120 W. M. Fontaine— Vespertine Strata of Virginia. 



limestone by faults in its most easterly known exposures, renders 

 it difficult to draw any conclusions from a change of thickness. 



Brush Mountain lies to the north of Price's Mountain, and is 

 separated from it by a belt of Lower Silurian limestone about 

 1£ miles wide. Its structure is very simple. The northern 

 foot is composed mainly of Chemung strata, while the central 

 mass is formed of the lower member of the Vespertine, which 

 extends some distance down the southern slope. A portion of 

 the southern face and foot of the mountain is composed of the 

 middle or coal-bearing member, while a band of red rocks 

 belonging to the upper member forms the foot-hills next to the 

 limestone belt. By the great fault, mentioned before as run- 

 ning on the western side of the valley of Virginia, this mass of 

 strata has been brought down so as to abut against the Lower 

 Silurian limestone. Though there has been no overturn of the 

 strata, yet some slight - da has been produced, 



causing a considerable amount of rubbing and crushing. This 

 has made itself felt, especially in the coal, which in consequence 

 is much more fractured and rubbed than that of Price's Moun- 

 tain, yet by no means so much so as that of Augusta and 

 lam counties. Poverty Creek, after flowing for some 

 distance along the north side, cuts directly through this moun- 

 tain, and gives a good section of all the strata of the Vespertine. 

 The dip is 30° S.S.E. toward the fault. My section was taken 

 - creek, commencing on the north side in the Chemung 

 beds, and proceeding south to the upper member of the Ves- 

 pertine. 



The Chemung beds show the same character here as at Lewis 

 Tunnel. The same alternations of flaggy sandstone and shales, 

 with thin layers containing numerous impressions of shells, are 

 found. These beds are to be seen within a space of 400 feet, 

 under the lowest of the Vespertine strata. This interval was 

 too much concealed to enable me to determine whether it is 

 occupied by Chemung beds, or strata which may be the equiva- 

 lents of the Catskill. If the latter are present here, they must 

 be less than 400 feet thick. 1 am inclined to think that they 

 e entirely absent, having been replaced by the greatly thick- 



Xiower member of the Vespertine. 



1. Massive white conglomerate and sandstone, 80 fee 



2. Massive white sandstone, with layers of conglomei 



3. Thin-bedded white siliceous sandstones, 100 feet. 



4. White and yellowish flags, marked with red spots 



300 feet. 



5. Siliceous gray sandstones and flags, 300 feet. 



Total for the lower member, 930 feet. 



