SPI06 



Accretionary Prism ^. 



Site 176 



Nehalem Bank Basin Deposits 



SEC 



KM 



SPI04 



Projected 

 Chimneys 



Figure 3. Line drawing interpretations of Oregon State 



University single channel seismic reflection lines SP-104 

 and -106 showing shelf basin deposits and accretionary 

 prism. Dashed line with open barbs shows thrust boundary 

 between the two features. See figure 2 for location. Drill 

 site 176 and Nehalem Bank are indicated on SP-106. Note 

 projected location of carbonate chimneys over accretionary 

 prism on SP-104. (After Schroeder et al. 1987). 



156 



