10,000 



1,000 



Cross Rock 



O 



>- 



a 

 6 



o 



a. 



\ Iron 



: 1i 



100 



,-i-f 





Manganese T ^J- 



10 



C, Zinc 



■i---''i' 



--*. 



■i 



^^-K^^'K 



1 — - 



-r 



E'l- .1/^ '^ 



vjA 



I 1 



J L 



NOV. 



1966 



JAN, 



1967 



MAR. MAY 



JULY 



SEPT, NOV, 



Figure 15.— Concentrations of Iron, manganese, and zinc in sediment collected monthly from the Cross Rock station 

 (salinity range, 5-25 p.p.t.) In the Newport River estuary. Each value represents the mean and standard deviation of 

 10 samples. 



30 



