basalt to basaltic andesite
Notes on Vent Field Description:
Stoffers et al.: "first observations of high-temperature hydrothermal venting and large sulfide-sulfate chimneys on shallow submarine volcanoes of the Tonga arc." "Two large hydrothermal fields occur on Volcano 19. One is situated near the summit of the central cone between 385 and 540 m water depth. A second is in the western caldera, near the base of the southern wall at a depth of 970 m", "highest temperature vents (245-265 °C) occur at water depths of 385-540 m near the summit of one volcano at 24°S. The vents are spatially related to basaltic dike swarms exposed at a summit cone and in the caldera walls. Clusters of large (to 10 m high) barite, anhydrite, and sulfide chimneys on the summit cone are vigorously discharging clear hydrothermal fluids"
Notes Relevant to Biology:
Stoffers et al.: "A diverse fauna occurs in the vent fields, although the abundance of animals is low compared to MOR vents. Vent crabs (Bythograeidae), vent shrimp (unknown species), and rare polychaete worms (Alvinellidae) occur at the highest temperature vents. Clumps of vent worms (Siboglinidae) and two types of vent associated mussels (live Bathymodiolus and shells of Gigantidas) were found in the shallow pit crater, together with abundant sea stars"; Ju (2013): 2012 ROV ROPOS notable fauna: crab (Austinograea), fish (Symphurus)
Year and How Discovered (if active, visual confirmation is listed first):
2005 with submersibles PISCES IV and PISCES V and ROV RCV-150; 2003 plume and dredge only
Discovery References (text):
Stoffers, P. et al. (2006) Submarine volcanoes and high-temperature hydrothermal venting on the Tonga arc, southwest Pacific. Geology 34: 453-456
(plume only) G. Massoth et al. G3 8, Q11008, doi:10.1029/2007GC001675, 2007, Multiple hydrothermal sources along the south Tonga arc and Valu Fa Ridge
(plume and dredge only) cruise SS02/2003 summary (http://www.marine.csiro.au/nationalfacility/voyagedocs/2003/0203s.htm).
Other References (text):
Arculus "Arc-backarc systems of northern Kermadec-Tonga" (http://www.crownminerals.govt.nz/cms/pdf-library/minerals/conferences-1/045_papers_44.pdf).
Schwarz-Schampera, U., et al. (2007) Cruise Report SONNE 192/2, MANGO, Marine Geoscientific Research on Input and Output in the Tonga-Kermadec Subduction Zone (http://epic.awi.de/21725/1/Sch2010f.pdf)
Ju, Se-Jong (2013) presentation to 37th Annual Conference of the Center for Oceans Law and Policy, May 2013, accessed 31 Oct. 2014: http://www.virginia.edu/colp/pdf/Seoul-Ju.pdf