Magmatic Response to Subduction Initiation: Part 1. Fore-arc Basalts of the Izu-Bonin Arc From IODP Expedition 352.

ABSTRACT: The Izu-Bonin-Mariana (IBM) fore arc preserves igneous rock assemblages that formed during subduction initiation circa 52 Ma. International Ocean Discovery Program (IODP) Expedition 352 cored four sites in the fore arc near the Ogasawara Plateau in order to document the magmatic response to subduction initiation and the physical, petrologic, and chemical stratigraphy of a nascent subduction zone. Two of these sites (U1440 and U1441) are underlain by fore-arc basalt (FAB). FABs have mid-ocean ridge basalt (MORB)-like compositions, however, FAB are consistently lower in the high-field strength elements (TiO₂, P₂O₅, Zr) and Ni compared to MORB, with Na₂O at the low end of the MORB field and FeO* at the high end. Almost all FABs are light rare earth

SUBMITTER: Shervais JW 

PROVIDER: S-EPMC6392113 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature