[SVC47-P19] Chemical composition of minerals and melt inclusions in Kusasenrigahama pumices from Aso volcano, Kyushu, Japan -Comparison with Aso-4-
Keywords:Aso volcano, Melt inclusion, Kusasenrigahama pumice
Results of analysis show that mineral composition of Kusasenrigahama pumice is homogeneous, scale of volcanic activity depends on water concentration, and magma chamber under the Kusasenrigahama pumice cone is lower water concentration and higher temperature, compared with Aso-4.
(a) Uppermost and lowermost layer of Kusasenrigahama pumice shows nearly the same chemical composition of constituent minerals (plagioclase; An# = 64 ~68, clinopyroxene; Mg# = 75 ~ 77, orthopyroxene; Mg# = 72 ~ 74). Clinopyroxene and orthopyroxene is almost the same composition between Kusasenrigahama pumice and Aso-4. On the other hand, plagioclase composition of Kusasenrigahama pumice is different with that of Aso-4.
(b) Water concentration in MI of lowermost layer (A) is higher than that of uppermost layer (D). Compared with Aso-4, MI of Kusasenrigahama pumice contains less water.
(c) Clinopyroxene and liquid thermobarometers shows temperature and pressure, 897 ± 45 ℃, 1.8 kbar respectively. When this pressure is applied, plagioclase and liquid thermometer shows temperature, 888 ± 37 ℃. These temperature is higher than temperature of Aso-4 (810 ~ 850 ℃).