372 The Upper Devonian Deposits of Makyi.and 



Total 

 Thick- thick- 

 ness, ness. 



No. 1. At the eastern end of the road cut are shales and sand- 

 stones of the upper part of the Romney formation, 147 feet shown. 



No. 2. Covered portion 30 30 



No. 3. Thin black argillaceous shales splitting into very thin 

 pieces which are even and smooth, and weathering to a slightly 

 brownish tint are excellently shown in this cut, which in many 

 respects is the best exposure of Genesee shale known in Maryland. 

 The shales are quite fossiliferous as for example, Styliolina fls- 

 surella (Hall) is abundant in certain layers while Buchiola retro- 

 striata v. Buch and Pterochaenia fragilis (Hall) are not un- 

 common. This exposure of shale is quite similar to many in the 

 typical outcrops of the Genesee shale in central New York with 

 which it is correlated. The contact between the Genesee and Wood- 

 mont is clearly shown and at the top of the black Genesee shales the 

 rocks become coarser in texture and thin sandstones occur alter- 

 nating with shales. The line of division is drawn where the thin 

 sandstones appear, a little to the east of the sycamore tree near the 

 middle of the upper part of the cut. Within 5 feet there are bands 

 of sandstone 2 to 3 inches in thickness alternating with the shales, 

 and the lithological appearance of the rock is unmistakably that of 

 the Woodmont stage. This is the best exposure of the contact of the 

 Genesee shale and Woodmont shale known in Maryland. From 

 these black shales Dr. J. M. Clarke has identified the following spe- 

 cies: Buchiola retrostriata v. Buch, LunuUcardium cymbula Clarke, 

 Paracardium doris Hall, Pterochaenia fragilis (Hall), Styliolina 

 fissurella (Hall), Bactrites aciculus (Hall), Proheloceras lutheri 

 Clarke ( ?), Tornoceras uniangulare (Conrad) 73 103 



To the northeast of this exposure Professor Stevenson reported 

 two outcrops of the Genesee shale in Napier Township in the west- 

 ern part of Bedford County, Pennsylvania.^ 



No. 4. On a fresh fracture the thin shales have a rather bluish 

 color and alternate with thin sandstones of similar color, both of 

 which weather to a greenish tint and here and there are iron- 

 stained. In the upper part of this zone the sandstones are thicker 

 than in the lower portion; one being 9 inches and several others 

 nearly as thick 38 141 



No. 5. Prominent massive bluish-gray sandstone, which weath- 

 ers to a greenish tint, 2 feet, 9 inches in thickness. This is the 

 most prominent stratum in the upper part of the cut and may be 

 readily located 2+ 143+ 



No. 6. The shales above are bluish argillaceous and arenaceous, 

 and a little higher mainly greenish shales occur alternating with 

 thin sandstones. The greater part of this upper portion is in the 

 field at a short distance from the road. These rocks are all in the 



' T=, p. 82. 



