Genetic relationship between post-caldera and caldera-forming magmas from Aso volcano, SW Japan: Constraints from Sr isotope and trace element compositions

作者：Miyoshi Masaya^*; Shibata Tomoyuki; Yoshikawa Masako; Sano Takashi; Shinmura Taro; Hasenaka Toshiaki

来源：Journal of Mineralogical and Petrological Sciences, 2011, 106(2): 114-119.

DOI：10.2465/jmps.101021b

• Post-caldera stage
• Magma genesis
• Aso volcano
• Sr isotope

We analyzed the Sr isotope and trace element compositions of the post-caldera volcanic products of Aso volcano in central Kyushu, with the aim of investigating the genetic relationship between the last caldera-forming (Aso-4) magmas and post-caldera magmas. The Sr-87/Sr-86 ratio of the magmas drastically changed from the homogeneous (0.7041-0.7042) caldera-forming stage to the heterogeneous (0.7040-0.7044) post-caldera stage. In addition, the obtained geochemical data suggested that the Aso-4 magma did not contribute to the origin and compositional evolution of the post-caldera magmas. These observations indicated that the generation of post-caldera magmas was probably independent of the Aso-4 magma.

• 出版日期2011-4