DESERTS. a7 
merge into the great valley-floor. It is essentially a valley of deep loess accumu- 
lation, a grassy settling ground of dust blown up from the Kizil Kum. On the 
other hand, its great dust-beds undoubtedly alternate in depth with the flood- 
plain deposits of its cross-streams. Out of ten days, during seven there was a 

Fig. 449.—Silk Factory in Karategin. 
yellow haze, and of these days two were so gloomy that a few hundred yards was 
the range of vision. It is, therefore, a region of still living loess. The kurgans 
and burial mounds left by its more ancient inhabitants are now mantled with 2 
feet or more of loess. 
