'. ' 



>. 



.'- . \ : 

 * , ; * .- 



- " v- 



* v 



.0 . 2 CM 



2 MILES 



2 KILOMETERS 



BATHYMETRIC (DEPTH) CONTOUR INTERVAL 10 METERS 

 (1 METER = 3.281 FEET) 



3753'N 



GRAIN SIZE 



i |H Very coarse sand 

 . [ 1 Coarse sand 



to ' ' 



I I I Medium sand 



] Fine sand 

 j | | Very find sand 



6 Photographs of sediment 

 samples and correspond- 

 ing collection sites 



Samples and photographs of the 

 sea floor in the Gulf of the Faral- 

 lones collected by the U.S. Geo- 

 logical Survey reveal a variety 

 of substrates, including rock out- 

 crops, gravel, sand, clay, and 

 deposits of broken shells. Some 

 of these different types of sub- 

 strate are found very close to 

 each other, and the boundaries 

 between them are abrupt. In 

 general, surficial sediment on the 

 Continental Slope in the gulf is 

 finer and less varied in compo- 

 sition and texture than that on 

 the Continental Shelf. This map 

 shows sediment size distribution 

 on an area of the shelf to the 

 northeast of the Farallon Islands. 



123 10'W 



37 43' 

 122 55 



Sediment of the Sea Floor 25 



