PMS, polymetallic massive sulfides
Notes on Vent Field Description:
small vent fields with active sulfide deposits and hydrothermal Fe-Mn oxide crusts on the wall of axial valley; high temperature, clear fluids; 1996 eruption and event plumes close to vent field; NOAA Vents Program webpage for northern Gorda Ridge: http://www.pmel.noaa.gov/vents/gorda_site.html
Notes Relevant to Biology:
tubeworms (Ridgeia), alvinellid worms (Paralvinella)
Year and How Discovered (if active, visual confirmation is listed first):
1988 submersible Sea Cliff; 1985 plume only; 1986 dredge and camera tow did not confirm activity
Discovery References (text):
(submersible Sea Cliff) Rona et al., Geology 18, 493-496, 1990, Major off-axis hydrothermal activity on the northern Gorda Ridge
(plume only) Baker et al., Deep Sea Res. 34, 1461-1476, 1987, Evidence for high-temperature hydrothermal venting on the Gorda Ridge, northeast Pacific Ocean
(dredge and camera tow did not visually confirm activity) Howard and Fisk (1988) Hydrothermal alumina-rich clays and boehmite on the Gorda Ridge. Geochimica et Cosmochimica Acta 52: 2269-2279
(dredge and camera tow did not visually confirm activity) Rona & Clague (1989) Geologic controls of hydrothermal discharge on the northern Gorda Ridge. Geology 17: 1097-1101.
Other References (text):
Cowen and Baker, Deep Sea Research II, 45 (12): 2503-2511, 1998 (special volume), The 1996 Gorda Ridge event detection and response activities: historical perspective and future implications
McClain et al. (2001) Detailed Observations and Sampling of the Sea Cliff Hydrothermal Field (GR-14) on the Northern Gorda Ridge. AGU Fall Meeting abstract #OS41A-0448.