@article{a1e2901181a142db9247c59f35345663,
title = "Influence of Th-rich mineral phases on U–Th radioactive disequilibrium ages of sulfide deposits from the Okinawa Trough",
abstract = "Many samples of hydrothermal sulfide minerals from the Okinawa Trough yield 234U–230Th radioactive disequilibrium ages that are inconsistent with the ages of coexistent barite obtained using electron spin resonance (ESR) method. These results contrast strongly against results obtained for the Southern Mariana Trough, for which the U–Th radioactive disequilibrium ages are roughly consistent with the ESR ages. Sulfide minerals from the Okinawa Trough show large variation in U and Th abundances, suggesting open-system behavior. We infer that the interaction of hydrothermal fluids with thick terrigenous sediment caused large-scale migration of U and Th in the Okinawa Trough. The (234U/230Th) – (232Th/230Th) plots for the sulfide samples from the Hatoma Knoll and the Izena Hole show two mixing trends for each site. The presence of Th-rich phase with high (230Th/234U) ratio seems to cause incorrect age estimates of the sulfide deposits.",
author = "S. Nakai and A. Takamasa and T. Fujiwara and S. Toyoda and J. Ishibashi and R. Yoshizumi and T. Urabe",
note = "Funding Information: Hydrothermal deposits used for this study were collected during NT01-05, YK04-05, NT11-15, NT11-20, and NT12-06 cruises. We wish to thank members of the ROV operation teams, the SHINKAI6500 operation team, and the crews of R/V Natsushima and Yokosuka. Drilled cores used for this study were obtained during the TAIGA 11 cruise. We also wish to thank members of the BMS operation team and crew of R/V Hakurei-Maru No. 2. We wish to thank N. Hokanishi for her assistance during laboratory work at ERI, The University of Tokyo. We thank for two anonymous reviewers for their constructive comments, and K. Mezger for editorial handling. The study was partly supported by the TAIGA project, Grant-in-Aid for Scientific Research on innovative Areas ( 20109004 ) funded by the Ministry of Education, Culture, Sports, Science and Technology (MEXT). Publisher Copyright: {\textcopyright} 2018 Elsevier B.V.",
year = "2018",
month = may,
day = "15",
doi = "10.1016/j.chemgeo.2018.04.004",
language = "English",
volume = "486",
pages = "61--72",
journal = "Chemical Geology",
issn = "0009-2541",
publisher = "Elsevier",
}