APPLICATION OF PRINCIPLE OF TRANSGRESSIVE OVERLAP 577 



In the region about Knoxville, Tennessee, the Shenandoah becomes 

 known as the Knox dolomite and has a thickness of 3,500 feet. Beneath 

 it, southeast from Bays mountain, is from 8,000 to 9,000 feet of shales 

 and limestones, with occasional sandstone members, which are especially 

 prominent toward the base, where extensive conglomerates occur.* 



The series comprises : 



Maximum 



thickness 



Feet 



Knox dolomite 3,500 



Nolichucky shale 550 



Marysville limestone 550 



Rogersville shale 220 



Rutledge limestone 450 



Rome formation (shales) 250 



Rome sandstones 700 



Beaver limestones 300 



Apison shale 1,100 



Hesse sandstone 500 



Murray shale 300 



Nebo sandstone 500 



Nichols shale 800 



Cochran conglomerate 1,600 



Sandrock shale (with Starrs conglomerate lentils farther southwest) . . 1,000 



Total Chilhowee 8,820 



Farther to the northwest f all the formations between the Eome and 

 the Knox dolomite are represented by the Conasauga shale series, with a 

 thickness of from 600 to 800 feet. This may be a nearer-shore forma- 

 tion, and the diminished thickness from 1,280 (minimum) or 2,770 

 (maximum) to 600 or 800 feet may be due to a rise of the top of 

 the sandstone member underlying, which, from lithic similarity, is here 

 also called Borne. Owing to the non-exposure of the base, the exact 

 relation of these beds to the underlying pre-Cambric land surface can not 

 be determined. In western Virginia J all the members above the Borne 

 formation are shown with slightly increased thickness. The lowest 

 formation is the Bussell sandstone, 1,400 feet thick, but without ex- 

 posure of the base ; so we do not know whether the Bussell is a basal bed 

 or whether the lower beds are concealed. Since these beds are along the 

 strike of the strata, as shown in the Knoxville folio, it seems probable 

 that they are of the same age, and that hence the equivalent lower beds 

 occur in the embed of this region. 



* Keith : Knoxville folio. 



t Briceville folio. 



J Rome, Tazewell, Bristol, Estillville, Morristown, and Briceville folios. 



