l82 NEW YORK STATE MUSEUM 



of the characteristic and abundant New Scotland fossil, S p i r i f e r 

 m a c r o p 1 e u r a , was found in these chert-bearing beds and that 

 Gypidula galeata continues very abundant, it was thought 

 better to place this in the Coeymans than in the New Scotland 

 division. 



For detailed discussion of this horizon, see sections C, D and F. 



i 



New Scotland beds ■ 



The New Scotland beds represent an alternation of dense, dark 

 blue, compact limestone with dark gray shales and thin-bedded sand- 

 stones. The limestone is at times very full of chert bands which in 

 places make up almost half of the rock mass. These chert bands, 

 like many of those in the upper Coeymans are, when weathered, one 

 mass of fossils. This is a specially good place for the collection of 

 the more delicate organisms. The arenaceous limestone beds at 

 times exhibit a succession of light and dark laminae of paperlike 

 thickness, as at K 15, L 2, and L 3. These thin beds contain either 

 very few or no fossils except in the very lowest band. An exceed- 

 ingly rapid change from a comparatively clear to a very black muddy 

 water condition appears to have made it impossible for life to exist. 

 Changes of current are also indicated by the appearance of pockets 

 of coarsely grained limestone in the finely grained at L 3. 



This formation is divided into an upper and a lower horizon. 

 The division is based primiarily on the great abundance of S p i r i - 

 fer cyclopterus in the upper 125 feet; this is exceedingly 

 rare in the lower 45 feet. Spirifer macropleura is the 

 diagnostic fossil of the New Scotland and is abundant throughout 

 its whole extent. To the lower New Scotland are apparently con- 

 fined such forms as Favosites sphaericus and many 

 bryozoa, e.g. Orthopora rhombifera, O. regularis 

 and Monotrypella? abrupta. Fragments of Lingula 

 and Orbiculoidea occur frequently in calcareous, phosphatic, clay 

 nodules ; no manganese could be detected in these nodules.^ 



^In the upper New Scotland of western Maryland, Schuchert notes the 

 occurrence of manganese-phosphatic nodules similar to those dredged from 

 the present deep seas, but he does not think these indicate a deep water 

 condition here, for the " stratigraphic evidence denotes a shallow sea before 

 and after New Scotland times." U. S. Nat. Mus. Proc. 26:420. 



