73 The Middle Devonian DErosixs of Makyland 



Exposure at Gilpin. — This section is in the northern part of the county 

 (in the National Road and Flintstone Creek to the southeast of Flint- 

 stone. At the eastern end of tlie gap cut by Flintstone Creek through 

 the northern end of Warrior Mountain is the top of the Oriskany sand- 

 stone. The dip of the Upper Oriskany is 31" E. at this locality. The 

 shales at the contact of the Oriskany and Eomney are not showii ; but in 

 the field on the northern side of the road is an outcrop of quite black, thin, 

 argillaceous shale with thin bedded sandstones some distance east of the 

 Oriskany sandstone. 



There are occasional outcrops along the National Road to the east of 

 the Oriskany sandstone and in the eastern part of Gilpin are outcrops of 

 bluish-green shales which in layers are very fossiliferous. A fairly massive 

 sandstone was also noted in this part of the section. 



On the bank of Flintstone Creek just south of and opposite Gilpin 

 is a good exposure of the Hamilton shales in the upper part of the 

 Romney formation. They are bluish and arenaceous with an occasional 

 layer of thin sandstone. The dip is 30° E. Thin lavers of these shales 

 contain abundant fossils as Spirifer mucronatus (Conrad), TropidoUptus 

 ((irinatus (Conrad), Choneies, and a few other species among which 

 may be mentioned Fterinea flahelhim (Conrad). A 3-inch fossil band 

 composed largely of Spirifer mucronaius (Conrad) occurs at the lower end 

 of the outcrop. The shales crumble into rather irregular, angular, small 

 blocks in a manner very similar to that of many of the thin bedded, 

 arenaceous Hamilton shales in New York. The fauna of this locality is as 

 follows: Slroplieodonta (Leptostrophia) perplana (Conrad), Chonetes 

 mucronatus Hall, Chonetes coronaius (Conrad), Clionetes scitulus Hall, 

 Chonetes setiger (Hall), Chonetes lepidus Hall, Chonetes viciiius (Castel- 

 nau) (?), Camarotoechia congregata (Conrad) (?), TropidoJeptus cari- 

 natus (Conrad), A inj pa reticularis (Linne), Spirifer mucronatus (Con- 

 rad), Spirifer granulosus (Conrad), Spirifer tiilliiis Hall, Amhocoelin 

 nmhonata (Conrad), Nucula hellistriata (Conrad), Nuculites ohlongaius 

 Conrad, Nuculites triqueter Conrad, Parallelodon hamiltoniae (Hall), 

 Pterinea flabellum (Conrad) , Mytilarca (Pleihomytilus) oviformis (Con- 

 rad), (?) Modiomorplia STp., ModioniorpJia concenirica (Conrad), Cypri- 



