[A-HW35] [EJ] Isotope Hydrology 2017

[AHW35-06] A possibility of annually-laminated tufa δ¹³C record as a reflection of volcanic activity

★Invited papers

*Nagayoshi Katsuta¹, Osamu Abe², ATSUSHI YASUDA³, Sayuri Naito¹, Maki Morimoto¹, Takuma Murakami², Shin-ichi Kawakami⁴ (1.Faculty of Education, Gifu University, 2.Graduate School of Enrionmental Studies, Nagoya University, 3.Earthquake Research Institute, University of Tokyo, 4.Faculty of Education, Gifu Shotoku Gakuen University)

Keywords:Tufa, δ13C, δ18O

Mt. Asama, central Japan, is one of the most active volcano in the Japanese Archipelago, and many springs are distributed in the mountain body and its surrounding areas. The river from Nogori springs (R. Nigori) studied in this work is located in the southern part of the mountain, the spring water of which contains the high concentrations of carbonic acid and iron with 5.7 of pH. From the riverbed and the terrace, we found the carbonate-rich deposits with the annually-lamination (thereafter called tufa) which are formed during the CO₂ degassing after flowing out of the springs. In this talk, we present results of the δ¹³C and δ¹⁸O in R. Nogori and the tufa deposits, and then discuss the possibility of tufa δ¹³C record as a reflection of volcanic activity.