Japan Geoscience Union Meeting 2018

Presentation information

[EJ] Evening Poster

S (Solid Earth Sciences) » S-RD Resources, Mineral Deposit & Resource Exploration

[S-RD33] Resource Geology

Wed. May 23, 2018 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Tsubasa Otake(Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University), Daisuke Araoka(Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology), Ryohei Takahashi(秋田大学大学院国際資源学研究科, 共同), Tatsuo Nozaki(Research and Development Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology)

[SRD33-P11] A Raman spectroscopic study on sphalerite from seafloor hydrothermal deposit

*Junji Torimoto1, Taisei Fujiwara2, Hidenori Kumagai1, Tatsuo Nozaki1, Ken Takai1, Katsuhiko Suzuki1, Hirofumi Yamamoto1, Hideaki Machiyama1, Fujio Yamamoto1 (1.Japan Agency for Marine-Earth Science and Technology, 2.Okayama University of Science)

Keywords:seafloor hydrothermal deposit, Laser Raman spectroscopy, sphalerite

Sphalerite, zinc sulfide mineral (ZnS), is one of the major constituent minerals of hydrothermal sulfide deposit such as vein type deposit, skarn deposit and volcanogenic massive sulfide (VMS) deposit on land as well as deep-sea hydrothermal sulfide deposit. Since sphalerite contains several mole percent of iron, this mineral formula was sometimes depicted as (Zn,Fe)S. Mole fraction of iron in sphalerite grains obtained from seafloor hydrothermal deposits exhibit a wide variety along with occurrence and sulfur fugacity of hydrothermal fluid.
Iron contents in sphalerite grains are usually measured directly by electron probe micro analyzer (EPMA). Recently, the laser Raman spectroscopy method has been applied to sphalerite grains to estimate their iron contents. Based on the previous data, intensities in the Raman peaks around 300 cm-1, 330 cm-1 and 350 cm-1 change with their iron contents. Sphalerite with low iron contents shows weak two peaks at the Raman spectroscopy around 300 cm-1 and 330 cm-1, whereas high-iron sphalerite grain has conspicuous peak around 350 cm-1.
In the present study, we applied the laser Raman spectroscopy method to modern seafloor hydrothermal sulfide deposit in the Okinawa Trough and Izu-Bonin area to comprehend spectroscopic features of sphalerite and their difference among several hydrothermal sites.