Melting of dehydrated oceanic crust from the stagnant slab and of the hydrated mantle transition zone: Constraints from Cenozoic alkaline basalts in eastern China

Tetsuya Sakuyama, Wei Tian, Jun Ichi Kimura, Yoshio Fukao, Yuka Hirahara, Toshiro Takahashi, Ryoko Senda, Qing Chang, Takashi Miyazaki, Masayuki Obayashi, Hiroshi Kawabata, Yoshiyuki Tatsumi

Research output: Contribution to journalArticle

86 Citations (Scopus)

Abstract

The feasibility of oceanic igneous crust melting in stagnant slabs has previously been proposed from experimental petrological research. However, geochemical evidence for such melting has not yet been found from igneous rocks. We present evidence to suggest that melts from the igneous layer in the stagnant Pacific slab contributed to the source composition of basalts erupted in eastern China. Fe-rich (> 13 wt%), Si-poor (< 43 wt%) basalts occur only above the leading edge of the stagnant Pacific slab in eastern China, ~. 2000. km west of the Pacific Plate trench. The source of these basalts has Nd-Hf and Sr-Nd-Pb isotopic compositions akin to those of the igneous layer in the Pacific slab, and their extremely low Rb and Pb contents suggest that their source material was modified by subduction processes. Together with forward modeling calculation on trace elements and isotope compositions, these geochemical characteristics imply that they received a contribution from fluid released from hydrated transition zone and dehydrated carbonate-bearing oceanic crust in the stagnant slab, without a long time-integrated ingrowth of Sr-Nd-Hf-Pb isotope systems, almost at the leading edge of the stagnant Pacific slab.

Original languageEnglish
Pages (from-to)32-48
Number of pages17
JournalChemical Geology
Volume359
DOIs
Publication statusPublished - Nov 14 2013
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Geology
  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'Melting of dehydrated oceanic crust from the stagnant slab and of the hydrated mantle transition zone: Constraints from Cenozoic alkaline basalts in eastern China'. Together they form a unique fingerprint.

  • Cite this

    Sakuyama, T., Tian, W., Kimura, J. I., Fukao, Y., Hirahara, Y., Takahashi, T., Senda, R., Chang, Q., Miyazaki, T., Obayashi, M., Kawabata, H., & Tatsumi, Y. (2013). Melting of dehydrated oceanic crust from the stagnant slab and of the hydrated mantle transition zone: Constraints from Cenozoic alkaline basalts in eastern China. Chemical Geology, 359, 32-48. https://doi.org/10.1016/j.chemgeo.2013.09.012