22 Tuscaloosa Formation [220 



the Tennessee River across Walden Ridge, I cannot help 

 believing that the Cretaceous ancestor of this stream at the 

 beginning of Tuscaloosa time, instead of making the sharp 

 turn to the northwest at Guntersville, Alabama, which it does 

 at present, continued southwestward down either Brown or 

 Big Spring valleys and reached the sea through either the 

 Mulberry or Locust fork of the Warrior River. This, how- 

 ever, is not an essential part of my argument for the delta 

 character of the Tuscaloosa formation, since there was obvi- 

 ously at that time a stream or a series of streams draining to 

 the southwest and engaged in removing the debris of the long 

 weathered land mass. 



SW NE 



POTTSVILLE 



FIG. 2. 



Section showing relation of the Tuscaloosa deposits to those of 

 the Eutaw and Selma formations. 



I do not wish to be understood as ignoring the fact that 

 some of the Tuscaloosa deposits are sub-aerial and that ori- 

 ginally the delta deposits probably continued inland up the 

 valley or valleys for considerable distances as continental de- 

 posits of channels, flood plains and lakes. The antecedent 

 meanders of the present streams give clear evidence of con- 

 ditions that prevailed on the Cumberland peneplain that were 

 suitable for the formation of ox-bow lakes. There must have 

 been quiet waters in the delta itself in certain bayous or 

 possibly lakes like lakes Salvador, Ponchartrain and Borgne 

 of the present Mississippi delta region. Certainly the leaf- 

 bearing clays near Glen Allen and Shirley's Mill in Fayette 

 County, Alabama, were formed in such quiet bodies of water 

 with densely wooded shores. 



The relations of the Tuscaloosa formation emphasizes its 

 delta character as is shown in the accompanying textngure. 



