W. M. Fontaine— Vespertine Strata of Virginia. 119 



south side, being in the former case 30° N.N. VV., and in the 

 latter, 26° S.S B. The coal of the upper bed on the north side 

 is somewhat thicker than that on the south side. The lower 

 bed is essentially the same on both sides. The lower bed 

 everywhere averages about two feet. 

 flags, and separated from the upper b 

 same kind of rock. 



An average section for the upper bed on both sides, is as fol- 

 lows, commencing at the top: 



1. Black slate, (roof). 5. Slate, 7 inches. 



2. Coal, 12 inches. 6. Coal, 10 inches. 



3. Slate, 12 inches. 1. Slate, (floor). 



4. Coal, 2| feet. 



No. 4 sometimes runs up to three feet, and the other layers of 

 coal show occasionally an increase of several inches in thickness. 

 The following section, omitting details, will give the char- 

 acter of the red upper member, commencing below: 



1. Interstratifieation of brown sandstone, and red shale, 50 feet. 



2. Red and mottled marlites, with some brown sandstone, 440 ft. 



3. Thinly fissile, red shales, " " " " 600 feet. 

 A regular change mav be traced in the character of these 



sediments. No. 1 and No. 2, in the lower portion, have a larger 

 proportion of sandstone. But in the greater portion of No. 2, 

 especially the middle and upper parts, and in all of No. 3, the 

 sandstone appears onlv in occasional beds. The lower portion 

 of No. 2 is often mottled with spots and streaks of gray and- 

 green. The indications are that the strata were deposited dur- 

 ing a steadily progressing subsidence. , 



This thickness of 1090 feet of ;te3 »s sud- 



denly cut off on the northern side, by the Lower Sihn 

 stone, which throughout this region has a southeast dip, and 

 shows a considerable amount of alteration. No remnant of the 

 Lower Carboniferous, or Lewisburg limestone, is seen here, and 

 if it were ever present, it has been removed by erosion, it is 

 clear that this mass of red strata was deposited prior to this 

 limestone, if it were ever formed here. In any case we would 

 have a great development of the upper member, as compared 

 with the same near Lewis Tunnel, and this agrees well with the 

 development of the two underlying members in this region. 



1 am inclined, however, to think that all of these beds were 

 not deposited before the limestone. The increasing fineness ot 

 the upper portion No. 3, and other indications that this part was 

 formed in comparatively deep and qniet waters, make it quite 

 probable that No. 3 is the representative here of the limestone. 

 So far as I know the limestone has been seen by no one so far 

 to the east. The sudden cutting off of the Lower Carboniferous 



