SECT. 3] 



BASIN SEDIMENTATION AND DIAGENESIS 



601 



surface zone, thus allowing a greater net loss of nitrogen than in Santa Barbara 

 Basin where the absence of an oxidized zone makes this cycle impossible. 



The California basin waters contain small quantities of oxygen and this 

 appears to be enough to allow the oxidation of any ammonia which may escape 

 from the sediment. The result is that the basin waters have no detectable 

 nitrite or ammonia but contain about 40 \ig atoms/1, of nitrate (a little less for 



10 100 1000 



CUMULATIVE /uq NITROGEN/GRAM OF 

 DRY SEDIMENT 



10,000 



Fig. 4. Depth distribution of nitrogen compoimds in sediments of three southern CaUfornia 

 basins. Note the use of a logarithmic scale of concentration. (From Rittenberg, 

 Emery and Orr, 1955, fig. 4.) 



the bottom waters of the reducing basins and more for the oxidizing basins), 

 which is considerably lower than the 240 [j.g atoms/1, present in the surface 

 interstitial water of Santa Catalina Basin. 



In contrast to nitrogen, phosphorus is supplied to basin sediments largely as 

 detrital phosphate minerals (e.g. apatite) and phosphate adsorbed on hydroly- 

 zates and oxidates (e.g. clays and ferric hydroxide) in addition to organic 

 phosphate. The conversion of organic phosphorus to phosphate occurs with 



