Deposit Type:
LTH, vein and diseminated sulfides in altered lavas, Mn crusts
Notes on Vent Field Description:
on Shichito-Iwojima Ridge; vein and disseminated pyrite with minor polymetallic sulfides in altered andesite lavas, Mn crusts on flanks of volcano, low temperature (22 C) clear venting, sulfide mineralization, hydrothermal oxide deposits; Urabe et al. (1987): "This is, to our knowledge, the first discovery of hydrothermal precious and basemetal mineralizations associated with front volcanism in the marine environment."; Neptune Minerals Plc, 21 Feb. 2007, applications by Neptune Minerals Japan Kabushiki Kaisha: "Neptune's applications also cover the Myojin and Myojinsho Knolls, and the Suiyo and Kaikata Seamounts, all of which contain known SMS mineralisation."
Notes Relevant to Biology:
Bythograeidae, Mytilidae, Polynoidae, gastropods, barnacles, tonguefish
Year and How Discovered (if active, visual confirmation is listed first):
1988 submersible Shinkai 2000; 1985 dredge only
Discovery References (text):
[Mitsuzawa et al. (1989) Measurements of water temperature and current around the submarine caldera in the KC Kaikata Seamount. JAMSTEC Deep Sea Res. 5: 47-55 (in Japanese with English abstract)]
(dredge only) Urabe, T et al. (1987) Hydrothermal sulfides from a submarine caldera in the Shichito-Iwojima Ridge, northwestern Pacific. Mar Geol 74: 295-299.
Other References (text):
Usui & Nishimura, Submersible observations of hydrothermal manganese deposits on the Kaikata Seamount, Izu-Ogasawara (Bonin) Arc, Mar. Geol., 106, 203-216, 1992.