90 



buried to a depth of one foot, on an average, have lost about 

 157o in organic content. The rate of destruction varies accor- 

 ding to the rate of sedimentation. Thus, when deposition is 

 slow, oxidation can be almost complete-, whereas when sedimen- 

 tation is relatively fast some of the organic matter escapes 

 decomposition and is buried. This, of course, assumes that 

 there is an adequate supply of oxygen and that aerobic con- 

 ditions are present at the sediment"=water interface in both 

 instances. 



Distribution of Organic Material in Santa Monica Bay , 

 The highest values of organic carbon in Santa Monica Bay are 

 found beyond the shelf break and the lowest occur near shore 

 (Fig, 28), There is a general increase in organic carbon with 

 increasing distance from shore and with increasing depth. 

 Exceptions to the offshore increase are at the head of Santa 

 Monica Canyon where the organic carbon is low, and near 

 Hyperion outfall where it is higher than the average in the 

 nearshore region (Fig, 29), There is also a correlation 

 between the organic carbon and submarine topography? the 

 organic carbon being low in regions of elevations and high 

 in depressions such as Redondo Canyon, 



The organic carbon content for 155 samples ranges from 

 0.13 to 2,76%, averaging 0,59 for the shelf and 1.52% for the 

 canyons and basin slope sediments. The overall average for 

 the bay is 0,96%., Emery (1954) reported that the average 

 organic carbon content for the continental shelf sediments 

 off southern California was 0,44%, and 1,56% for the basin 

 and canyon sediments (Table II), These values are similar 



