GLACIATION IN SANGRE DE CRISTO RANGE AAT 
ably quite thick. A prospecting tunnel, starting in the moraine 
below the edge of the visible ice, went horizontally in the clear ice 
Fic. 6.—Blanca glacier, looking north. 
for a distance of 115 feet without reaching rock, which, taking into 
account the slope of the surface, demonstrates a vertical thickness of 
