SmlthsoMinn Report, 1050. Black 



Plate 4 



1. Ice-wedge ])olygoiis and ground ice in 15-foot sand bank exposed by wave 

 action on the south side of Admiralty Bay, about 45 miles southeast of 

 Barrow, Alaska. Photograjihed August 28, 1947. 



Ice-wedge polygons of three distinct stages in surficial expression on coastal 

 plain near Barrow, Alaska. Zone 1, containing high-centered polygons, is 

 oldest; zone 2 is intermediate to zone 3, the youngest, with low-centered 

 polygons. Photographed July 20, 1947, by the U. S. Coast and Geodetic 

 Survey. 



