THE ARAL SEA 



649 



Bottom topography 



The greatest depth (67 m) occurs near the western shore of the Sea (Fig. 303) ; 

 the predominant depths are 10 to 30 m, with an average depth of 16-2 m. 



The Aral Sea is divided into two basins by a submarine ridge with a system 

 of islands stretching from north to south : the smaller, but deeper, western 

 basin and the eastern one which does not exceed 30 m in depth. 



The northern part, separated from the rest of the Sea by the Kuch-Aral 

 island, is called the Maloe More. 



^r-~-j\ SANDY SILT 

 fc'VyVH^ COARSE SAND AVERAGE hZ-Z-ZH SILTY SAND OOZE 



|:. : :У:-У-.-;| FINE SAND | | CLAY AND MUD 



НПППМЩ DEPOSITS WITH MORE 

 11 1 1 11 1 111 1 11 THAN 40% LIME 



Fig. 304. Distribution of the soils of the Aral sea-bed 

 (Kulichenko, 1944). 



Soils 



Grey mud covered by a thin brown layer is the predominant bed of the Aral 



Sea (Fig. 304). Black mud, owing its colour to the presence of a colloidal 



ferrous hydroxide, is found in the western deeper part of the Sea and in some 



inlets. 



Freshly brought up black mud usually smells of hydrogen sulphide. Huge 

 masses of rotting filamentous algae, forming a complete felt-like cover over 



