237 Devonian of Southern Indiana 109 



( Chester group. 



-r r^ u •£ St. Louis group. 



Lower Larbonirerous. < ^^ . . ^ ^ 



Keokuk group. 



[ Knobstoue group. 



■p. . f Black slate, or "Genesee .shale." 



Devonian. ■{ ^ ■. 



( Lortiuerous. 



Maurice Thompson in his first report gives the same classifica- 

 tion of the Devonian as Collett and states that "the Corniferous 

 rocks and the Genesee shale are the two numbers of the Devonian 

 found in Indiana."* 



In 1897 Prof. H. S. Williams published a paper "On the 

 Southern Devonian Formations."! No dire(5l reference is made 

 to the region under consideration in this paper, but the idea is 

 presented that the upper and lower limits of the "Black shale" 

 formation may vary with reference to the time scale in different 

 regions, and that the formation contains locally, at least, Eocar- 

 boniferous faunas. 



The Report of the Indiana State Geologist for 1897 contains a 

 paper on the "Geological Scale of Indiana" by Blatchley and 

 Ashley. The authors recognize three divisions of the Devonian 

 in Indiana — the New Albany or Genesee shale, the Hamilton, 

 and the Corniferous. The Hamilton is recognized in the north- 

 ern part of the state on the authority of Dr. Phinney, but the <iu- 

 thors state that "the formation has not been recognized in south- 

 ern Indiana.";}; No evidence is offered in connecftion with ihis 

 statement to show that Hall'sH determination of the Hamilton in 

 southern Indiana is incorre(5t. 



Correlation of Faunas. 



It has been shown in another part of this paper that the New 

 Albany shale and the beds below it ' are unconformable south of 

 Louisville. As a result of this unconformity the Devonian lime- 



*i5th Rept. Ind. Dept. Geol. and Nat. Hist., 1886, p. n. 

 tAm. Jr. Sci., vol. 3, 1897, pp. 393-403. 

 t22d Ann. Rept. Ind. Dept. Geol. and Nat. Res. 

 ||Pal. N. Y., vol. 5, pt. 2, pp. 139-154. 



