R7: Petrology, Mineralogy and Economic geology (Joint session with SRG)

[R7P-08] Magnetic properties of isocubanite from seafloor hydrothermal deposits in the Okinawa Trough

*Chie Kato¹, Masao Ohno¹, Yoshihiro Kuwahara¹, Tadahiro Hatakeyama², Yasuhiro Yamada³, Shuhei Totsuka⁴, Kazuhiko Shimada⁴, Jun-ichiro Ishibashi⁴, Toshiro Nagase⁵ (1. Kyushu Univ., 2. Okayama Univ. Sci., 3. Tokyo Univ. Sci., 4. Kyushu univ., 5. Tohoku Univ.)

Keywords:isocubanite, low-temperature magnetometry, Mössbauer spectroscopy, seafloor hydrothermal deposits

We conducted low-temperature magnetometry and Mössbauer spectroscopy on isocubanite collected from hydrothermal deposits in the Okinawa Trough, and isocubanite synthesized by heating a cubanite crystal. Samples undergo a magnetic transition at ~100 K, but the magnetization intensity differed by 50 times. The Mössbauer spectra indicate that the ‘synthesized’ isocubanite suffered the effects of disorder, while the spectra of a chimney sample are consistent with those of chalcopyrite and two iron sites in the ‘Cu_1-εFe_3+εS₄’ phase reported by Wintenberger et al. (1994).