NO. 1851. WAVERLYAN PERIOD OF TENNESSEE—BASSLER. 221 



from Whites Creek toward Ridgetop, the same thing happens. At 

 Union Hill, 4 miles east of the Whites Creek section, the New- 

 Providence division and the Fort Payne chert are both splendidly 

 exposed, but the former is here much reduced in thickness. A few 

 miles farther east the Xew Providence disappears entirely, as shown 

 in the Ridgetop section. The Whites Creek area, therefore, seems 

 to have been the site of an embayment of the Nashville Island in 

 New Providence times. Considering the location of the area and 

 the lithologic and faunal similarity of these deposits to those of the 

 same age in the vicinity of Louisville, Kentucky, it seems probable 

 that the latter were laid down in the northern part and those at 

 Wliites Creek near the southern end of a trough paralleUng the 

 Cincinnati axis. So far as known, the New Providence did not 

 extend to the east of this axis. Similar embayments of Richmond 

 and Niagaran times have been described by Hayes and Ulrich.^ One 

 of their embayments terminates in the northeastern corner of the 

 Columbia sheet, and it is possible that detailed mapping will show 

 the New Providence formation of the Whites Creek area, which is 

 less than 25 miles to the north, to have been deposited in a continua- 

 tion of the same trough. If true, we have a good example of the 

 permanence of these embayments. The extent of the submergence 

 o*f this trough varied at least in Richmond and Niagaran times, for 

 the older deposits stretched some miles farther south than did the 

 Niagaran invasion. From evidence here presented and elsewhere 

 in hand it appears that deposition was still more restricted in Waver- 

 lyan transgressions. Thus, with each transgression the extent of 

 each subsequent invasion was progressively less, until, in New 

 Providence time, the submerged area extended only a few miles 

 south of Wliites Creek Springs. As brought out by Hayes and 

 Ulrich, even the Chattanooga shows evidence of earlier deposition 

 confined to these embayments, with the later Chattanooga spreading 

 far and wide over their borders. Following this New Providence 

 time of greatest restriction, at least of these embayments, the long 

 and general submergence of the Fort Payne sets in, doubtless covering 

 the whole dome. 



The development of these shales and limestones in the Whites 

 Creek area has a noticeable effect upon the present topography. In 

 areas where the siliceous Fort Payne rests upon the soft Ridgetop 

 shale or upon the Chattanooga shale, the descent from the Highland 

 rim to the Central Basin is usually very steep. The intercalation of 

 a loosely cemented fragmental, fossiliferous Hmestone in the W^hites 

 Creek area causes a bench to be developed in this otherwise steep 

 descent, so that from a study of the topography one is almost able 

 to determine the outline of the area containing the New Providence. 



I Columbia Folio, U. S. Geol. Surv., Folio No. 95, 1903. 



