Comparative geodynamics of Aleutian and Izu-Bonin-Mariana island-arc systems
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چکیده
منابع مشابه
Origin of depleted basalts during subduction initiation and early development of the Izu-Bonin-Mariana Island arc: Evidence from IODP Expedition 351 Site U1438, Amami-Sankaku Basin
The Izu-Bonin-Mariana (IBM) island arc formed following initiation of subduction of the Pacific plate beneath the Philippine Sea plate at about 52 Ma. Site U1438 of IODP Expedition 351 was drilled to sample the oceanic basement on which the IBM arc was constructed, to better understand magmatism prior to and during the subduction initiation event. Site U1438 igneous basement Unit 1 (150 m) was ...
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Pumice samples from Fukutoku-oka-no-ba in the Izu±Bonin ± Mariana (IBM) arc were analysed for 40 trace elements and Sr, Nd, and Pb isotopic compositions. These samples are shoshonites (59.4±61.8 wt% SiO2), characterized by high contents of K2O (3.74±4.64 wt%), Ba (1274±1540 p.p.m.), Rb (91±105 p.p.m.), and light rare earth elements. The characteristics of alkali-element enrichment are similar t...
متن کاملTrace Element Geochemistry of Peridotites from the Izu - Bonin - Mariana Forearc , Leg 125
Trace element analyses (first-series transition elements, Ti, Rb, Sr, Zr, Y, Nb, and REE) were carried out on whole rocks and minerals from 10 peridotite samples from both Conical Seamount in the Mariana forearc and Torishima Forearc Seamount in the Izu-Bonin forearc using a combination of XRF, ID-MS, ICP-MS, and ion microprobe. The concentrations of incompatible trace elements are generally lo...
متن کاملAcross-arc geochemical trends in the Izu-Bonin arc: Contributions from the subducting slab
[1] Abstract: We propose that across-arc differences in the geochemistry of Izu-Bonin arc magmas are controlled by the addition of fertile-slab fluids to depleted mantle at the volcanic front, and residual-slab fluids to fertile mantle in the back arc without slab melting or contemporaneous back arc spreading. The arc consists of a volcanic front, an extensional zone, and seamount chains (the W...
متن کاملEarly stages in the evolution of Izu–Bonin arc volcanism: New age, chemical, and isotopic constraints
A remarkable record of early arc volcanism in the Izu–Bonin–Mariana (IBM) arc is exposed in and around the Bonin Islands, an uplifted segment of the IBM forearc. New Ar/Ar dating results imply that the boninitic volcanism on Chichijima Island occurred in a brief period during Eocene time, between 46–48 Ma. A slightly younger volcanic succession is identified along the Bonin Ridge, including 44....
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ژورنال
عنوان ژورنال: Геотектоника
سال: 2019
ISSN: 0016-853X
DOI: 10.31857/s0016-853x2019127-43