SECT. 1] 



THE OCEANS AS A CHEMICAL SYSTEM 



Table I (continued) 



Element 



Abundance, 



mg/1. 



Principal species 



Residence time, 

 years 



2.1 x 10 6 

 5.0 x 105 



5.0x105 

 3.5 x 105 



4.0 x 10 4 

 8.4 x 10 4 



1.1 xlO 4 

 6.1 x 103 



1.0 x 103 



5.6 x 10 5 

 4.2 x 10 4 



2.0x103 

 4.5 x 105 



3.5 x 10 2 

 5.0 x 105 



