552 



BIOLOGY OF THE SEAS OF THE U.S.S.R. 



Fig. 263a. Distribution of surface Fig. 263b. Distribution of surface salinity of 



salinity (% ) of the Caspian Sea in the northern Caspian Sea in June 1934 (% ) 

 February and March 1934 (Brujevitch, (Ivanov). 



1950). 



The difference in the salt ratio of Caspian and ocean waters {Table 227), 

 which appeared as a result of the separation of the Caspian Sea from the ocean 

 and which is gradually rising owing to the metamorphism by river discharge, 

 makes it possible to calculate the approximate period of time of the existence 

 of the 'lake' phase of the Caspian Sea. S. Brujevitch (1939) has calculated it in 



Table 228 



