10 Geological History of the Ozark Uplift — Broadhead. 
while south of Sandy creek the Burlington limestone is elevated 
at an angle of 80°, and not far down the bluffs the St. Louis 
limestone is seen reposing horizontally. 
The Cap-au-gr^s axis crosses the Illinois river six miles above 
its mouth. In Missouri it passes north-west and is recognized 
along its line by a series of sink holes, and is soon lost beneath 
more recent rocks. 
Another axis seems to branch off from this, coming to view 
near Auburn, in Lincoln county, thence near Prairieville, Pike 
county, and Frankfort and Jones siding, showing the Lower 
Trenton near Freeman's and Trabue's lick on Salt river, Ralls 
county, and is last seen in a slight rising of the Chouteau beds 
near Newark, Knox county. 
The Lower Carboniferous (Keokuk group) appears on the 
east fork of Charitoii in Randolph county, indicating a slight 
uplift, for the adjacent and neighboring rocks are all of the age 
of the Lower Coal Measures. 
A few miles north of Cameron, in DeKalb county, there is a 
slight disturbance of the Upper Coal Measures cracking and 
tilting the strata, and subsequent filling of the cracks with 
calcareous vein matter. 
The Mississippi channel is apparently along or near the axis 
of a monoclinal fold; the Missouri river evidently so, from St. 
Charles county to Cooper, its channel being directly on the 
strike of the monoclinal and thus limiting the northern exten- 
sion of the Ozark plateau. On the Missouri bluffs from 
Augusta to within a few miles of St. Charles there is a down- 
throw of 1,000 to 1,200 feet, leaving the St. Louis limestone 
nearly horizontal at St. Charles; but as we pass westwardly the 
Keokuk group ascends in the bluffs, then the Burlington, then 
the Chouteau, then the Trenton, Black River and Birdseye 
groups, until finally the Magnesian limestone series with 133 
feet of Saccharoidal sandstone; and as we approach Augusta the 
Second Magnesian limestone is apparently nearly horizontal. 
Along the Missouri, from St. Charles to Boone, the strata 
are nearly horizontal, the Second Magnesian limestone capped 
with First sandstone forming the escarpments along the river. 
At Hermann the Second sandstone appears at the base of the 
bluff, and while the First sandstone is generally the cap rock 
on the south side of the river, we find the Trenton group occu- 
