Basalt derived from highly refractory mantle sources during early Izu-Bonin-Mariana arc development
نویسندگان
چکیده
Abstract The magmatic character of early subduction zone and arc development is unlike mature systems. Low-Ti-K tholeiitic basalts boninites dominate the Izu-Bonin-Mariana (IBM) system. Basalts recovered from Amami Sankaku Basin (ASB), underlying located west IBM’s oldest remnant arc, erupted at ~49 Ma. This was 3 million years after inception (51-52 Ma) represented by forearc basalt (FAB), tipping point between FAB-boninite typical magmatism. We show ASB are low-Ti-K, aluminous spinel-bearing tholeiites, distinct compared to mid-ocean ridge (MOR), backarc basin, island or ocean basalts. Their upper mantle source hot, reduced, refractory peridotite, indicating prior melt extraction. transferred rapidly pressures (~0.7-2 GPa) plagioclase-spinel peridotite facies boundary surface. Vestiges a polybaric-polythermal mineralogy preserved in this basalt, were not obliterated during persistent recharge-mix-tap-fractionate regimes MOR arcs.
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 ...
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 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 کاملFukutoku-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 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 کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature Communications
سال: 2021
ISSN: ['2041-1723']
DOI: https://doi.org/10.1038/s41467-021-21980-0