REPORT OF THE STATE PALEONTOLOGIST 1901 657 



southern end of the trough by several small patches, in Polk 

 county, Ga., some 20 miles north of Tallapoosa. These patches 

 evidently are remnants of a tongue of this formation that ex- 

 tended northeastward to this point and occupied a syncline along 

 the eastern side of the Valley trough, this particular syncline 

 being now almost entirely covered by overthrust Ocoee slates 

 and conglomerates. Its connection with the main body of the 

 Fort Payne deposit is at present conjectural. 



The shore line of the main body of the early Mississippian 

 sea followed the western side of the Rome barrier rather closely 

 to probably some point in Virginia, where it broke through the 

 line and sent tongues southward in secondary depressions within 

 the Appalachian valley synclinorium. These secondary depres- 

 sions may in a general way be said to have been occupied at an 

 earlier period by the sea which laid down the Devonic Black 

 shale, and which entered the trough probably through the same 

 opening. Subsidence of the middle third of the Valley trough 

 continued in second half of Mississippian time, resulting in 

 greater expanse in the Appalachian region of Newman limestone 

 and Pennington shale, which, together, represent the St Louis 

 and Chester deposits of the Mississippi valley. These forma- 

 tions, however, do not extend over much of the basinlike area 

 occupied by the early Mississippian- Waverly sea in Ohio, north- 

 oast Kentucky and the adjoining corner of West Virginia, the 

 Waverly basin, lying between the middle Tennessee-Cincinnati 

 line of uplift and the Appalachian-Chilhowee barrier, having 

 been in St Louis and Chester times, much reduced in its northern 

 and northwestern extent. 



The Carbonic strata of Michigan were deposited in a basin 

 formed by the bifurcation of the Cincinnati axis, and probably 

 had only a slender or possibly no direct connection with the 

 Waverly basin to the southeast of it. At any rate, the evidence 

 in hand indicates that, if the connection existed at all, it was 

 severed about the beginning of the St Louis age. 



The coal measures east of the Mississippi river were inaugu- 

 rated by a slight subsidence beginning perhaps with an ice age. 



