U. S. GEOLOGICAL SURVEY 
BULLETIN 845 SHEET 20 
\N. Alkali 
\Flat 
olga 
10830 Arizona-New Mexico 
Ct VY 
i a 
me) 
EXPLANATION 
cist 
4 Limestone 
Sandstone 
G Schist and granite 
| 
> 
| 
3 
H_ Porphyry, ete. (intrusive) 5X2: 
i 
Scale 500,000 
| inch=8 miles (approximately) 
5 10 15 
A Sand and gravel re 
Quaternary 
B Lava (basalt) 30’ 
c_ Lavas and other rocks 800’ Tertiary 
of voleanie origin 
3,000’ Lower C —- 
es 
Sheet 19 
series) 
(Comane 
600’ Cambrian 
Pre-Cambrian 
Post-Cretaceous 
Geology by N. H. Darton and C. J. Sarie A 
20 MILES 
10) 
° 5 10 15 20 KILOMETERS 
Contour interval 200 feet 
The distances from New Orleans, La., are shown every 
10 miles, and the crossti d. T mile a, 
Fach auad L 
topographic map of that name 
= owe 
in the lower left corner is mapped in detail on the HB. C8. 
108 30 
Topography: U. S. Geological Survey quadrangle maps 
WILLIAMS @ HEINTZ CO. WASH. D C. 
oI EE iA TOE OO 
400’ = Devonian 
