[M-GI33] Data-driven geosciences

[MGI33-04] Independent Component Analysis of bulk chemical compositions of submarine hydrothermal deposits in the Okinawa Trough

*Akito Aichi¹, Kazutaka Yasukawa^1,2, Tatsuo Nozaki^3,1,4,2, Yutaro Takaya^5,3,2, Mizuki Ishida¹, Erika Tanaka¹, Kentaro Nakamura¹, Yasuhiro Kato^1,2 (1.School of Engineering, The University of Tokyo, 2.ORCeNG, Chiba Institute of Technology, 3.JAMSTEC, 4.Kobe University, 5.Waseda University)

Keywords:hydrothermal deposits, Okinawa Trough, hydrothermal mineralization, multivariate analysis, independent component analysis

Submarine hydrothermal activity is one of the key processes controlling the transfer of energy and materials from the Earth’s interior to surface systems including hydrosphere and biosphere. It is also an important process that produces mineral deposits of economic interest. In recent years, multiple scientific drilling cruises were conducted in the Okinawa Trough, a back-arc basin with a number of active hydrothermal vents [1-3], using the drilling vessel CHIKYU. The core samples contain various altered/unaltered volcaniclastic and hemipelagic sediments, as well as sulfide minerals. By ICP-QMS analysis, a comprehensive dataset of bulk chemical composition (>1,300 samples x 47 element contents) of the drilling core samples has been constructed.

In this study, we statistically analyzed the huge dataset using independent component analysis (ICA). ICA is a powerful method to recover mutually independent signals from an observed mixture of the source signals and it has been successfully applied to geochemical data [4-6]. We implemented ICA to identify multi-elemental features and their distributions involving geochemical heterogeneities in the (sub)seafloor hydrothermal deposits. In the presentation, through consideration of information of the extracted components, we will discuss the geochemical characteristics of the hydrothermal activities in the study area.


[1] Glasby et al. (2003) Ore. Geol. Rev. 23, 299-339.
[2] Nakajima et al. (2015) PLoS One. 10, e0123095.
[3] Nozaki et al. (2016) Sci. Rep. 6, 22163.
[4] Iwamori & Albarède (2008) Geochem. Geophys. Geosyst. 9, Q04033.
[5] Yasukawa et al. (2016) Sci. Rep. 6, 29603.
[6] Yasukawa et al. (2019) Geochem. Geophys. Geosyst. 20, 3402-3430.