scholarly journals Seismic anisotropy of the Pacific slab and mantle wedge beneath the Japanese islands

2009 ◽  
Vol 114 (B7) ◽  
Author(s):  
Yoko Tono ◽  
Yoshio Fukao ◽  
Takashi Kunugi ◽  
Seiji Tsuboi
Keyword(s):  
Mantle Wedge ◽  
Seismic Anisotropy ◽  
The Pacific ◽  
Pacific Slab ◽  
Japanese Islands

Olivine chemistry of the Quaternary Datong basalts of the Trans-North China Orogen: Insights into mantle source lithology and redox–hydration state

2020 ◽  
pp. SP510-2020-142
Author(s):  
Lubing Hong ◽  
Zhang Yinhui ◽  
Le Zhang ◽  
Yi-Gang Xu ◽  
Zhe Liu ◽  
...  
Keyword(s):  
Oceanic Crust ◽  
Mantle Source ◽  
Partition Coefficients ◽  
North China ◽  
Mantle Wedge ◽  
Content Type ◽  
The Pacific ◽  
Hydration State ◽  
Pacific Slab ◽  
Supplementary Material

AbstractCenozoic intraplate basalts are widespread above the Big Mantle Wedge (BMW) and its front in East Asia. While the mantle source lithology and redox-hydration state have been demonstrated to be crucial in generation of the basalts above the BMW, their nature and role on the basalts above the front of the BMW is poorly constrained. To address this, we report olivine compositions of the Quaternary Datong basalts. The Datong basalts exhibit OIB-like trace-element compositions and depleted Sr-Nd isotopes with slightly enriched signatures (EMI) for tholeiitic basalts. Olivines of the Datong basalts show high Ni and Fe/Mn, and low Ca, Mn, and Mn/Zn values, pointing to a pyroxenite source. Applying V and Ca partition coefficients between olivine and whole-rock, respectively, the Datong basalts lie −0.44 to 0.64 log units above the fayalite-magnetite-quartz buffer for fO2, and contain 2.1-3.4 wt.% H2O but highly variable H2O/Ce values (265-1498). Both fO2 and H2O/Ce in the basalts vary with whole-rock and olivine compositions, indicating the source was the main control, thus, a heterogeneous redox-hydration state in the source: the EMI component being relatively reduced but extremely wet, and recycled oceanic crust being relatively oxidized but dry. The extremely wet EMI component was likely derived from the mantle transition zone. In the light of our findings, we propose a model in which mantle upwelling carried the recycled oceanic crust and EMI component from the MTZ to shallow mantle, due to the Pacific slab stagnating in the MTZ, to form pyroxenite, which subsequently melted to generate the Datong basalts.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5227668

scholarly journals Overriding plate, mantle wedge, slab, and subslab contributions to seismic anisotropy beneath the northern Central Andean Plateau

2016 ◽  
Vol 17 (7) ◽  
pp. 2556-2575 ◽  
Author(s):  
Maureen D. Long ◽  
C. Berk Biryol ◽  
Caroline M. Eakin ◽  
Susan L. Beck ◽  
Lara S. Wagner ◽  
...  
Keyword(s):  
Mantle Wedge ◽  
Seismic Anisotropy

Genetic homogeneity between adult and juvenile populations of Scombrops gilberti (Percoid, Scombropidae) in the Pacific Ocean off the Japanese Islands

2011 ◽  
Vol 77 (6) ◽  
pp. 975-981 ◽  
Author(s):  
Shiro Itoi ◽  
Junpei Odaka ◽  
Shunsuke Noguchi ◽  
Tsutomu Noda ◽  
Kohei Yuasa ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Genetic Homogeneity ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Japanese Islands

scholarly journals Supplemental Material: Seismic anisotropy in southern Costa Rica confirms upper mantle flow from the Pacific to the Caribbean

2020 ◽  
Author(s):  
Vadim Levin ◽  
et al.
Keyword(s):  
Data Analysis ◽  
Costa Rica ◽  
Upper Mantle ◽  
Seismic Anisotropy ◽  
Data Sources ◽  
Mantle Flow ◽  
Analysis Methodology ◽  
The Pacific ◽  
Wave Splitting ◽  
The Caribbean

Data sources, details of data analysis methodology, and additional diagrams and maps of shear wave splitting measurements.<br>

Modeling of convective heat-mass transfer in permeable parts of seismic focal zones of the Kamchatka region and associated volcanic arcs

2021 ◽  
Author(s):  
Yuri Perepechko ◽  
Konstantin Sorokin ◽  
Anna Mikheeva ◽  
Viktor Sharapov ◽  
Sherzad Imomnazarov
Keyword(s):  
Mass Transfer ◽  
Mantle Wedge ◽  
Earth’S Crust ◽  
Magma Chambers ◽  
Volcanic Arcs ◽  
Fluid Systems ◽  
The Pacific ◽  
Kamchatka Region ◽  
The Pacific Ocean ◽  
Earth's Crust

&lt;p&gt;The paper presents a non-isothermal model of hydrodynamic heating of lithospheric rocks above magma chambers in application to the seismic focal zone of the Kamchatka region and associated volcanic arcs. The effect of convective heating of mantle and crustal rocks on dynamics of metasomatic changes and convective melting was studied. In the existing models of ore-forming systems, fluid mass transfer is determined mainly by the retrograde boiling of magmas in meso-abyssal intrusive chambers. Analysis of the manifestations of deposits of the porphyry formation of the Pacific Ocean active margins shows the decisive participation in their formation of mantle-crust ore-igneous systems. The model of convective heat-mass transfer in fluid mantle-crust systems coupled with magma chambers is designed with the consideration of effects of interphase interaction in rocks of permeable zones above igneous fluid sources. Numerical simulation of the dynamics of fluid systems under the volcanoes of the frontal zone of Kamchatka shows altered ultramafic rocks in metasomatic zoning and the presence of facial changes in the mineral composition of wehrlitized rocks. In the mantle wedge of the northwestern margin of the Pacific Ocean, over which epicontinental volcanic arcs developed in the post-Miocene stage, there is possible combination of the products of different-time and different-level igneous systems in the same permeable &quot;earth's crust-lithospheric mantle&quot; transition zones. Assuming that the &quot;cratonization&quot; of volcanic sections of the continental Earth's crust follows the &quot;metasomatic granitization&quot; pattern, the initial element of which is the wehrlitization of mantle wedge ultramafic rocks, the processes of metasomatic fertilization of mantle wedge rocks were investigated using a flow-through multiple-reservoir reactor. In the seismically active regions of the Pacific transition lithosphere, specific conditions for heating of areas of increased permeability above mantle fluid sources should be recorded. Metasomatic columns in such fluid systems can describe the formation of at least three levels of convective melting of metasomatized mantle wedge substrates, as well as the formation of a region of high-temperature fluid change of mafic intrusion rocks in the Earth's crust. The work was financially supported by the Russian Foundation for Basic Research, grants No. 19-05-00788.&lt;/p&gt;

scholarly journals Seismic anisotropy reveals crustal flow driven by mantle vertical loading in the Pacific NW

2020 ◽  
Vol 6 (28) ◽  
pp. eabb0476
Author(s):  
Jorge C. Castellanos ◽  
Jonathan Perry-Houts ◽  
Robert W. Clayton ◽  
YoungHee Kim ◽  
A. Christian Stanciu ◽  
...  
Keyword(s):  
Pacific Northwest ◽  
Upper Mantle ◽  
Seismic Anisotropy ◽  
Azimuthal Anisotropy ◽  
Mantle Flow ◽  
Near Surface ◽  
Vertical Loading ◽  
The Pacific ◽  
Anisotropy Model ◽  
Lithosphere Dynamics

Buoyancy anomalies within Earth’s mantle create large convective currents that are thought to control the evolution of the lithosphere. While tectonic plate motions provide evidence for this relation, the mechanism by which mantle processes influence near-surface tectonics remains elusive. Here, we present an azimuthal anisotropy model for the Pacific Northwest crust that strongly correlates with high-velocity structures in the underlying mantle but shows no association with the regional mantle flow field. We suggest that the crustal anisotropy is decoupled from horizontal basal tractions and, instead, created by upper mantle vertical loading, which generates pressure gradients that drive channelized flow in the mid-lower crust. We then demonstrate the interplay between mantle heterogeneities and lithosphere dynamics by predicting the viscous crustal flow that is driven by local buoyancy sources within the upper mantle. Our findings reveal how mantle vertical load distribution can actively control crustal deformation on a scale of several hundred kilometers.

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