WASH. 



42 



130* 



128' 



126* 



24 c 



Figure 1. Location map of Oregon continental margin (shelf and 

 slope), Juan de Fuca plate (Cascadia Basin), and spreading 

 Juan de Fuca and Gorda ridges. Subduction zone (saw teeth 

 on upper plate) located on the continental slope. Location 

 of Deep Sea Drilling site 174 on Astoria Fan shown by solid 

 dot. Alvin dive area (labeled dives) is shown by the black 

 box. Study area is shown as lined box (see also fig. 2). 

 (After Schroeder et al. 1987). 



153 



