MISSISSIPPIAN OF PHELPS COUNTY, MISSOURI 575 



but are closely related. This fauna is probably Warsaw, but, in 

 the absence of detailed faunal studies of the Warsaw, a more exact 

 correlation cannot be made. 



Briefly summarized, the results of this study show that the faunas 

 obtained from these residual bowlders are much more diverse than 

 has previously been supposed. They indicate a partial sub- 

 mergence, in early Mississippian time, of a considerable portion of 

 the northern end of the Ozark uplift. From the study of so small 

 an area, not much is to be inferred as to the movements and dis- 

 tribution of the Mississippian seas during the time when the forma- 

 tions represented in these bowlders were deposited. 



Typical Chouteau faunas and pre-Chouteau faunas are con- 

 spicuously absent, though farther north the Chouteau formation 

 is represented by small outliers and scattered patches of bowlders. 

 From this it would seem as if the sea did not cover this part of the 

 uplift during Kinderhook time, but that a gradual submergence 

 during the late Kinderhook allowed the Burlington seas to invade 

 this area. This supposition is further strengthened by the sandy 

 character of many of the bowlders, which suggests that the ancient 

 shore line was not far distant. An alternative view is that the 

 Kinderhook formations, or part of them, were present, and, not 

 being as resistant as the younger formations, have entirely dis- 

 appeared. However, if this is the case, why should the Chouteau 

 formations occur as bowlder deposits in the counties between this 

 area and the Missouri River ? On the whole, the evidence seems 

 to favor the first hypothesis. 



Not much evidence of the Upper Burlington with its typical 

 crinoid fauna has yet been found, but some specimens in the 

 original School of Mines collection suggest that it was represented. 

 In most places where it is exposed at present it contains much less 

 chert than does the Lower Burlington, and this fact may account 

 for its failure to be more commonly preserved. The Keokuk and 

 the Lower Warsaw are probably both represented, but so great is 

 the similarity between their faunas that the few collections which 

 have been obtained do not suffice to make the distinctions clear. 

 Up to the present time, no evidence has been obtained of any 

 faunas younger than the Lower Warsaw. 



