Ieckel.] Missouri. 223 
Mississippi River area, which is the most promising of the three as a 
lource of cement material, will be discussed last and in greater detail 
than the others. 
In southwestern Missouri the Mississippian limestones form the 
surface of the greater part of McDonald, Newton, Jasper, Barry, 
Lawrence, Stone, Christian, Greene, Dade, and Cedar counties, and 
klso the southwestern half of Polk and smaller portions of Barton, 
Bt. Clair, Hickory, and Benton counties. This extensive limestone 
area is traversed by numerous railroads, but the competition of Kansas 
[plants using natural gas for fuel would probably make a cement plant 
located in southwestern Missouri unsuccessful. 
I Another area of Mississippian limestones is on and near the Missouri 
(River. In this area the limestones cover most of Pettis, Saline, and 
{Cooper counties, on the south side of the river, while they outcrop 
[continuously along the north bank of the river from Miami station, 
Carroll County, through southern Howard County, to below Roche- 
port, Boone Count}'. The limestone belt then leaves Missouri River 
and turns northeastward, through Boone, Callaway, and Montgomery 
counties, to join the Mississippi River limestone belt discussed below. 
A very extensive and important area of Mississippian limestones 
occurs in northeastern and eastern Missouri, along Mississippi River. 
This belt covers the eastern half of Clarke, all, or almost all, of Lewis, 
Knox, Shelb} 7 , Marion, Monroe, Ralls, Pike, Lincoln, and St. Charles 
counties, and portions of Montgomery, Warren, St. Louis, Jefferson, 
Ste. Genevieve, and Perry counties. The distribution of the lime- 
stones in these counties is shown in detail in the geologic map of 
northeastern Missouri (PI. IX). 
The limestones appear continuously in the river bluffs or in stream 
cuts along the west bank of the Mississippi, from the Iowa State line 
to a point about 10 miles south of Hannibal. Here the Mississippian 
limestones leave the river for some distance, Silurian rocks appearing 
in the bluffs from below Saverton to Cap au Gris. At Cap au Gris 
the limestones again appear, and form the river bluffs as far south as 
Kimmswick, in Jefferson County. Ordovician rocks then appear on 
the river bank for a space of about 12 miles, but about 5 miles below 
Crystal City the Mississippian limestones reappear in the bluffs and 
show almost continuously to a point less than a mile sout|i of Witten- 
berg, Perry County, where they finally disappear. 
COMPOSITION. 
The Mississippian rocks of Missouri include several thick limestone 
formations, with at least one thick series of shales. The limestones, 
as shown in a table of analyses below, are almost invariably good 
Portland-cement materials. 
