1877.] 55 ( [Ashburner. 



Beside seams Nos. 12 and 14 of the section there are two otlier small beds 

 below the ore sandstone. The first, from 4 to G inches thick, occurs directly 

 under the sandstone and about 50 feet below the upper beds (C. Constable). 

 The second is 10 inches thick and about 4 feet below the first. These two 

 beds have never been worked. The beds above the sandstone are worked 

 on the south side of Rockhill Gap by two drifts 100 feet vertically apart 

 and having an average course of S. 21° W. The same beds are worked 

 also on the north side of the Gap by two drifts which are about 60 feet 

 vertically apart, the strike being about the same as on the south side. The 

 course of the south drifis when continued across the Gap to the north side 

 strikes about 100 feet to the west of the north openings, the ore range being 

 thrown to the east on the north side by a fault which runs through the 

 Gap at right angles to the strike. In gangway No. 1 on the south side the 

 yield of a specimen was as follows : 



No. 14. No. 12. 



Iron 50.800 per cent. 50.700 



Sulphur trace. trace. 



Phosphorus 113 .133 



The ore sandstone has a thickness of 43 feet at Saltillo and of 50 feet at 

 Orbisonia. 



The sandstone varies very much in character in the different localities, 

 as to the amount of calcareous matter which it contains ; at Rockhill Gap 

 it is very silicious, while at Saltillo it is quite calcareous. In the latter 

 locality the ore beds seem to be represented by a calcareous sandstone con- 

 taining a large percentage of iron, but not a true iron ore. 



The sandstone generally forms a terrace along the flank of the mountain 

 of No. IV. 



4. Lower olive shale (Nos. 9 and 10). — Thickness : 660 feet. — For descrip- 

 tion see section 



The following fossils were found in the Clinton Epoch, more particularly 

 in the upper olive shale : Atrypa reticularis, Beyrichia lata, BtUhotrepMs 

 gracilis, Dalmania Umulurus, Homalori.otits delphinocephalus, OrtMs 

 elegantula, Platyostoma niagarensis, Pterinea emacerata, Rhynchonella 

 neglecta and Strophomena rhomboidalis. 



No. IV. Medina (Levant) Sandstone, 



White sandstone, No. 8 Thickness 400 feet, f ^ nnr^, 



Red sandstone and shale, No. 7 " 930 " | 



The white sandstone contains in New York several characteristic fossils, 

 some of which the marine plants, and more particularly the Arthrophycug 

 harlani, are found throughout its whole range from Pennsylvania to the 

 south border of Tennessee. 



The red sandstone and shale member is in Pennsylvania entirely destitute 

 of fossils, and is a coarser and more sandy rock, than in New York, where 

 it is composed principally of a finely-comminuted red marl or a calcareous 

 red clay, containing a few organic remains. 



PKOC. AMER. PHILOS. SOC. XVI. 99. 3r 



