Subduction Initiation and Ophiolite Crust: New Insights from IODP Drilling

Document Type

Article

Publication Date

2017

Keywords

zu, bonin, boninite, basalt, drilling, International Ocean Discovery Program, Expedition 352, Site U1439, Site U1440, Site U1441, Site U1442, ophiolite, subduction initiation, Philippine plate

Digital Object Identifier (DOI)

https://doi.org/10.1080/00206814.2016.1276482

Abstract

International Ocean Discovery Program (IODP) Expedition 352 recovered a high-fidelity record of volcanism related to subduction initiation in the Bonin fore-arc. Two sites (U1440 and U1441) located in deep water nearer to the trench recovered basalts and related rocks; two sites (U1439 and U1442) located in shallower water further from the trench recovered boninites and related rocks. Drilling in both areas ended in dolerites inferred to be sheeted intrusive rocks. The basalts apparently erupted immediately after subduction initiation and have compositions similar to those of the most depleted basalts generated by rapid sea-floor spreading at mid-ocean ridges, with little or no slab input. Subsequent melting to generate boninites involved more depleted mantle and hotter and deeper subducted components as subduction progressed and volcanism migrated away from the trench. This volcanic sequence is akin to that recorded by many ophiolites, supporting a direct link between subduction initiation, fore-arc spreading, and ophiolite genesis.

Comments

Complete list of authors: Timothy Chapman, Gail L. Christeson, Eric C. Ferré, Marguerite Godard, Daniel E. Heaton, Maria Kirchenbaur, Walter Kurz, Steffen Kutterolf, Hongyan Li, Yibing Li, Katsuyoshi Michibayashi, Sally Morgan, Wendy R. Nelson, Julie Prytulak, Marie Python, Alastair H.F. Robertson, William W. Sager, Tetsuya Sakuyama, John W. Shervais, Kenji Shimizu and Scott A. Whattam

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

International Geology Review, v. 59, issue 11, p. 1439-1450

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