586 



CYCLES OF ORGANIC AND INORGANIC SUBSTANCES 



influxes of the elements, initiated such calculations, and his data 

 are shown in Table I. An alternate approach has been made upon 

 the basis of the total amount of sedimentation in the marine 

 environment (Goldberg and Arrhenius, 1958), and the residence 

 times so derived also are shown in Table I. A remarkable agree- 

 ment is observed between these sets of data. The only striking 

 discrepancy is found for the case of calcium. The many difficulties 

 in trying to obtain a geochemical balance for this element are well 

 known, and we certainly have not been able to resolve this 

 difficulty, at least within a factor of 8. 



Although many independent assumptions are involved in the 

 calculations, both the absolute and relative values for most of the 

 residence times appear reasonable. Sodium has a residence time 

 within an order of magnitude of the age of the oceans, several 

 billion years. This lack of reactivity is in accord with its aqueous 

 chemistry. The alkali and alkaline earth metals have residence 

 times in the range of 10^ to 10* years. Manganese shows a re- 

 markably low value, 7000 years, especially in ccmip arisen with the 

 metals nickel and zinc, which prcbal ly have similar chemistries 



Table I. Residence Times of Elements in the Oceans 



Element Amount in Oceans, g 



Residence Time, Years 



Goldberg and Arrhenius (1958) Barth (1952) 



Na 



Mg 



Li 



Sr 



K 



Ca 



U 



Zn 



Cu 



Co 



Si 



Pb 



Mn 



Th 



Fe 



Ti 



Al 



2.6 X 10* 



4.5 X 10' 

 2.2 X 10^ 



1.6 X 10^ 

 1.1 X 10^ 

 8.0 X 10^ 

 6.5 X 10* 

 1.8 X 10* 

 6.5 X lO-* 

 1.8 X 10^ 

 1.0 X 10^ 



<1.0 X 10' 



7.0 X 10^ 



<1.4 



10^ 



1.4 X lOi 



X 



1.4 X \0- 



1.6 X 102 



1.0 X 10- 



2.1 X 10* 



2.2 X 10^ 



1.0 X 10^ 

 1.0 X 10« 



3.5 X 10^ 



