Evolution of carbon dioxide-bearing saline fluids in the mantle wedge beneath the Northeast Japan arc

Yoshitaka Kumagai, Tatsuhiko Kawamoto, Junji Yamamoto

Research output: Contribution to journalArticlepeer-review

Abstract

Lherzolite xenoliths containing fluid inclusions from the Ichinomegata volcano, located on the rear-arc side of the Northeast Japan arc, may be considered as samples of the uppermost mantle above the melting region in the mantle wedge. Thus, these fluid inclusions provide valuable information on the nature of fluids present in the sub-arc mantle. The inclusions in the Ichinomegata amphibole-bearing spinel–plagioclase lherzolite xenoliths were found to be composed mainly of CO2–H2O–Cl–S fluids. At equilibrium temperature of 920 °C, the fluid inclusions preserve pressures of 0.66–0.78 GPa, which correspond to depths of 23–28 km. The molar fraction of H2O and the salinity of fluid inclusions are 0.18–0.35 and 3.71 ± 0.78 wt% NaCl equivalent, respectively. These fluid inclusions are not believed to be fluids derived directly from the subducting slab, but rather fluids exsolved from sub-arc basaltic magmas that are formed through partial melting of mantle wedge triggered by slab-derived fluids.

Original languageEnglish
Article number1056
Pages (from-to)1-13
Number of pages13
JournalContributions to Mineralogy and Petrology
Volume168
Issue number4
DOIs
Publication statusPublished - Oct 1 2014
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geochemistry and Petrology

Fingerprint

Dive into the research topics of 'Evolution of carbon dioxide-bearing saline fluids in the mantle wedge beneath the Northeast Japan arc'. Together they form a unique fingerprint.

Cite this