trends near magmatic heat sources. The sediment-filled southern 

 section of the Gorda Ridge is a setting for hydrothermal 

 mineralization associated with active venting and vent animals at 

 sites localized by the development of volcanic centers. Geologic 

 diversity along the long length of the Mid-Atlantic Ridge and the 

 short length of the Gorda Ridge favors future discoveries that 

 will produce new insights and practical benefits with reference 

 to the thermal regime of the Earth, chemical and thermal controls 

 of the ocean environment, seafloor mineralization, and adaptation 

 of organisms. 



The 1988 DSV Sea Cliff dive series discovered a high- 

 temperature hydrothermal field with black smokers, mineral 

 deposits, and vent biota where predicted ( Rona and Clague, 1986, 

 1989 ) on the east wall of the rift valley of the northern Gorda 

 Ridge in the GR-14 area (Fig. 6; Federal/State Gorda Ridge Task 

 Force Working Group B, 1988). The scientific team that made the 

 dives has proposed the name "Sea Cliff Hydrothermal Field" for 

 this new site. The name reflects the location of the field 

 perched on cliffs between water depths of 2700 and 2800 m about 

 300 m above the floor of the rift valley and also recognizes the 

 Navy submersible Sea Cliff and its complement for their 

 invaluable contribution to the success of the program. 



ACKNOWLEDGMENTS 



NOAA ' s Office of Undersea Research is acknowledged for 

 support of submersible investigations at the Mid-Atlantic Ridge 

 and for participation in the 1987 Undersea Science Symposium. 

 The Gorda Ridge Technical Task Force of the Minerals Management 

 Service is acknowledged for coordination of the cooperative work 

 at the Gorda Ridge and for participation in the 1987 Gorda Ridge 

 Symposium. The U.S. Navy provided outstanding support on the 

 1986 Gorda Ridge Expedition of DSV Sea Cliff . Thanks to the NOAA 

 VENTS Program for funding and the opportunity to investigate the 

 Gorda Ridge. 



LITERATURE CITED 



Abbott, D. 1986. Heat Flow Results from the Gorda Ridge. 



Open-File Rept. 0-86-12. Portland, Oreg., Oregon Department 

 of Geology and Mineral Industries. 10 pp. 



Atwater, T., and J. D. Mudie. 1973. Detailed Near-Bottom 



Geophysical Study of the Gorda Rise. J_^ Geophys . Res . , Vol. 

 78, No. 35, pp. 8665-8686. 



Baker, E. T., G. J. Massoth, R. W. Collier, J. H. Trefrey, D. 

 Kadko, T. A. Nelsen, P. A. Rona, and J. E. Lupton. 1987. 

 Evidence for High-Temperature Hydrothermal Venting on the 

 Gorda Ridge, Northeast Pacific Ocean. Deep-Sea Res . , 

 Vol. 34, No. 8, pp. 1461-1476. 



22 



