CARBONIFEROUS FORMATIONS OF THE OZARK UPLIFT 337 

 THE DEPOSITION OF THE CARBONIFEROUS FORMATIONS. 



The Chouteau and Burlington. — The Chouteau and the Burling- 

 ton Hmestones he unconformably upon the Cambro-Silurian dolo- 

 mites, the Burlington apparently overlapping the Chouteau. The 

 pre-Burlington land surface was of the same order of ruggedness as 

 the present, and the sea advanced over the land too rapidly to cut it 

 into a submarine plain. North of the Osage River BurHngton out- 

 liers occur both on the hilltops and in the valley below. South of 

 the Osage the present land surface is lower than the Burlington sea 

 bottom, and only residual Burlington bowlders are now found there. 

 Since this old topography was not base-leveled, several uplifts may 

 have occurred between the Trenton and Burhngton. 



Residual Burlington chert indicates that the early Carboniferous 

 sea covered all Missouri but the country surrounding the St. Francois 

 Mountains. If land existed around them, it must have been inca- 

 pable of furnishing large amounts of clastic material to the sea. Fos- 

 sils show that the sea was teeming with animals too fragile to resist 

 heavy waves, but requiring gentle currents to furnish food material. 



The interval between the Burlington and Coal-Measure deposi- 

 tion. — Elevation, with contemporaneous erosion, produced, by the 

 time of deposition of the Coal-Measure rocks, a topography similar 

 in ruggedness to the present topography. The thickness of the 

 Burhngton limestone appears to have varied from 40 to 180 feet. 



At the beginning of the elevation the rivers had renewed strength, 

 but until the Burlington limestone, which is lacking in clastic grains, 

 was cut through, erosive tools were- doubtless lacking. Still solution 

 occurred on a large scale, as shown by the deposition of the Saline 

 Creek cave-conglomerate and the Coal-Measure shale in joints, 

 enlarged by solution, in sinks and in caves. The inter-Carbonifer- 

 ous conditions were doubtless somewhat akin to those now existing 

 in limestone regions in the tropics, in which we know caves and sinks 

 to be very abundant. The extent to which observation shows solu- 

 tion occurred warrants a somewhat full discussion of the principles 

 of solution. 



The conditions favoring solution^ are : 



I The rest of this section is the appUcation to a particular area of principles set 

 forth in Van Hise's forthcoming treatise on Metamorphism. 



