1887.] ' «^ [Stevenson. 



synclinal between it and the similar ridge of Buckhorn mountain. The 

 valley between these ridges is reported to show only shale. 



The Clinch FaxdU. 

 The Clinch River system of faults continue from Tazewell county into 

 Mercer county of West Virginia, which lies beyond tlie area examined for 

 this memoir. The New Garden fault passes at a little way north from 

 East River mountain and continues eastwardly beyond the eastern 

 limit of Mercer county, as appears from the Rogers' section ; but it is 

 greatly diminished in eastern Mercer, for there it is in Devonian rocks, 

 whereas in Tazewell it brings Quinnimont into contact with Knox lime- 

 stone. The Stony Ridge and Abb's Valley faults certainly disappear before 

 the eastern line of Mercer county is reached, unless their course has been 

 greatly changed, for the writer found no trace of them in Summers 

 county, of West Virginia, where they should be found. 



The extreme vertical extent of the several faults is approximately as 

 follows : 



Draper mountain 12,500 feet. 



Max Meadows' 9,800 " 



Pulaski 9,600 " 



Price mountain 10, 000 ' ' 



Walker mountain 10,000 " 



Saltville 10,000 " 



Wolf creek 2,000 " 



II. THE GROUPS, WITH COMPARATIVE NOTES. 



The section is a long one, reaching from the Umbral of the Lower Car- 

 boniferous to the lower beds of the Potsdam. No detailed measurements 

 were attempted and in most cases no effort was made to estimate thick- 

 nesses. Only the more general features are summarized here, as most of 

 the details given in previous memoirs are equally applicable to this area. 



The, Carloniferoiis. 



The Coal Measures are not reached but the Lower Carboniferous is repre- 

 sented by the Umbral and the Vespertine. These groups are shown in 

 Bland county along the southerly slope of Brushy mountain ; in Wythe, 

 Pulaski and Montgomery counties, they form the foothill of Little Walker 

 mountain ; they are present in Wythe and Pulaski counties in the area 

 between the Max Meadows and Pulaski faults ; and in Montgomery, on 

 Price mountain. 



The Umbral. — Prof. Fontaine makes the thickness of the upper portion, 

 the Umbral red shales and shaly sandstones, to be 1090 feet in Brush and 

 Price mountains of Montgomery county, and the writer finds 996 feet in 

 the New River gap through Brush or Little Walker mountain. In the 

 Memoir on Lee county, &c., the writer regarded these Montgomery 

 county shales as Vespertine, but he now feels that that identification is 



