The southwestern edge of the Ryukyu subduction zone: A high Q mantle wedge

2012 ◽  
Vol 335-336 ◽  
pp. 145-153 ◽  
Author(s):  
Yen-Ting Ko ◽  
Ban-Yuan Kuo ◽  
Kuo-Lung Wang ◽  
Shu-Chuan Lin ◽  
Shu-Huei Hung
Keyword(s):  
Subduction Zone ◽  
Mantle Wedge ◽  
High Q

scholarly journals Seismic evidence for flow in the hydrated mantle wedge of the Ryukyu subduction zone

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Takayoshi Nagaya ◽  
Andrew M. Walker ◽  
James Wookey ◽  
Simon R. Wallis ◽  
Kazuhiko Ishii ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Mantle Wedge

scholarly journals Ophiolitic Pyroxenites Record Boninite Percolation in Subduction Zone Mantle

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 565 ◽  
Author(s):  
Véronique Le Roux ◽  
Yan Liang
Keyword(s):  
Subduction Zone ◽  
Subduction Zones ◽  
Mantle Wedge ◽  
Major Element ◽  
Early Stage ◽  
Diffusion Modeling ◽  
Melt Infiltration ◽  
Melt Percolation ◽  
Back Arc ◽  
Parental Melts

The peridotite section of supra-subduction zone ophiolites is often crosscut by pyroxenite veins, reflecting the variety of melts that percolate through the mantle wedge, react, and eventually crystallize in the shallow lithospheric mantle. Understanding the nature of parental melts and the timing of formation of these pyroxenites provides unique constraints on melt infiltration processes that may occur in active subduction zones. This study deciphers the processes of orthopyroxenite and clinopyroxenite formation in the Josephine ophiolite (USA), using new trace and major element analyses of pyroxenite minerals, closure temperatures, elemental profiles, diffusion modeling, and equilibrium melt calculations. We show that multiple melt percolation events are required to explain the variable chemistry of peridotite-hosted pyroxenite veins, consistent with previous observations in the xenolith record. We argue that the Josephine ophiolite evolved in conditions intermediate between back-arc and sub-arc. Clinopyroxenites formed at an early stage of ophiolite formation from percolation of high-Ca boninites. Several million years later, and shortly before exhumation, orthopyroxenites formed through remelting of the Josephine harzburgites through percolation of ultra-depleted low-Ca boninites. Thus, we support the hypothesis that multiple types of boninites can be created at different stages of arc formation and that ophiolitic pyroxenites uniquely record the timing of boninite percolation in subduction zone mantle.

The importance of mantle wedge heterogeneity to subduction zone magmatism and the origin of EM1

2017 ◽  
Vol 472 ◽  
pp. 216-228 ◽  
Author(s):  
Stephen J. Turner ◽  
Charles H. Langmuir ◽  
Michael A. Dungan ◽  
Stephane Escrig
Keyword(s):  
Subduction Zone ◽  
Mantle Wedge ◽  
Subduction Zone Magmatism

scholarly journals Geochemistry, Sr–Nd–Pb isotopes and geochronology of amphibole- and mica-bearing lamprophyres in northwestern Iran: Implications for mantle wedge heterogeneity in a palaeo-subduction zone

Lithos ◽  
2015 ◽  
Vol 216-217 ◽  
pp. 352-369 ◽  
Author(s):  
Mehraj Aghazadeh ◽  
Dejan Prelević ◽  
Zahra Badrzadeh ◽  
Eleonora Braschi ◽  
Paul van den Bogaard ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Mantle Wedge ◽  
Pb Isotopes ◽  
Northwestern Iran

scholarly journals New constraints on the geometry of the subducting African plate and the overriding Aegean plate obtained from P receiver functions and seismicity

2013 ◽  
Vol 5 (1) ◽  
pp. 427-461 ◽  
Author(s):  
F. Sodoudi ◽  
A. Bruestle ◽  
T. Meier ◽  
R. Kind ◽  
W. Friederich ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Mantle Wedge ◽  
Receiver Functions ◽  
Moho Depth ◽  
Crustal Material ◽  
Mantle Lithosphere ◽  
African Plate ◽  
Western Turkey ◽  
Hellenic Subduction Zone ◽  
Eastern Aegean

Abstract. New combined P receiver functions and seismicity data obtained from the EGELADOS network employing 65 stations within the Aegean constrained new information on the geometry of the Hellenic subduction zone. The dense network and large dataset enabled us to accurately estimate the Moho of the continental Aegean plate across the whole area. Presence of a negative contrast at the Moho boundary indicating the serpentinized mantle wedge above the subducting African plate was clearly seen along the entire forearc. Furthermore, low seismicity was observed within the serpentinized mantle wedge. We found a relatively thick continental crust (30–43 km) with a maximum thickness of about 48 km beneath the Peloponnesus Peninsula, whereas a thinner crust of about 27–30 km was observed beneath western Turkey. The crust of the overriding plate is thinning beneath the southern and central Aegean (Moho depth 23–27 km). Moreover, P receiver functions significantly imaged the subducted African Moho as a strong converted phase down to a depth of 180 km. However, the converted Moho phase appears to be weak for the deeper parts of the African plate suggesting reduced dehydration and nearly complete phase transitions of crustal material into denser phases. We show the subducting African crust along 8 profiles covering the whole southern and central Aegean. Seismicity of the western Hellenic subduction zone was taken from the relocated EHB-ISC catalogue, whereas for the eastern Hellenic subduction zone, we used the catalogues of manually picked hypocenter locations of temporary networks within the Aegean. P receiver function profiles significantly revealed in good agreement with the seismicity a low dip angle slab segment down to 200 km depth in the west. Even though, the African slab seems to be steeper in the eastern Aegean and can be followed down to 300 km depth implying lower temperatures and delayed dehydration towards larger depths in the eastern slab segment. Our results showed that the transition between the western and eastern slab segments is located beneath the southeastern Aegean crossing eastern Crete and the Karpathos basin. High resolution P receiver functions also clearly resolved the top of a strong low velocity zone (LVZ) at about 60 km depth. This LVZ is interpreted as asthenosphere below the Aegean continental lithosphere and above the subducting slab. Thus the Aegean mantle lithosphere seems to be 30–40 km thick, which means that its thickness increased again since the removal of the mantle lithosphere about 15 to 35 Ma ago.

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