Thematic Article A bathymetric overview of the Mariana forearc
... Abstract Bathymetric data at a 200-m contour interval for the entire Mariana forearc, from south of 13°N to 25°N, permits the ®rst comprehensive overview of this feature. The Mariana forearc represents a sediment-starved end-member. The forearc in its southern and central sections is divisible into ...
... Abstract Bathymetric data at a 200-m contour interval for the entire Mariana forearc, from south of 13°N to 25°N, permits the ®rst comprehensive overview of this feature. The Mariana forearc represents a sediment-starved end-member. The forearc in its southern and central sections is divisible into ...
Serpentinization of the forearc mantle
... beneath the forearc, whereas smaller amounts are expected to be released at depths of arc magma generation and beneath the backarc. Note that in this text we use ‘water’ for H2 0, although the conditions may be such that it is a supercritical £uid. In this article we document the wide range of geolo ...
... beneath the forearc, whereas smaller amounts are expected to be released at depths of arc magma generation and beneath the backarc. Note that in this text we use ‘water’ for H2 0, although the conditions may be such that it is a supercritical £uid. In this article we document the wide range of geolo ...
Mantle structure and tectonic history of SE Asia
... We discuss tomography and tectonic interpretations of an area centred on Indonesia and including Malaysia, parts of the Philippines, New Guinea and northern Australia. We begin with an explanation of seismic tomography and causes of velocity anomalies in the mantle, and discuss assessment of model q ...
... We discuss tomography and tectonic interpretations of an area centred on Indonesia and including Malaysia, parts of the Philippines, New Guinea and northern Australia. We begin with an explanation of seismic tomography and causes of velocity anomalies in the mantle, and discuss assessment of model q ...
Trace Element and Isotope Geochemistry of the Volcanic Rocks of
... are higher and Nd ratios are lower than those of the IHS. The the Lesser Antillean arc (Fig. 1), which formed along IDS is also characterized by high dla0 values, up to 7-6 in the eastern edge of the Caribbean Plate as a result of clinopyroxene. The Sr and Pb isotope ratios are too high, and the sub ...
... are higher and Nd ratios are lower than those of the IHS. The the Lesser Antillean arc (Fig. 1), which formed along IDS is also characterized by high dla0 values, up to 7-6 in the eastern edge of the Caribbean Plate as a result of clinopyroxene. The Sr and Pb isotope ratios are too high, and the sub ...
︎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 ...
The stability of arc lower crust: Insights from the Talkeetna Arc
... data to constrain the conditions of igneous crystallization in arc lower crust and to determine whether lower crustal foundering is a likely, ongoing process in modern arcs. Using the Talkeetna arc section as a compositional model, we calculate crystallizing mineral assemblages for a range of gabbro ...
... data to constrain the conditions of igneous crystallization in arc lower crust and to determine whether lower crustal foundering is a likely, ongoing process in modern arcs. Using the Talkeetna arc section as a compositional model, we calculate crystallizing mineral assemblages for a range of gabbro ...
Mechanism and timing of Pb transport from subducted oceanic crust
... Tonga Trench are well-known from studies of sediments drilled at DSDP Sites 204, 595 and 596 (see Fig. 1; Menard et al., 1987; Zhou and Kyte, 1992; Turner et al., 1997; Ewart et al., 1998; Plank and Langmuir, 1998). At Site 596, approximately 70 m of pelagic and metalliferous clay, chert and hydroth ...
... Tonga Trench are well-known from studies of sediments drilled at DSDP Sites 204, 595 and 596 (see Fig. 1; Menard et al., 1987; Zhou and Kyte, 1992; Turner et al., 1997; Ewart et al., 1998; Plank and Langmuir, 1998). At Site 596, approximately 70 m of pelagic and metalliferous clay, chert and hydroth ...
Downdip landward limit of Cascadia great earthquake rupture
... physical controls of subduction thrust rupture globally. The constraints are (1) “locked/ transition” zones from geodetic deformation (GPS, repeated leveling, tide gauges); (2) rupture zone from paleoseismic coastal marsh subsidence, “paleogeodesy”; (3) temperature on the thrust for the seismic-asei ...
... physical controls of subduction thrust rupture globally. The constraints are (1) “locked/ transition” zones from geodetic deformation (GPS, repeated leveling, tide gauges); (2) rupture zone from paleoseismic coastal marsh subsidence, “paleogeodesy”; (3) temperature on the thrust for the seismic-asei ...
Origin and consequences of western Mediterranean subduction
... here. NW-SE shortening in the Central Iberian Ranges was reconstructed at 20 km between 35 and 20 Ma [De Vicente et al., 2007] (see Table 1), although Guimera et al. [2004] estimated as much as 65 km. The estimates of total intraplate shortening thus vary from 30 to 95 km and were reconstructed as ~ ...
... here. NW-SE shortening in the Central Iberian Ranges was reconstructed at 20 km between 35 and 20 Ma [De Vicente et al., 2007] (see Table 1), although Guimera et al. [2004] estimated as much as 65 km. The estimates of total intraplate shortening thus vary from 30 to 95 km and were reconstructed as ~ ...
3.20 Trace Element and Isotopic Fluxes
... and metamorphism along the subduction pathway. The focus in this contribution is largely on the chemical and isotopic tracers commonly employed to elucidate chemical cycling in subduction zones based on study of arc lavas, and on discussion of metamorphic suites for which it is possible to evaluate ...
... and metamorphism along the subduction pathway. The focus in this contribution is largely on the chemical and isotopic tracers commonly employed to elucidate chemical cycling in subduction zones based on study of arc lavas, and on discussion of metamorphic suites for which it is possible to evaluate ...
Weakening of the subduction interface and its effects on surface
... mantle wedge is greater than that of the interface layer. We find that the maximum depth of decoupling is the key to most primary thermal and petrological processes in subduction zone forearcs. The forearc mantle wedge above a weakened subduction interface always becomes stagnant (<0.2% slab velocit ...
... mantle wedge is greater than that of the interface layer. We find that the maximum depth of decoupling is the key to most primary thermal and petrological processes in subduction zone forearcs. The forearc mantle wedge above a weakened subduction interface always becomes stagnant (<0.2% slab velocit ...
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 ...
Behavior of subducting sediments beneath an arc under a high
... geochemical feature suggests that there is no residual phase which can accommodate HFSE during the sediments melting. Furthermore, less-steep REE patterns of Setouchi HMAs and basalt imply the absence of residual zircon during the sediment melting (Shimoda et al. in prep.). These geochemical charact ...
... geochemical feature suggests that there is no residual phase which can accommodate HFSE during the sediments melting. Furthermore, less-steep REE patterns of Setouchi HMAs and basalt imply the absence of residual zircon during the sediment melting (Shimoda et al. in prep.). These geochemical charact ...
How do subduction processes contribute to forearc - HAL-Insu
... The Carnegie and Nazca ridges are the two largest aseismic ridges being subducted beneath South America. The Carnegie Ridge is subducting beneath Ecuador since at least 1.4 Myrs, but the proposed age for the onset of subduction is disputed and ranges from 1 to 15 Myrs (see Michaud et al., 2009, for ...
... The Carnegie and Nazca ridges are the two largest aseismic ridges being subducted beneath South America. The Carnegie Ridge is subducting beneath Ecuador since at least 1.4 Myrs, but the proposed age for the onset of subduction is disputed and ranges from 1 to 15 Myrs (see Michaud et al., 2009, for ...
PDF
... Four arc–arc sutures are identified in the Arabian– Nubian Shield. These are from north to south: the Yanbu–Onib–Sol Hamed–Gerf–Allaqi–Heiani sutures, the Nakasib–Bir Umq suture, the Baraka–Tulu Dimtu suture, and the Adola–Moyale suture (Abdelsalam and Stern, 1996). This work focuses on the western ...
... Four arc–arc sutures are identified in the Arabian– Nubian Shield. These are from north to south: the Yanbu–Onib–Sol Hamed–Gerf–Allaqi–Heiani sutures, the Nakasib–Bir Umq suture, the Baraka–Tulu Dimtu suture, and the Adola–Moyale suture (Abdelsalam and Stern, 1996). This work focuses on the western ...
Petrology and tectonics of Phanerozoic continent formation: From
... continent formation. We combine new trace-element data on lower crustal xenoliths from the Mesozoic Sierra Nevada Batholith with an extensive grid-based geochemical map of the Peninsular Ranges Batholith, the southern equivalent of the Sierras. Collectively, these observations give a three-dimension ...
... continent formation. We combine new trace-element data on lower crustal xenoliths from the Mesozoic Sierra Nevada Batholith with an extensive grid-based geochemical map of the Peninsular Ranges Batholith, the southern equivalent of the Sierras. Collectively, these observations give a three-dimension ...
Formation and Exhumation of Ultrahigh
... crustal stacking (FIG. 1). The model (Sizova et al. 2012) simulates subduction of a continental plate following closure of an ocean basin (FIG. 2A). The incoming continental passive margin subducts in a coherent manner, reaching depths of 100–150 km within 5.8 My (FIG. 2B). Buoyancy of the deeply su ...
... crustal stacking (FIG. 1). The model (Sizova et al. 2012) simulates subduction of a continental plate following closure of an ocean basin (FIG. 2A). The incoming continental passive margin subducts in a coherent manner, reaching depths of 100–150 km within 5.8 My (FIG. 2B). Buoyancy of the deeply su ...
Receiver function images of the Hellenic subduction zone and
... strongly imaged beneath the stations located relatively far from the Hellenic trench (see Fig. 1). At the stations located in the forearc of the subduction zone (marked Forearc in Fig. 2), the converted Moho phase with positive polarity disappeared and instead a negative phase is seen. Such a revers ...
... strongly imaged beneath the stations located relatively far from the Hellenic trench (see Fig. 1). At the stations located in the forearc of the subduction zone (marked Forearc in Fig. 2), the converted Moho phase with positive polarity disappeared and instead a negative phase is seen. Such a revers ...
Crust recycling in the sources of two parallel volcanic chains in
... are partially altered to low-temperature iddingsite. All samples have minor olivine (b 15%) as phenocrysts set in a groundmass of olivine, ...
... are partially altered to low-temperature iddingsite. All samples have minor olivine (b 15%) as phenocrysts set in a groundmass of olivine, ...
workshop report
... hypotheses can be tested by drilling, so we will focus solely on the role of subduction in creating juvenile crust. The presence of significant volume of middle crust with 6.0-6.8 km/s seismic velocities throughout the entire IBM arc (Calvert et al., 2008; Kodaira et al., 2007a,b; Kodaira et al., 20 ...
... hypotheses can be tested by drilling, so we will focus solely on the role of subduction in creating juvenile crust. The presence of significant volume of middle crust with 6.0-6.8 km/s seismic velocities throughout the entire IBM arc (Calvert et al., 2008; Kodaira et al., 2007a,b; Kodaira et al., 20 ...
eastern european alpine system and the carpathian
... mountain terranes their internal structural development is conspicuously diachronous and is dependent upon the relative motion of at least three fragments of continental crust which lay between the European and African plate. In Late Jurassic time the three fragments of continental crust were separa ...
... mountain terranes their internal structural development is conspicuously diachronous and is dependent upon the relative motion of at least three fragments of continental crust which lay between the European and African plate. In Late Jurassic time the three fragments of continental crust were separa ...
High-Mg# andesitic lavas of the Shisheisky Complex, Northern
... juvenile additions of andesitic crust or an important parental magma-type in subduction settings, but instead are produced by the interaction between mantle-derived basaltic melt and pre-existing crust. In this paper, we present whole-rock and mineral composition data for a suite of primitive, high- ...
... juvenile additions of andesitic crust or an important parental magma-type in subduction settings, but instead are produced by the interaction between mantle-derived basaltic melt and pre-existing crust. In this paper, we present whole-rock and mineral composition data for a suite of primitive, high- ...
1 Origin and geodynamic relationships of the Late Miocene to
... plume or plume fingers beneath this region. Instead, we propose that plate tectonic processes ...
... plume or plume fingers beneath this region. Instead, we propose that plate tectonic processes ...
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 ...
The Seismic Structure of Island Arc Crust
... sources, associated with subducting slab and upwelling asthenosphere, migrating past one another as backarc spreading develops (Martinez and Taylor 2006). When rifting occurs on the back-arc side of the arc massif, the remnant arc separates from the still unified magmatic arc and forearc through bac ...
... sources, associated with subducting slab and upwelling asthenosphere, migrating past one another as backarc spreading develops (Martinez and Taylor 2006). When rifting occurs on the back-arc side of the arc massif, the remnant arc separates from the still unified magmatic arc and forearc through bac ...
Cascade Volcanoes
This article is for the volcanic arc. For the namesake mountain range see Cascade Range.The Cascade Volcanoes (also known as the Cascade Volcanic Arc or the Cascade Arc) are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern California, a distance of well over 700 miles (1,100 km). The arc has formed due to subduction along the Cascadia subduction zone. Although taking its name from the Cascade Range, this term is a geologic grouping rather than a geographic one, and the Cascade Volcanoes extend north into the Coast Mountains, past the Fraser River which is the northward limit of the Cascade Range proper.Some of the major cities along the length of the arc include Portland, Seattle, and Vancouver, and the population in the region exceeds 10,000,000. All could be potentially affected by volcanic activity and great subduction-zone earthquakes along the arc. Because the population of the Pacific Northwest is rapidly increasing, the Cascade volcanoes are some of the most dangerous, due to their eruptive history and potential for future eruptions, and because they are underlain by weak, hydrothermally altered volcanic rocks that are susceptible to failure. Consequently, Mount Rainier is one of the Decade Volcanoes identified by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) as being worthy of particular study, due to the danger it poses to Seattle and Tacoma. Many large, long-runout landslides originating on Cascade volcanoes have inundated valleys tens of kilometers from their sources, and some of the inundated areas now support large populations.The Cascade Volcanoes are part of the Pacific Ring of Fire, the ring of volcanoes and associated mountains around the Pacific Ocean. All of the known historic eruptions in the contiguous United States have been from the Cascade Volcanoes. Two most recent were Lassen Peak in 1914 to 1921 and a major eruption of Mount St. Helens in 1980. It is also the site of Canada's most recent major eruption about 2,350 years ago at the Mount Meager volcanic complex.