284 



NEW YORK STATE MUSEUM 



Ladder road and the only one climbing these precipitous cliffs 

 between New Salem and Altamont. The Tentaculite [Manlius] 

 and Pentamerus [Coeymans] limestones form the prominent 

 cliff which extends from New Salem around the northern end 

 of the mountains to Altamont; but on the higher terraces and 

 hills to the south the later formations are found, and their 

 distribution is shown on the " Preliminary Geologic map of 

 Albany County, N. Y.", by N. H. Darton. 1 Along the Indian 

 Ladder road are exposures of the upper part of the Lorraine beds, 

 with magnificent cliffs of Tentaculite [Manlius] and Pentamerus 

 [Coeymans] limestones ; while to the east and south the succeed- 

 ing hills show the later formations up to the lower part of the 

 Hamilton, which forms the upper part of Signal station hill. 2 

 The section from Meadowdale to the top of Signal station hill is 

 as follows [in descending order] : 



Feet Total 



Hamilton; arenaceous shales to thin sandstones at 

 the base; but mainly shales to the top of Signal 

 Station hill. Some specimens of the small Ham- 

 ilton lamellibranchs, as Palaeoneilo con- 

 st r i c t a (Con.) Hall ; N u c u 1 a b e 1 1 i s - 

 t r i a t a (Con. ) Hall ; Nuculites triqueter 

 Con. ; N . oblongatus Con. and others, are 

 found in the shales in the upper part of this hill. 



Exposed 130-1495 



Covered 20-1365 



Marcellus shale; black argillaceous shales exposed 

 along the road up the hill to the south of the New 

 Salem road and in the gullies on the northwestern 



side of the hill 170-1345 



Onondaga limestone; well shown in the upper part of 

 the terrace to the north of the New Salem road. 

 The upper part of the formation forms the floor 

 of this road for nearly two miles on the plateau. . 98-1175 

 Schoharie grit; shown on a south road at the base 



of the light gray Onondaga limestone 3J-1077 



Esopus shale; finely exposed along the road to the 

 cast of the brook and house. Another excellent 

 exposure occurs in the glen to the east of tlie 

 eastern north and south road which on the 

 plateau connects the Indian Ladder and New 

 Salem roads 100-1 073J 



X N. Y. State Gool. 15tb An. Rep't 1895; 



2 Tlie station was called Helderberg and is 1823 feet A. T. (Final results 

 of the Trian-nhition of the X. Y. State Survey. 1887. p.iii). 



