Haworth. | 
Geology of Lead and Zine Ores. 
59 
GENERAL GEOLOGICAL SECTION OF THE OZARK REGION. 
Classification of 
AGE. Missouri section. Arkansas section. 
rocks. 
. Represented in southeastern | Represented in eastern Ar- 
Tertiary. Missouri. kansas. 
Upper Car- Cherokee shales, Haworth. 2 tks : 3 
boniferous. | Graydon shales, Shepard. Millstone grit. Undifferentiated 
SER ya ee oe ee shales and sand- 
Chester. i ‘ : stones of the 
St. Louis. | Mississippi river Bonen Bae Se Carboniferous 
2 Warsaw. section. Z system. 
us iecrsaligelle | shale of Arkansas survey. 
2 SE EH SN NR 
a ; Boone chert and limestone, in- | Limestones of the 
Oo ’ 
se Vinee Bere eon nonshard: cluding the St. Joe lime- Mississippian 
5 EO, p P stone of Arkansas survey. series. 
2 
a Pierson limestone, Weller. 
Si Northview shales and sand- 
D stone, Weller. Black shal f th 
B Sac limestone, Weller. een Gas M 
| boniferous sys- 
Sylamore sandstone and tem. 
Eureka shale. Eureka shale of Arkansas 
survey. 
Upper Silu- Hither not represented or not | St. Clair limestone, Williams. 
rian. 
differentiated. 
Trenton. 
Hudson river. 
Roubidoux sandstone, Nason. 
Gasconade sandstone, Nason. 
Lower limits not given. 
Lesueur limestone, Keyes. 
Fredericktown limestone, 
Cason shale, Williams. 
Polk Bayou limestone, Izard 
limestone, saccharoidal 
sandstone, magnesian lime- 
‘stone, cherts, ete., of Arkan- 
sas survey. 
Either not represented or not 
Limestones and 
sandstones of 
the Cambro- 
Silurian system. 
Keyes. differentiated. 
La Motte sandstone, Keyes. 
Lower Silurian or 
Ordovician 
Pre-Cambrian 
erystallines. 
Iron Mountain porphyry. 
Archzean. Knob Lick granite. 
Not represented. 
ble that the entire Mississippian formations are thicker at 
present along the western limit of their exposure than far- 
ther east, where recent erosion has had greater opportunity 
to act upon them. Consequently the surface at Galena may 
be looked upon as the uppermost part of the Mississippian, 
and also the upper surface of the Mississippian now covered 
with the Coal Measures possibly is even younger. 
The records of deep wells to the west of Galena become im- 
portant in this connection, as they show us what kind of 
material can be found underlying the Coal Measures. For 
this purpose there are here included the records of a number 
of wells: One at Cherokee, Kan., figure 1, plate XIX, 908 
feet deep, which struck the top of the Mississippian limestone 
at 352 feet and, therefore, went 556 feet below its surface; 
one at Stone City, figure 1, plate XVIII, a few miles south- 
west of Cherokee, with a total depth of 856 feet, which 
struck the top of the Mississippian at 376 feet and, therefore, 
