Journal article
Early stages in the evolution of Izu–Bonin arc volcanism: New age, chemical, and isotopic constraints
Earth and planetary science letters, Vol.250(1-2), pp.385-401
2006
DOI: 10.1016/j.epsl.2006.08.007
Abstract
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
40Ar/
39Ar 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 44.74
±
0.23 Ma high-Mg andesite from the Mikazukiyama Formation, the youngest volcanic sequence on Chichijima, 44.0
±
0.3 Ma tholeiitic to calcalkaline andesite from Hahajima Island, and 3 samples of andesite collected by the submersible SHINKAI 6500 from the Bonin Ridge Escarpment (BRE) that range in age from 41.84
±
0.14 to 43.88
±
0.21 Ma. Four SHINKAI 6500 dives (YK 04–05) on the BRE mapped an elongated constructional volcanic ridge atop the escarpment; we observed steeply west-dipping volcaniclastic debris flows shed from the summit of this ridge into the Ogasawara Trough to the west. These dives recovered fresh andesitic clasts from debris flows along the northern segment of the ridge, and high-Mg andesite lava blocks and Nummulitic limestone of middle Eocene age from the escarpment northwest of Chichijima. Our results also confirm previous inferences that melting of depleted mantle at shallow levels beneath the length of the arc with the aid of hydrous fluids from newly subducted slab to produce boninitic volcanism occurred nearly simultaneously along the entire length of the IBM arc system during the earliest stage of arc evolution. BRE–Mikazukiyama Formation–Hahajima andesites represent a transitional stage from forearc spreading (represented by ODP site 786-Chichijima boninites) and the stable, mature arc that developed in the Oligocene. These OPX-bearing high-Mg or tholeiitic to calcalkaline andesites were erupted along the BRE, as the arc magmatic axis localized and retreated from the trench.
Details
- Title: Subtitle
- Early stages in the evolution of Izu–Bonin arc volcanism: New age, chemical, and isotopic constraints
- Creators
- Osamu Ishizuka - National Institute of Advanced Industrial Science and TechnologyJun-Ichi Kimura - Shimane UniversityYi B Li - The University of TokyoRobert J Stern - The University of Texas at DallasMark K Reagan - University of Iowa, Earth and Environmental SciencesRex N Taylor - National Oceanography Centre, Southampton, European Way, Southampton, SO14 3ZH, UKYasuhiko Ohara - Japan Agency for Marine-Earth Science and TechnologySherman H Bloomer - Department of Geoscience, Oregon State University, Corvallis, OR, 97331, USATeruaki Ishii - Geological InstituteUlysses S Hargrove - Geoscience Department, University of Texas at Dallas, Box 830688, Richardson TX 75083-0688, USASatoru Haraguchi - Ocean Research Institute, University of Tokyo, 1-15-1, Minamidai, Nakano-ku, Tokyo 164-8639, Japan
- Resource Type
- Journal article
- Publication Details
- Earth and planetary science letters, Vol.250(1-2), pp.385-401
- Publisher
- Elsevier B.V
- DOI
- 10.1016/j.epsl.2006.08.007
- ISSN
- 0012-821X
- eISSN
- 1385-013X
- Language
- English
- Date published
- 2006
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9983557797802771
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