644 



Report of the State Geologist. 



C n . From the brow of the cliff to the top of the hill. Partly 

 covered but showing ledges of Calciferous sandrock to the top of the hill. 



The Calciferous sandrock forms the top of this hill and n<> indication of 

 the Trenton was found. The Fonda sheet of the United States topographic 

 map shows that the difference in altitude between the New York Central 

 railroad and the top of this hill is between 560 and 580 feet. This section 

 shows at least 450 feet of Calciferous sandrock to which, probably, the greater 

 part if not all of the covered 112 feet at the base of the section should be 

 added, which would indicate a thickness of more than 500 feet of Calciferous. 



Tribes Hill and Fort Hunter. 



North Side of the Mohawk. 



Tribes Hill is a small village about half way between Fonda and Amster- 

 dam, and opposite the mouth of the Schoharie creek, which enters the 

 Mohawk river from -the south. The Trenton limestone is exposed on both 

 sides of the Mohawk at this locality, the most extensive outcrop being in the 

 quarry below the railroad and the cut above it just west of the Tribes Hill 

 station. The section of this quarry and railroad cut is as follows : 



XLIV A 1 . Compact, dove-colored limestone, with smooth fracture, 

 weathering to an ash-grey color. The basal layer in the eastern part of the 

 quarry ; its contact with the underlying rock not shown. Birdseve limestone. 



A % . One or two layers of very lumpy, fine-grained blackish lime- J=\ 

 stone with small, sparkling crystals of calcite. Very few fossils ; now and 

 then a specimen of Rafintsquina alternata (Con.), H. and C, and Strep- 

 t< lasma, sp. This zone is doubtfully referred to the Black river limestone. 



A z . Massive, dark blue limestone, mostly fine-grained but with if= et 15 

 crystalline layers which usually contain some fossils, St freptelasma being the 

 most abundant. In the eastern end of the quarry the limestone has almost 

 the appearance of a single layer, though it divides along several indistinct 

 bedding planes. Trenton limestone. 



A 4 . Varies from thin, very unevenly bedded greyish, crystalline 

 to dark-colored, highly fossiliferous limestone. Lower part appears as a thick 

 layer when freshly opened. 



A 5 . Thin-bedded, uneven, dark-blue limestone in the railroad cut l 43 

 above the quarry. Trenton. 



The dip varies in different parts of this exposure as, for example, in one 

 part of the quarry it is 5$°, S. 45° W., and in the railroad cut 4°, S. 50° W. 



