Regional Distribution of Co-Rich Ferromanganese Crusts and Evolution of the Seamounts in the Northwestern Pacific

Abstract

Cobalt-rich hydrogenetic ferromanganese crusts in the Pacific seamounts are potential mineral resources for Co, Ni, Pt and REEs. The Northwest (NW) Pacific, in particular, is one of the most promising areas for the ferromanganese crusts. During the six cruises of the Japanese research vessel Hakurei Maru No.2 over the seamounts of the Marshall Islands in 1996, 1998 and 2002, and the Federated States of Micronesia (FSM) in 1997, 1998 and 2005, the patterns of distribution, resource potential and the relationship to geological parameters were found to be characterized by the potentiality for the ferromanganese crusts. In this article, the relationship between crust abundance and diversity in the geological evolution of the seamounts is discussed on the basis of bathymetric, geological, geophysical and environmental data.

Keywords:

• ferromanganese crust
• Marshall islands
• metal resource
• Micronesia
• Northwest Pacific
• seamount

Acknowledgments

The authors thank the staff at the South Pacific Applied Geoscience Commission for their cooperation during shipboard exploration, and thank Dr. James R. Hein for their detailed review of the paper.

Notes

Note: Bs = Basalt, Fcc = Foraminifera calcareous conglomerate, Tb: Tuff breccia, Fls = Foraminifera limestone, Tf: Tuff, Bsp: Basaltic pyroclatics, Ls: Limestoine, Md: Mudstone, Ss: Sandstone, Ph: Phosphate rock, Hy: Hyaroclastite, RMI: Republic of the Marshall Islands, FSM: Federated States of the Micronesia.

*1 = JICA/MMAJ (1999), *2 = JICA/MMAJ (1997), *3 = JICA/MMAJ (1992), *4 = JICA/MMAJ (1998), *5 = Kopper et al. (2003), *6 = unpublished data, *7 = Haggrty and Premoli (1995), *8 = Usui et al. (2011).

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/umgt.