Tholeiitic vs Calc-alkalic Differentiation and Evolution of Arc Crust: Constraints from Melting Experiments on a Basalt from the Izu-Bonin-Mariana Arc
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منابع مشابه
Fukutoku-oka-no-ba Volcano: A new perspective on the Alkalic Volcano Province in the Izu±Bonin ± Mariana arc
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 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....
متن کاملThematic Article Noble gases in pillow basalt glasses from the northern Mariana Trough back-arc basin
Noble gas concentrations and isotopic compositions have been measured in eight samples of pillow basalt glasses collected from seven different localities along 250 km of the Mariana Trough spreading and rifting axis. The samples have uniform and mid-ocean ridge basalt (MORB)-like He/He values of 9±12 ́ 10 (6.4±8.6 times atmospheric) despite large variations in He. Concentrations of the noble ga...
متن کاملOrigin 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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ژورنال
عنوان ژورنال: Journal of Petrology
سال: 2009
ISSN: 0022-3530,1460-2415
DOI: 10.1093/petrology/egp044