Sr-Nd-Pb isotopic and major and trace element compositions of the Yufu-Tsurumi volcanic rocks: implications for the magma genesis of the Yufu-Tsurumi volcanoes, northeast Kyushu, Japan

• SUGIMOTO Takeshi

  Beppu Geothermal Research Laboratory, Institute for Geothermal Sciences, Kyoto University

• SHIBATA Tomoyuki

  Beppu Geothermal Research Laboratory, Institute for Geothermal Sciences, Kyoto University

• YOSHIKAWA Masako

  Beppu Geothermal Research Laboratory, Institute for Geothermal Sciences, Kyoto University

• TAKEMURA Keiji

  Beppu Geothermal Research Laboratory, Institute for Geothermal Sciences, Kyoto University

Bibliographic Information

Other Title

• Sr–Nd–Pb isotopic and trace element compositions of the Yufu–Tsurumi volcanic rocks: implications for the magma genesis of the Yufu–Tsurumi volcanoes, Northeast Kyushu, Japan

Abstract

We have characterized the Sr-Nd-Pb isotopes and major and trace element compositions of 10 Quaternary volcanic rocks from the Yufu and Tsurumi volcanoes in northeast Kyushu, Japan. The enriched incompatible elements, negative Nb, and positive Pb and Sr anomalies are generally interpreted to be from island arc affinities of the lavas. However, the LREE/HREE ratio of the lavas (La/Yb = 8.5 ± 1.3) is greater than that from the island arc intermediate volcanics from northeast Japan (La/Yb = 3.8 ± 0.6), suggesting a different origin. One dacite sample had a Sr/Y ratio > 40, and the SiO₂, Al₂O₃, MgO, Y, Yb, Sr, and ⁸⁷Sr/⁸⁶Sr compositions fell within the range of typical adakites. Other lavas were classified as normal island arc-type magmas. These results suggest that a partial melting of the subducting Philippine Sea Plate played a role in the genesis of the Yufu-Tsurumi volcanic rocks. The Sr, Nd, and Pb isotopic compositions show evidence of mixing between melts, derived from oceanic basaltic crust and subducted terrigenous sediments for the adakite magma, whereas another source is required to explain the enrichment in Sr-Nd isotopes and depletion in Pb isotopes of the island arc-type magma. Although the island arc-type magma appears to have a different source, a mixing of the adakite magma with this magma is apparent from our observations of the trace elements and isotopes.

Journal

• Journal of Mineralogical and Petrological Sciences

  Journal of Mineralogical and Petrological Sciences 101 (5), 270-275, 2006

  Japan Association of Mineralogical Sciences

Keywords

• Yufu-Tsurumi volcanoes
• Trace element
• Isotope
• Slab melting
• Adakite
• Philippine Sea Plate
• Sediment component

Details

• CRID: 1390282681522247680
• NII Article ID: 10018106166
• NII Book ID: AA11460926
• DOI: 10.2465/jmps.101.270
• COI: 1:CAS:528:DC%2BD2sXhtVGmsg%3D%3D
• ISSN: 13493825
• ISSN: 13456296
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed