Stevenson.] °^ [March 18, 



or the same as No. 2, of Mr. McCreath's analyses of Tom's Creek coals. 

 These analyses show that the proportion of the volatile combustible mat- 

 ter decreases north-eastward, so that one is prepared to find not a semi- 

 bituminous coal such as these, but a true anthracite in Narrowback moun- 

 tain at the Dora mines further north-north-east, near Harrisonburg. 



The material for comparison of the areas lying further south-east, in 

 the Valley, does not exist. No analyses of coals in the area between Max 

 Meadows and Pulaski have been made, so far as the writer knows ; only 

 one analysis of the Price Mountain coals by McCreath, and one of the 

 Catawba coal in Botetourt county by Rogers, have fallen under the 

 writer's notice ; these show : 



Price mountain 13 87 



Catawba 21 79 



a very notable difference. "Whether or not the specimens were taken from 

 different parts of the same bed or from different beds cannot be ascertained. 

 The Vespertine coal beds attain their chief importance within the coun- 

 ties of Wythe, Pulaski, Montgomery, Roanoke and Botetourt, a distance 

 along Little Walker mountain of barely 105 miles. But isolated patches 

 of slight extent preserved in synclinals within Augusta and Rockingham 

 counties, show that the field with beds of workable thickness extended to 

 certainly 100 miles further north-north-east, thus giving a length directly 

 measured of nearly 200 miles. Exposures in Wythe, Pulaski and Roanoke 

 show that the Vespertine beds reached far into the area now known as the 

 "Great Valley," fragmentary patches still remaining at a distance of 

 barely twelve miles from the Archtean, while exposures in Bland and Rock- 

 ingham show that the productive coal area in Virginia extended to some 

 distance beyond the line of the Saltville f;iult. Certainly it was 200 miles long 

 by fifteen miles in Virginia ; and the width may have been twelve miles 

 greater toward the south-east, reaching to the Archi^an. The whole area 

 may be estimated at beyond 5000 square miles, of which only insignificant 

 strips and patches have escaped erosion, amounting in all to not more than 

 130 square miles. How much further north-eastward this area extended 

 cannot be determined, for in Pennsylvania and Maryland the numerous 

 folds with the disappearance of the faults have thrown the most easterly 

 outcrop of Vespertine, to a distance from the Archaean greater than that 

 of the Abb's Valley fault from the Archnean in Virginia. No workable 

 coal beds occur in Pennsylvania and Maryland within the Vesper- 

 tine, but what existed in that portion of the Vespertine which has been 

 removed by erosion, we may conjecture from the conditions occurring in 

 Virginia within the same space. 



Within Virginia the coal beds diminish quickly in importance in all direc- 

 tions from the area already defined. South-westward, the coal-bearing 

 division of the Vespertine diminishes and the last trace of it occurs on 

 the North fork of Holston, near Mendota. in Washington county, where 

 coal is said to be found'in the river-bottom at low water. North-westward 



