SHEET No. 19 
114°30' 
m 
a 
CL bya RD 
° é 25 30MILES a 
GLACIAL LAKE MISSOULA, HEMMED IN BY A BARRIER OF ICE 
ON THE NORTH 
cs OME wy Ba isi Fee Sp Tak 
boned 
3 
ANT! 
mort 
NOISSIIN 
‘\ Lvragph ); 
\ ee ae wate Hoy, 
; ’ sa pk, Ninenileg@n (lS htown 
Stream deposits (alluvium), Rivuler WS Be OPTED ce Shire, i wi OR owns 
giacial drift, and sediment SSE fae i at, 4 oe, 
eposited in glacial Lake Quaternary S Cyr s <8 Xe o 
Missoula ) SESS Sy SS 
Glacia! moraine . / + ' 
Clay, volcanic ash, and sand en 
(lake beds) 3,000 Tertiary S 
Red sandstone and shale =o 
Spokane formation) 3,800 i = 
Impure limestone (Newland) 4,800 & 
Q rtoit vA chal A 
(Ravalli quartzite) 2,500 ea yn 
Bluish-quartzite and shale Algonkian 
(Prichard formation) 8,000 f (Belt series) 
In places formations D, F, 
, and H, have not been 
separated an entire 
mass is called simply 1 
Belt series / Scale 500,000 
Diorite, intrusive Approximately 8 miles to | inch 10 TRAM FO 
betel pa Cree 
TY Re, SEE SA, MRM. cs Cee ous 
if. s+ » § © BS wiles “TO 
Contour interval 200 feet 
Se oe es ai oe * 
aorta gh ‘ Mt ea - . 2 
| The crossties on the railroads are spaced | mile apart ww 
ns° 116"a0" 
ENGRAVED AND PRINTED BY THE U.S GEciacica: Sum 
