U. S. GFOLOGICAL SURVEY 
BULLETIN NO. 217 PL. XVI 
A. WEATHERING OF THIN SHEET OF BASALT ABOVE SOFT STRATA, MULE. OREG. 
11. WEATHERING OF THICK SHEET OF BASALT ABOVE THICK BEDS OF SOFT 
MATERIAL, SNAKE RIVER CANYON, OPPOSITE ENTERPRISE, IDAHO. 
