1054 NEW YORK STATE MUSEUM 



eastward rocks are exposed within a few feet of the contact, so 

 that the latter can be readily traced, with some interruptions, to 

 a few hundred feet beyond the central mountain (Newman) road, 

 after which no exposures of the Manlius have been observed for 

 over half a mile northeastward. Hence the actual contact of 

 the Manlius and Coeymans can not be determined, but it can be 

 readily inferred from the positions of the contacts of the higher 

 formations. Beyond this the contact can be easily ascertained, 

 being for the most part actually exposed in the face of the cliff, 

 or at least indicated by rock exposures within a few feet on each 

 side of the actual contact. 



The Stromatopora bed has not been observed along the eastern 

 face of the mountain, but is found in the outcrops along the 

 southern portion. 



For the most part the outcrops of the Manlius appear as a 

 narrow strip on the map. This is due to the fact that this forma- 

 tion, when but slightly inclined, generally makes a cliff, owing 

 to the uniformly compact character and perfect jointing of the 

 rock. When vertical or steeply inclined, a cliff may or may not 

 be formed; in any case the exposure does not much exceed in 

 width the thickness of the Manlius as found at Becraft. Only 

 along the northern end a broad belt of this rock is exposed, for 

 here the inclination is very gentle (10° to 20°), while the slope is 

 likewise a gentle one and for the most part drift-covered. The 

 absence of the usual cliff here may be accounted for by glacial 

 erosion, this being the side most exposed to the force of the ice. 



4 THE COEYMANS LIMESTONE 



This is a compact, finely crystalline, generally dark colored 

 limestone. Fossils are abundant only in the upper layers, the 

 most characteristic species being Atrypa reticularis, 

 Gypidula galeata and crinoid stems. Layers of chert 

 are not infrequent, and in some outcrops form a constant and 

 characteristic feature. There is sufficient argillaceous matter 

 in this rock to give it the characteristic odor when breathed on. 

 The organic fragments are large enough to be recognizable, 

 though there is also a considerable admixture of flourlike 



