STRATIGRAPHIC CLASSIFICATION DIASTROPHIC CRITERIA 42? 



While Kinderhookian deposits are always thin and but locally devel- 

 oped on the west limb of the Cincinnati axis, the equivalent of the Fern 

 Glen — that is, the New Providence shale — is of fair thickness and per- 

 sistently developed in Indiana and west central Kentucky. On the 

 west side of the Nashville dome, however, it is still found only in certain 

 small, synclinal embayments of the old shore which had previously 

 lodged similar narrow arms of Eichmondian and Niagaran seas. The 

 Burlington proper seems entirely unrepresented by deposits in the 

 area between the Mississippi south of St. Louis and the western side 

 of the Appalachian Valley south of Kentucky. In this area the Osagian 

 is represented only by the New Providence shale already mentioned 

 and by the Fort Payne chert which is correlated with the Keokuk only. 

 The Fort Payne facies occurs generally and with very little variation 

 in Alabama, Tennessee, western Kentucky and southern Illinois. It 

 is well developed also in eastern Missouri south of St. Louis, resting 

 here, as a rule, on the Fern Glen. Finally, it is present also rather 

 commonly on the southern side of Ozarkia, being represented in whole 

 or part by the Grand Falls chert member of the Boone in the Joplin 

 district of southwestern Missouri. Apparently, the Keokuk is absent 

 entirely on the northwest and north sides of the uplift. 



Tennessean differential movements. — The Keokuk was succeeded by 

 a long period of emergence. The Warsaw represents the first deposits 

 of the next invasion of the continent in southeastern North America. 

 In the Mississippi Valley proper the Warsaw seems to have had an 

 essentially similar, though more restricted distribution than the preceding 

 Keokuk, failing to extend so far north in Iowa and not so far west on 

 the east flank of Ozarkia. In southeast Missouri the Warsaw was posi- 

 tively recognized only in St. Louis, Jefferson, and Ste. Genevieve coun- 

 ties, where it rests on beds correlated with the Keokuk. On the north 

 and west sides of the Ozark uplift neither of these two formations is 

 present, but near the southwest angle, in an embayment extending north- 

 ward through Washington and Benton counties in Arkansas, beyond 

 Carthage, Missouri, more or less cherty beds, beginning with the Short 

 Creek oolite, are found filled with fossils proving their early Tennessean 

 age. They rest on or form an upper member of the Boone chert, a for- 

 mation usually regarded as comprising deposits representing both the 

 Burlington and the Keokuk. After a close study of the character and 

 distribution of the rocks and faunas of the Osage group, I have been 

 forced to the conviction that the Keokuk is sometimes but poorly or not 

 at all represented by deposits in the Boone. In other words, the Keokuk 



