Alteration type and thermoluminescence ages of altered rocks in the Mutsu-Hiuchidake volcanic field, Shimokita peninsula, NE Japan

Tomiyama, Shingo*; Umeda, Koji; Hanamuro, Takahiro  ; Takashima, Isao*; Hayashi, Shintaro*; Negishi, Yoshimitsu*; Masudome, Yukiko*

To clarify a progress history of the alteration accompanied by Mutsu-Hiuchidake volcanic activities, the study on distribution and characteristics of alteration zones and alteration dating at the Mutsu-Hiuchidake Volcano. The results of alteration zoning and alteration dating suggest that alteration zones generated by hydrothermal activities accompanied by Mutsu-Hiuchidake volcanic activities are distributed along the fracture zones and enlarged by fractures or highly permeable zones in the body of volcano and basement. The result of measurement of homogeneous temperatures of fluid inclusion suggests that the highest temperature of these hydrothermal alterations is about 200 to 250C.