U. 8. GEOLOGICAL SURVEY 
BULLETIN 845 SHEET 16 
10530 105° Taal 
3i 7 ° 
30) EXPLANATION sf 
A Sand and gravel (valley fill) 0-700’ Quaternary 
B Lavas and other rocks 1,800’+ Tertiary 
of voleanie origin 
C Shale, limestone and 1.100’ Upper Cretaceous 
sandstone , “i (Gulf series) 
D_ Limestone Washita group I ice 
E Limestone * Fredericksburg group 3,000’ esate ar pa 
F Limestone, sandstone, ete. Trinity group 
G Limestone 1,500’ er’ 
H_ Limestone Montoya on Fl Paso 1,300’ Ordovician 
| Sandstone an Horn -700' Cambrian 
J Sandstone, cherty lime- Millican 3,000’+ Algonkian (?) 
= stone, etc., with diabase sills 
K_  Schist and quartzite & Mountain 77 Algonkian (?) 
L_ Intrusive rocks (not fully ag Post-Cretaceous 
Sheet 17 
En ros 
pion fer 
Scale 500,000 
linch=8 miles (approximately) 
5 ie} i5 
12] 5 
10 15 
Contour interval 200 feet 
le 
miles, and the crossties are drawn 1 mile apart 
Each quadrangle shown on the map with 
in the lower left corner is mapped in detail 
topographic map of that name 
on the U. 8S. 
The distances from New Orleans, La., are shown every 
10 e 
20 KILOMETERS 
ith a name in parentheses 
G. 8. 
20 MILES 
differentiated) 
—-— Fault 
-~- Concealed fault 
Geology by C. L. Baker, G. B 
P. B. King, and N. H. Dart 
f 
ee 
105°30 
105 
. Richardson, 
on 
Topography: U. S. Geological Survey quadrangle maps 
