U S. GEOLOGICAL SURVEY 
BULLETIN NO 280 PL. 
GEOLOGIC SKETCH MAP 
OF THS 
IAMPART REGION, 
ALASKA. 
ByL.M.Priivdle and F.L.Heas, 190 
APPROXIMATE Si All 
— — i '£ =- -3 8 
QUATERNARY 
■ 
CRETACEOUS* 

CARBONIFEROUS 
PRE-OEV0NIAN 
