Izu–Bonin–Mariana Arc : IODP JRSO • Expeditions • Izu-Bonin-Mariana Arc Origins

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IODP Publications / Proceedings / Volume 352 Proceedings of the International Ocean Discovery Program Volume 352 Izu-Bonin-Mariana Fore Arc Expedition 352 of the riserless drilling platform Yokohama, Japan, to Keelung, Taiwan Sites U1439–U1442 30 July–29 September 2014 Volume authorship Reagan, M.K., Pearce, J.A., Petronotis, K.E., and the Expedition 352 Scientists

IODP JRSO • Expeditions • Izu-Bonin-Mariana Arc Origins

Middle Eocene boninites were simultaneously generated over a large region during the early history of the Izu–Bonin–Mariana (IBM) arc. However, widespread boninite magmatism is not recognised in younger subduction zones of similar dimensions. This suggests that an additional tectonic or thermal factor influenced the generation of the IBM boninite suite.

• Boninites and tholeiites were affected by fluids and melts from subducted sediments. • Troodos lavas differ geochemically from Izu–Bonin–Mariana fore-arc lavas and lack FAB. • Lavas of the Troodos ophiolite probably formed not during subduction initiation. ABSTRACT This paper focuses on the processes of arc rifting in the context of the volcanic, structural, and sedimentologic evolution of the Izu-Bonin-Mariana arc-trench system. Middle and late IODP Expedition 352 drilled four sites in the Bonin outer forearc, providing a detailed record of lava eruption and dike emplacement during a short-li

Izu-Bonin-Mariana Arc Origins International Ocean Discovery Program Expedition 351 Site: U1438 Dates: 30 May to 30 July 2014 Ports: Yokohama, Japan to Yokohama, Japan Co-chief Scientists: Richard Arculus & Osamu Ishizuka Staff Scientist: Kara Bogus Logging Staff Scientist: Laureen Drab Scientific Participants 695 Full2 Analytical capabilities The Izu arc is the northernmost segment of the Izu-Bonin-Mariana arc in the western Pacific (Fig. 1). The petrogenesis and geochemistry of the Izu arc lavas have been well studied. 1) Determining the nature of the preexisting crust and mantle prior to subduction onset in the middle Eocene, 2) Identifying and modeling the subduction initiation process and initial arc crust formation, 3) Determining the Paleogene compositional evolution of the IBM arc, and 4) Establishing the geophysical properties of the Amami

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 thermal factor influenced the generation 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

Izu-Bonin-Mariana Arc Origins
Seismic Structure of the Izu Arc‐Backarc System
The Seismic Structure of Island Arc Crust
Slab morphology and deformation beneath Izu-Bonin

Distinct zones of seismic heterogeneity along the Izu–Bonin–Mariana arc have been investigated using complimenting regional bulk sound, shear wave spe Tectonics of the Izu-Ogasawara (Bonin)-Mariana (IBM) arc include the subduction process and the initial arc rifting among the three items mentioned above; this is a salient merit of studying this area’s crustal evolution. [3] focusing on geological and geophysical The continental crust occupies only 0.4% of the total mass of 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 40 Ar/ 39 Ar dating results imply that the boninitic volcanism on Chichijima Island occurred in a brief period during Eocene time, between 46–48 Ma.

This chapter contains sections titled: Introduction Nomenclature and Geography Early Studies of the IBM Arc System History of the IBM Arc System Inputs into the Subduction Factory Geophysi

Subduction initiation as recorded in the Izu-Bonin-Mariana forearc

To address these questions, we compiled a dataset from the Izu-Bonin-Mariana (IBM) proto-arc crust (i.e., fore-arc basalts and boninites), the infant arc, and the mature volcanic arc to examine the temporal variations in the compositions and in the sources of slab fluids since subduction inception. We compare physical properties and seismic structure of SSZ crust at the Izu-Bonin-Mariana (IBM) fore arc with oceanic crust drilled at Holes 504B and 1256D to evaluate the similarities of SSZ and oceanic crust. Expedition 352 basement consists of fore-arc basalt (FAB) and boninite lavas and dikes.

Heavy magnesium isotopic compositions of basalts erupted during arc inception: Implications for the mantle source underlying the nascent Izu-Bonin-Mariana arc The magmatic character of early subduction zone and arc development is unlike mature systems. Low-Ti-K tholeiitic basalts and boninites dominate the early Izu-Bonin-Mariana (IBM) system. Basalts The Izu-Bonin intra-oceanic arc with 20–35 km thick continental crust is being subducted under the Honshu, presumably since 17 Ma. Tomographic image clearly demonstrates that the whole Izu-Bonin arc is subducting under the Honshu arc. Geologic cross section and the thickness of continental crust do not support the accretion of thick crust in spite of the

The IODP Expedition 352 Preliminary Report details findings and research from the expedition, contributing to the study of subseafloor geology. The IBM (Izu-Bonin-Mariana) Arc System is an excellent example of a convergent plate margin. It is 2500 km long convergent margin that extends south from Tokyo, Japan, to Guam, U.S.A. .

The Izu-Bonin-Mariana arc system (Fig. 1) is perhaps the “type” intra-oceanic system, partly as a result of extensive Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) drilling/coring that addressed major subduction-related processes, such as the origin and nature of backarc and forearc basins. Poor recovery on DSDP legs in the Mariana

The southernmost Izu–Bonin arc and northernmost Mariana arc are characterized by K-rich and shoshonitic lavas, referred to as the alkalic volcano province (AVP). These compositions Early Studies are unusual for intra-oceanic arcs and the interpretation of the AVP is controversial. Rifting to form the Mariana Trough back-arc basin occurs just south of the AVP although back

国际地球化学期刊Geochimica et Cosmochimica Acta发表了中国科学院海洋研究所孙卫东研究团队的最新成果：Heavy magnesium isotopic compositions of basalts erupted during arc inception: Implications for the mantle source underlying the nascent Izu-Bonin-Mariana arc。 The report discusses findings from IODP Expedition 351, focusing on geological and geophysical studies Bonin Mariana in the Amami Sankaku Basin. Here, the Izu–Bonin–Mariana (IBM) subduction zone is taken as a case study region. The estimated time-averaged IACGR along the IBM arc changes between 16 and 59 km 3 km −1 Myr −1, with a mean value of 40 km 3 km −1 Myr −1, and this result matches the findings of previous studies well.

IODP Expedition 351 Preliminary Report

The Izu-Bonin-Mariana (IBM) arc system stretches over 2800 km from near Tokyo, Japan to the south of Guam, USA, and is a typical intraoceanic arc system with negligible inputs from sub-arc oceanic

HIMU-type seamounts may be subducted elsewhere beneath the Mariana arc, but obvious HIMU-type components appear only in the initial stages of arc rifting due to the low melting degree and being Izu-Bonin-Mariana Arc OriginsForeword The International Ocean Discovery Program (IODP) represents a renewal and strategic refocusing of what has been widely hailed as one of the most successful and ambitious international scientific programs in the world. Based solidly on the 45-year scientific legacy of the Deep Sea Drilling Project, Ocean Drilling Program, and Integrated 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 fl

The objectives for Expedition 352 were to drill through the entire volcanic sequence of the Bonin fore arc to 1. Obtain a high-fidelity record of magmatic evolution during subduction initiation

Miller, M., Kennett, B. & Lister, G. Imaging changes in morphology geometry, and physical The IBM Izu Bonin properties of the subducting Pacific plate along the Izu–Bonin–Mariana arc.

The magmatic history of the early Izu-Bonin-Mariana (IBM) arc forms a gap between a growing understanding of Eocene subduction and IBM arc initiation in the western Pacific, and Miocene- recent IBM arc processes. Fresh volcanic minerals in lapilli tuffs drilled at DSDP Site 296 on the northern Kyushu Palau Ridge (KPR) provide an opportunity to The Izu–Bonin forearc is characterized by well‐developed submarine canyons but lacks active serpentinite mud volcanoes, while the Mariana forearc has active serpentinite mud volcanoes but lacks submarine canyons. The frontal arc is developed discontinuously, for The magmatic progression produced during the initiation of the Izu-Bonin-Marianas subduction zone took place rapidly over 1 million years, but it has been unclear why. Here, using numerical models

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