Maryland Geological Survey 361 



numerous specimens of Spvrifer with a very higli hinge area probably 

 Spirifer marciji var. supcrstes Clarke associated with Spirifer disjunctus 

 Sowerby, and numerous specimens of Ambocoelia umhonata (Conrad). 

 Some of this sandstone is almost pinkish in color and all of it is much 

 stained and blotched with red patches. The sandstone is fairly hard but 

 the shales in this zone are mostly olive and fissile. 



No. 8. Some distance above the stratum containing the numerous 

 specimens of Spirifers are brownish argillaceous shales and thin arena- 

 ceous layers. The succeeding rocks are mostly olive to buff shales and 

 thin sandstone with an occasional layer of brown shale or sandstone. 



No. 9. Almost at the top of Green Ridge is a ledge of brownish-red 

 sandstone and just above are arenaceous shales to mealy sandstone in 

 which fossils occur; as Spirifers, Lyriopecien iricostatus (Vanuxem), 

 Sphenotus contractus Hall and other pelecypods. In one block con- 

 taining a specimen of Spirifer is a white quartz pebble, while on the 

 surface are quite large blocks of conglomerate which apparently formerly 

 capped the hill. It will be seen in the description of the sections on 

 Polish Mountain that blocks of a similar conglomerate occur near its 

 summit. The summits of these mountains were undoubtedly originally 

 covered by this Chemung conglomerate which has been nearly removed 

 by erosion. At first it was supposed to foiin the top of the Jennings 

 formation but in the section west of Cumberland in Jennings Run it is 

 shown that succeeding a similar conglomerate are several hundred feet 

 of rock which still carry Chemung fossils. In the upper part of that zone 

 there are bands of red shales and sandstone of considerable thickness 

 but in the olive shales alternating with the reds axe fossils. The higher 

 rocks, either clear red shales and sandstone or somewhat greenish in color 

 and without fossils, are in the Catskill formation. Evidently Dr. O'Harra 

 considered tlie conglomerate blocks found on Green Ridge as identical 

 with the one in Jennings Run for he wrote that " It [Jennings Run 

 conglomerate] is not well shown on Green Ridge, although there is 

 abundant evidence of its presence, but along the eastern flank of Town 

 Hill [a parallel ridge a short distance east of Green Ridge] it appeal's to 

 be of considerable thickness." * 



' Allegany Co., p. 107. 



