MIDDLE AND UPPER DEVONIAN OF ROMNEY REGION 23 



tains, to the north of the Potomac River, in Allegany County, 

 Maryland. 



The railroad station and post-ofhce now known as Patterson 

 or Patterson Depot is the locality formerly known as Patterson 

 Creek. There are no exposures in the immediate vicinity of the 

 station, and the Baltimore and Ohio railroad track, along which 

 are several cuts, was followed to the eastward. The first one east 

 of the station shows massive Oriskany sandstone, the greater part 

 of which is hard, light gray, and quartzitic, certain layers contain- 

 ing a considerable number of fossils, particularly specimens of 

 Spirifer arenosus (Conrad), some of which are very perfect. At 

 the eastern end of the cut the rocks dip sharply to the east, while 

 farther to the west they are some distance above the track and 

 nearly horizontal. In the second railroad cut east of the station 

 is another outcrop of the Oriskany sandstone, which is also dipping 

 to the eastward. In some of the partly decomposed layers of 

 brown sandstone there are good specimens of Spirifer murchisoni 

 Castelnau, associated with other Oriskany fossils. From near the 

 center of the cut to the western end there is some of the very hard, 

 quartzitic sandstone. The dip is about 23° S., 70° E. 



At the first hill east of the cut described above are thin, bluish, 

 arenaceous shales which form a low ridge. These shales are rather 

 firm, and when crumbled the pieces are larger than those on the 

 Williams Road to the north in Maryland. No fossils were found. 

 These shales are apparently in the lower, fairly barren portion of 

 the Hamilton member of the Romney formation. It is to be re- 

 membered in this connection that the lower part of the Hamilton 

 formation consists of rather arenaceous shales, in which fossils are 

 of infrequent occurrence. This area is the southwestern con- 

 tinuation of the belt of the Romney formation to the east of ColKer 

 Mountain in Allegany County, Maryland. 



Along the hill by the highway about one mile south of Patterson 

 Depot are outcrops of thin, bluish-black shales which are fairly 

 argillaceous and split into thin pieces weathering to a brownish 

 color. In certain layers fossils are rather thick, especially Ambo- 

 coelia umhonata (Conrad) and Liorhynchus limitare (Vanuxem). 

 Specimens of Coleolus and small-winged Lamellibranchs were also 



