Host Rock:
IAB, BABB, low-K andesite
Deposit Type:
PMS, polymetallic massive sulfides
Notes on Vent Field Description:
E of back-arc spreading center and W of southern Mariana Arc; Gamo et al. suggest this is arc-type not back-arc type like Alice Springs; Hannington et al. (2005) list as arc-backarc volcano; approx. 9 miles/17 km E of spreading axis; small vent field with active sulfide-bearing chimneys on seamount near spreading center, clear smokers, >200 deg C with high pH and alkalinity, barite silicate chimneys
Notes Relevant to Biology:
hairy gastropods, shrimp, brachyuran crabs, barnacles, polychaetes, limpets (differ from further north in the Mariana Arc); NOAA cruise report 2006 also suggests fauna differs from Seamount X just 10km away-- i.e. more diversity like back-arc spreading center vs. frontal volcanic arc; Kojima (2002) review says fauna similar between Forecast and Alice Springs
Year and How Discovered (if active, visual confirmation is listed first):
1992 submersible Shinkai 6500
Discovery References (text):
Gamo, T. et al. (1993) Revisits to the mid-Mariana Trough Hydrothermal Site and discovery of new venting in the southern Mariana Region by the Japanese submersible Shinkai 6500. InterRidge News 2(1): 11-14
Johnson, L., et al. (1993) Hydrothermal deposits and two magma sources for volcanoes near 13°20'N in the Mariana backarc: a view from Shinkai 6500. EOS Trans. AGU Fall Meet. Suppl. 74: 681
Gamo, T. et al. (1994) Mariana 1992 Diving Surveys by "Shinkai 6500" JAMSTEC J. Deep-Sea Res. 10: 153-162 (in Japanese with English abstract).
Other References (text):
[Hein et al., in Geology and Resource Potential of the Continental Margin of Western North America and Adjacent Ocean Basins, 753-771, 1987]
Fryer, in Backarc Basins: Tectonics and Magmatism, 237-279, 1995
S. Kojima et al. (2001) Phylogeny of Hydrothermal-Vent–Endemic Gastropods Alviniconcha spp. from the Western Pacific Revealed by Mitochondrial DNA Sequences. Biol Bull. 200: 298-304
Kojima (2002) Deep-Sea Chemoautosynthesis-Based Communities in the Northwestern Pacific. Journal of Oceanography 58: 343-363.