Subducting slabs: Jellyfishes in the Earth`s mantle
... shows that the lithosphere does not subduct as a slab of uniform thickness but is rather thinned in the upper mantle and thickened around the transition zone between the upper and lower mantle. This observation has traditionally been interpreted as evidence for the buckling and piling of slabs at th ...
... shows that the lithosphere does not subduct as a slab of uniform thickness but is rather thinned in the upper mantle and thickened around the transition zone between the upper and lower mantle. This observation has traditionally been interpreted as evidence for the buckling and piling of slabs at th ...
Spontaneous development of arcuate single‐sided subduction in
... Subduction zones are one of the most prominent features on a planet that undergoes plate tectonics, not only in terms of surface morphology but also in terms of the planet’s dynamic evolution. Its importance for the dynamics is highlighted by the fact that the sinking portions of a plate (i.e., slab ...
... Subduction zones are one of the most prominent features on a planet that undergoes plate tectonics, not only in terms of surface morphology but also in terms of the planet’s dynamic evolution. Its importance for the dynamics is highlighted by the fact that the sinking portions of a plate (i.e., slab ...
Origin of carbonatites in the South Qinling orogen:
... Most studies of compositional heterogeneities in the mantle, related to recycling of crustal sediments or delaminated subcontinental lithosphere, come from oceanic setting basalts. In this work, we present direct geochronological and geochemical evidence for the incorporation of recycled crustal mat ...
... Most studies of compositional heterogeneities in the mantle, related to recycling of crustal sediments or delaminated subcontinental lithosphere, come from oceanic setting basalts. In this work, we present direct geochronological and geochemical evidence for the incorporation of recycled crustal mat ...
How do subduction processes contribute to forearc - HAL-Insu
... It is well known since Darwin (1846) that segments of the Pacific coasts of South America are rapidly uplifting. Although obscured by rapid short-term vertical displacements resulting from the seismic cycle, long-term (at geological time-scales) coastal uplift is evidenced by well preserved paleosho ...
... It is well known since Darwin (1846) that segments of the Pacific coasts of South America are rapidly uplifting. Although obscured by rapid short-term vertical displacements resulting from the seismic cycle, long-term (at geological time-scales) coastal uplift is evidenced by well preserved paleosho ...
︎PDF - Fabio Crameri
... Subduction zones are one of the most prominent features on a planet that undergoes plate tectonics, not only in terms of surface morphology but also in terms of the planet’s dynamic evolution. Its importance for the dynamics is highlighted by the fact that the sinking portions of a plate (i.e., slab ...
... Subduction zones are one of the most prominent features on a planet that undergoes plate tectonics, not only in terms of surface morphology but also in terms of the planet’s dynamic evolution. Its importance for the dynamics is highlighted by the fact that the sinking portions of a plate (i.e., slab ...
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 ...
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 ...
physical, chemical, and chronological characteristics of
... are seen under tectonically active continental regions, such as the Basin and Range, but available evidence indicates that in these continental areas the mantle low-velocity zone begins immediately beneath the Moho, with a high-velocity ‘‘lid’’ similar to that seen in ocean basins notably absent. Lo ...
... are seen under tectonically active continental regions, such as the Basin and Range, but available evidence indicates that in these continental areas the mantle low-velocity zone begins immediately beneath the Moho, with a high-velocity ‘‘lid’’ similar to that seen in ocean basins notably absent. Lo ...
Author`s personal copy
... western U.S., during the mid-Tertiary “ignimbrite flare-up”, principally at the San Juan and Mogollon-Datil volcanic fields. At both volcanic centers, radiogenic isotope data have been interpreted as evidence that 50% or more of the volcanic rocks (by mass) were derived from mantle-derived, mafic pa ...
... western U.S., during the mid-Tertiary “ignimbrite flare-up”, principally at the San Juan and Mogollon-Datil volcanic fields. At both volcanic centers, radiogenic isotope data have been interpreted as evidence that 50% or more of the volcanic rocks (by mass) were derived from mantle-derived, mafic pa ...
Chemical Geodynamics - Woods Hole Oceanographic Institution
... eruptives of a single small seamount (10-km base diameter, 42-km 3 volume) (Zindler et al 1 984). In the seamount case, it seems unlikely that this variability can be ascribed to several major mantle plumes coming from disparate depths. Zindler et al (1984) used these data to argue for a mantle that ...
... eruptives of a single small seamount (10-km base diameter, 42-km 3 volume) (Zindler et al 1 984). In the seamount case, it seems unlikely that this variability can be ascribed to several major mantle plumes coming from disparate depths. Zindler et al (1984) used these data to argue for a mantle that ...
univERsity oF copEnhAGEn
... to form magma that, after solidification, will have the characteristic 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, whi ...
... to form magma that, after solidification, will have the characteristic 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, whi ...
Moho and magmatic underplating
... to form magma that, after solidification, will have the characteristic 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, whi ...
... to form magma that, after solidification, will have the characteristic 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, whi ...
pdf file - University of Victoria
... Lower crust flow has previously been concluded for several areas of tectonically thickened orogenic crust. The most studied currently active case is the Tibet high plateau and its flanks (e.g., Clark and Royden, 2000; Beaumont et al., 2001; 2004; 2006; Godin et al., 2006; Klemperer, 2006; Harris, 20 ...
... Lower crust flow has previously been concluded for several areas of tectonically thickened orogenic crust. The most studied currently active case is the Tibet high plateau and its flanks (e.g., Clark and Royden, 2000; Beaumont et al., 2001; 2004; 2006; Godin et al., 2006; Klemperer, 2006; Harris, 20 ...
Alignment between seafloor spreading directions and absolute plate
... are typically <20° in the Pacific for all APM models and between 10 and 40° for spreading in the Indian and Atlantic domains. Over the last 130 Myr, the time-dependent histograms illustrate a clear contrast between the results for the Indo-Atlantic domains and Pacific domain. In the Atlantic domain, t ...
... are typically <20° in the Pacific for all APM models and between 10 and 40° for spreading in the Indian and Atlantic domains. Over the last 130 Myr, the time-dependent histograms illustrate a clear contrast between the results for the Indo-Atlantic domains and Pacific domain. In the Atlantic domain, t ...
Continent–ocean transition and voluminous magmatic underplating
... χ 2 values. For profile AWI-20030500 largest deviations to the optimum normalized χ 2 value of 1.0 are caused by small error values for the Pw phases or larger misfits to Pc2 picks and yield values of 8.294 and 14.112, respectively (Table 1). Highest t rms values of profile AWI-20030400 occur at pha ...
... χ 2 values. For profile AWI-20030500 largest deviations to the optimum normalized χ 2 value of 1.0 are caused by small error values for the Pw phases or larger misfits to Pc2 picks and yield values of 8.294 and 14.112, respectively (Table 1). Highest t rms values of profile AWI-20030400 occur at pha ...
thrust systems - The Web site cannot be found
... - Collision tectonics involves thickening and imbrication of the crust and lithospheric mantle when the ocean closes. Hence an orogenic belt is generally aligned along a zone of continental collision. Deformation produces excess topography (mountain range) that erosion modifies and destroys on a lon ...
... - Collision tectonics involves thickening and imbrication of the crust and lithospheric mantle when the ocean closes. Hence an orogenic belt is generally aligned along a zone of continental collision. Deformation produces excess topography (mountain range) that erosion modifies and destroys on a lon ...
Geophysical Journal International
... to the geological structure and constrained by existing data. The conductive heat transport equation is solved by using the finite element method in steady-state, with the following boundary conditions: 0 ◦ C at the surface; 1330 ◦ C at the lithosphere– asthenosphere boundary (LAB); and no heat flow ...
... to the geological structure and constrained by existing data. The conductive heat transport equation is solved by using the finite element method in steady-state, with the following boundary conditions: 0 ◦ C at the surface; 1330 ◦ C at the lithosphere– asthenosphere boundary (LAB); and no heat flow ...
Magma genesis, plate tectonics, and chemical
... oceanicplates, and (4) continental plates.These may be subdiMAGMA GENESIS AND PLATE TECTONICS vided. Divergent plate boundariesinclude (1A) oceanic ridges The main variables to be consideredin magma genesisare and (lB) continental rift systems.Convergent plate boundaries (1) the compositionsof mater ...
... oceanicplates, and (4) continental plates.These may be subdiMAGMA GENESIS AND PLATE TECTONICS vided. Divergent plate boundariesinclude (1A) oceanic ridges The main variables to be consideredin magma genesisare and (lB) continental rift systems.Convergent plate boundaries (1) the compositionsof mater ...
Plume mantle source heterogeneity through time: Insights from the
... in Costa Rica and in other Cretaceous oceanic plateaus from the western Pacific [Neal et al., 1997; Ernst et al., 2005], where plume magmatism occurred for 50 Ma or more at variable eruptive rates. The youngest CCOP rocks are found in the Dominican Republic (69 Ma) and the Quepos Peninsula of Costa ...
... in Costa Rica and in other Cretaceous oceanic plateaus from the western Pacific [Neal et al., 1997; Ernst et al., 2005], where plume magmatism occurred for 50 Ma or more at variable eruptive rates. The youngest CCOP rocks are found in the Dominican Republic (69 Ma) and the Quepos Peninsula of Costa ...
Ringwood Phase transformations and their bearing on the
... bulk chemical composition of the Upper Mantle (“pyrolite”) is derived from experimental and petrological studies of the complementary relationships between basaltic magmas and refractory peridotites. The phase transformations which are experienced by pyrolite between depths of 100-800 km are reviewe ...
... bulk chemical composition of the Upper Mantle (“pyrolite”) is derived from experimental and petrological studies of the complementary relationships between basaltic magmas and refractory peridotites. The phase transformations which are experienced by pyrolite between depths of 100-800 km are reviewe ...
Primitive off-rift basalts from Iceland and Jan Mayen: Os
... melting characteristics from the surrounding mantle, with the fracture zone and the nearby spreading axis. The continental material would have been left over from the opening of the Atlantic Ocean and dispersed within the upper mantle. However, ITE concentrations of Jan Mayen lavas are not compatibl ...
... melting characteristics from the surrounding mantle, with the fracture zone and the nearby spreading axis. The continental material would have been left over from the opening of the Atlantic Ocean and dispersed within the upper mantle. However, ITE concentrations of Jan Mayen lavas are not compatibl ...
Mid-Ocean Ridges: Mantle Convection and Formation
... circulation. This cooling generates a thermal boundary layer, which is rigid to convection and is the newly created edge of the tectonic plate. As the lithosphere moves away from the ridge, it thickens via additional cooling, becomes denser, and sinks deeper into the underlying ductile asthenosphere ...
... circulation. This cooling generates a thermal boundary layer, which is rigid to convection and is the newly created edge of the tectonic plate. As the lithosphere moves away from the ridge, it thickens via additional cooling, becomes denser, and sinks deeper into the underlying ductile asthenosphere ...
Mechanical (de-)coupling of the lithosphere in the Valencia Trough
... We study the mechanics of lithospheric decoupling in continental extensional basins in relation to the distribution of (non-)competent mechanical layers within the lithosphere and the position of the isostatic compensation level. We specifically address the different modes of deformation taking plac ...
... We study the mechanics of lithospheric decoupling in continental extensional basins in relation to the distribution of (non-)competent mechanical layers within the lithosphere and the position of the isostatic compensation level. We specifically address the different modes of deformation taking plac ...
Triggering of the largest Deccan eruptions by the Chicxulub impact
... New constraints on the timing of the Cretaceous-Paleogene mass extinction and the Chicxulub impact, together with a particularly voluminous and apparently brief eruptive pulse toward the end of the “main-stage” eruptions of the Deccan continental flood basalt province suggest that these three events ...
... New constraints on the timing of the Cretaceous-Paleogene mass extinction and the Chicxulub impact, together with a particularly voluminous and apparently brief eruptive pulse toward the end of the “main-stage” eruptions of the Deccan continental flood basalt province suggest that these three events ...
Setting Based Classification
... Contact Metamorphism Polymetamorphic rocks are common, usually representing an orogenic event followed by a contact one • Spotted phyllite (or slate) • Overprint may be due to: – Lag time between the creation of the magma at depth during T maximum, and its migration to the lower grade rocks above ...
... Contact Metamorphism Polymetamorphic rocks are common, usually representing an orogenic event followed by a contact one • Spotted phyllite (or slate) • Overprint may be due to: – Lag time between the creation of the magma at depth during T maximum, and its migration to the lower grade rocks above ...
Supercontinent
In geology, a supercontinent is the assembly of most or all of the Earth's continental blocks or cratons to form a single large landmass. However, the definition of a supercontinent can be ambiguous. Many tectonicists such as P.F. Hoffman (1999) use the term ""supercontinent"" to mean ""a clustering of nearly all continents"". This definition leaves room for interpretation when labeling a continental body and is easier to apply to Precambrian times. Using the first definition provided here, Gondwana (aka Gondwanaland) is not considered a supercontinent, because the landmasses of Baltica, Laurentia and Siberia also existed at the same time but physically separate from each other. The landmass of Pangaea is the collective name describing all of these continental masses when they were in a close proximity to one another. This would classify Pangaea as a supercontinent. According to the definition by Rogers and Santosh (2004), a supercontinent does not exist today. Supercontinents have assembled and dispersed multiple times in the geologic past (see table). The positions of continents have been accurately determined back to the early Jurassic. However, beyond 200 Ma, continental positions are much less certain.