Maryland Geological Survey 87 



gray laminge which contain few fossils. The lower beds of the Coeymans 

 present a marked contrast, being massive, blue, crystalline and highly 

 fossiliferous. The base of this member often contains limestone pebbles 

 while the line of contact with the Keyser member is usually somewhat 

 sinuous. These features, together with its arenaceous character in some 

 localities, as on Elbow Eidge, suggest the probable existence of an un- 

 conformity at the top of the Keyser. 



The New Scotland Member. 



Character and Thickness. — In N"ew York the upper portion of the 

 Coeymans limestone becomes thin-bedded and this character continues 

 into the next higher zone. These thin-bedded limestones and the inter- 

 bedded shales are abundantly fossiliferous. One of the common forms is 

 Spirifer perlamellosus which in the days of the original New York State 

 Survey was referred to the genus Delthyris; hence the name Delthyris 

 shaly limestone. Until 1899 this was the recognized name, but it was at 

 that time changed to New Scotland to conform to modern usage. The 

 member is named from New Scotland in Albany County, New York. 



The New Scotland of Maryland comprises two divisions. The lower 

 beds consist of courses of limestone, usually 4 to 8 inches thick, containing 

 numerous layers of white chert, which replace the limestone and form in 

 many cases the larger part of the whole. The chert weathers out into 

 large, very irregular, ragged pieces, which cover the surface of the soil. 

 Owing to their resistance to solution the New Scotland and Oriskany 

 cherts unite to fonn high ridges upon the summit of which they outcrop. 

 These ridges are conspicuous features in the topography of Allegany 

 County and adjoining parts of Pennsylvania and West Virginia. 



The upper beds of the New Scotland member consist of soft, drab, 

 fissile shale which contains but little calcareous material. The shale is 

 seldom exposed, but its position is usually indicated by a slight depression 

 visible upon the summit of the ridge between the Oriskany and New Scot- 

 land cherts. This shale is absent in the Hancock area. 



Such lithologic characters are quite different from those in New York 

 where the lower limestones are thin-bedded, with intercalated shales and 



