mantle to depths of ∼80 km (e.g. Wada and Wang, 2009). The other three Syracuse et al. (2010) models result in similar or colder P–T estimates. The range of P–T conditions predicted for the uppermost part of the basaltic oceanic crust of the 56 subduction ...
Registered talks and posters, OMARC conference
... Solid products of deep-sea mud volcanic emissions as an insight into sedimentary successions of ocean margins Mud volcanism and fluid emission in Eastern Mediterranean neotectonic zones HYACINTH – bringing pressure coring to mainstream oceanographic research Plutonium isotope ratios in shelf sedimen ...
... Solid products of deep-sea mud volcanic emissions as an insight into sedimentary successions of ocean margins Mud volcanism and fluid emission in Eastern Mediterranean neotectonic zones HYACINTH – bringing pressure coring to mainstream oceanographic research Plutonium isotope ratios in shelf sedimen ...
Lithosphere and Asthenosphere
... 3. How do the lithosphere and asthenosphere differ? 4. If the lithosphere is resting on the asthenosphere and you put a lot of weight on the lithosphere, say ice in a glacier, how would the lithosphere respond? ...
... 3. How do the lithosphere and asthenosphere differ? 4. If the lithosphere is resting on the asthenosphere and you put a lot of weight on the lithosphere, say ice in a glacier, how would the lithosphere respond? ...
Resistivity Cross Section Through the Juan de Fuca Subduction
... off-scrapedor lose most of their interstitial water before being carriedmore than ten or so kilometersdown the trench. In the oceanicuppermanfieof the Juande Fucaplate, moderatelylow resistivitiesfrom about 35-215 km depth (nominal) presumablyreflect up to several percent partial melt attending regi ...
... off-scrapedor lose most of their interstitial water before being carriedmore than ten or so kilometersdown the trench. In the oceanicuppermanfieof the Juande Fucaplate, moderatelylow resistivitiesfrom about 35-215 km depth (nominal) presumablyreflect up to several percent partial melt attending regi ...
Plate Tectonics Conceptest
... Evidence from the Seafloor In the decades following Wegener’s research, key observations about the seafloor contributed to a new understanding of Earth processes − Seafloor topography − Age of the seafloor ...
... Evidence from the Seafloor In the decades following Wegener’s research, key observations about the seafloor contributed to a new understanding of Earth processes − Seafloor topography − Age of the seafloor ...
12.710 – Problem Set 4 solutions 1. What is “the geothermal
... temperature at the surface of the Earth; the core-mantle boundary (experiments and seismic velocity profiles); the upper mantle-lower mantle boundary and the transition zone (also experiments and velocity profiles), the crust-mantle boundary, and the base of the lithosphere. Because continental crus ...
... temperature at the surface of the Earth; the core-mantle boundary (experiments and seismic velocity profiles); the upper mantle-lower mantle boundary and the transition zone (also experiments and velocity profiles), the crust-mantle boundary, and the base of the lithosphere. Because continental crus ...
Neo-Tethys geodynamics and mantle convection: from - HAL-Insu
... Obduction of the Neo-Tethys ophiolites High-pressure and low-temperature (HP–LT) metamorphic conditions recorded in the tectonic units found below ophiolites do not differ from those retrieved in Alpine-type mountain belts and show that obduction results from subduction of the former continental mar ...
... Obduction of the Neo-Tethys ophiolites High-pressure and low-temperature (HP–LT) metamorphic conditions recorded in the tectonic units found below ophiolites do not differ from those retrieved in Alpine-type mountain belts and show that obduction results from subduction of the former continental mar ...
GPlates Tutorial Plate Reconstructions
... plates for some period during its geological history. A Plate ID is a non-negative integer number. Tectonic elements can include anything from large plates to island arcs and relatively small blocks or terranes in regions experiencing complex deformation. In GPlates we also assign separate plate ID’ ...
... plates for some period during its geological history. A Plate ID is a non-negative integer number. Tectonic elements can include anything from large plates to island arcs and relatively small blocks or terranes in regions experiencing complex deformation. In GPlates we also assign separate plate ID’ ...
The Southern Sierra Nevada Drip and the Mantle Wind Direction
... about 12 km. These simple calculations suggest that a thick garnet pyroxenite batholithic root, if it detaches as pieces larger than a few tens of kilometers in size, will sink rapidly through the asthenospheric mantle, reaching the mantle transition zone in less than 1 m.y. This analysis and the ge ...
... about 12 km. These simple calculations suggest that a thick garnet pyroxenite batholithic root, if it detaches as pieces larger than a few tens of kilometers in size, will sink rapidly through the asthenospheric mantle, reaching the mantle transition zone in less than 1 m.y. This analysis and the ge ...
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 ...
Finite-frequency wave propagation through outer rise fault zones
... We modeled acoustic-wave propagation though 100, 200, and 500 m wide, serpentinized joints in a uniform, background mantle. Effective wave speeds in these models are anisotropic, with slower wave speeds in the joint-perpendicular direction and faster wave speeds parallel to joints, with wavefronts i ...
... We modeled acoustic-wave propagation though 100, 200, and 500 m wide, serpentinized joints in a uniform, background mantle. Effective wave speeds in these models are anisotropic, with slower wave speeds in the joint-perpendicular direction and faster wave speeds parallel to joints, with wavefronts i ...
Possible density segregation of subducted oceanic
... consequence, the entire crust is in the brittle regime [19– 22]. However, if the top of the lithospheric mantle has been serpentinized, then a weak zone is expected to exist because of serpentine's exceedingly low strength when compared with unaltered peridotite and basalt [23,24]. Several lines of ...
... consequence, the entire crust is in the brittle regime [19– 22]. However, if the top of the lithospheric mantle has been serpentinized, then a weak zone is expected to exist because of serpentine's exceedingly low strength when compared with unaltered peridotite and basalt [23,24]. Several lines of ...
Oceanic trench
The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few mm to over ten cm per year. A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to a volcanic island arc, and about 200 km (120 mi) from a volcanic arc. Oceanic trenches typically extend 3 to 4 km (1.9 to 2.5 mi) below the level of the surrounding oceanic floor. The greatest ocean depth to be sounded is in the Challenger Deep of the Mariana Trench, at a depth of 11,034 m (36,201 ft) below sea level. Oceanic lithosphere moves into trenches at a global rate of about 3 km2/yr.