THE WORK OF RUNNING WATER 



95 



enter seas or lakes. Deltas are sometimes built where one stream 

 flows into another, especially where a swift stream with much sedi- 

 ment joins a slow one. 



20 ao 



Fig. 100. The lower end of the Mississippi, showing its distributaries. 

 (C. & G. Surv.) 



Much land has been made by the growth of deltas. Thus the 

 Colorado River has built a great delta many square miles (above 

 water) in area at the head of the Gulf of California (Fig. 104). 

 The delta has been built quite across the former gulf near its upper 

 end, shutting off the head. In the arid climate of the region, this 

 shut-off head became a nearly dry basin, the lowest part of which 



