SOO IfEW YOEK STATE MUSEUM 



New York county "^ 



Tliere is an extensive exposure of white crystalline limestone 

 of Cambro-Silnrian age on the west side of the Harlem river, at 

 and south of Kingsbridge; several exposures also occur in Morri- 

 sania, and at other points in the county. 



The two following analyses of the white limestone from Kings- 

 bridge were kindly furnished by Mr G. A. Stone : 



Silica 7.15 10.2 



Ferric oxid and alumina 1.06 3.33 



Lime 39 . 57 27 . 32 



Magnesia 10.02 17.99 



Niagara county^ 



Limestone passes through the towns of Royalton, Lock- 

 port, Cambria and Lewiston. In this county the Guelph, or 

 magnesian member, is missing, but the lower member is of in- 

 creased thickness. The lower beds overlying the shale are apt 

 to be somewhat silicious, but the upper ones are a crinoidal 

 limestone of greater purity. 



The following section of beds composing the l^iagara limestone 

 at Lockport is given by Prof. Hall.^ 



5 Thinly laminated, blackish gray limestone mth thin laminae 

 of bituminous shaly matter, the whole exhibiting a tendency to 

 a concretionary or contorted structure and the surface of the 

 layers marked by small knobs. 



4 Grayish brown bituminous limestone, the lower part with 

 irregular cavities containing spar. 



3 A dark colored limestone with cavities and veins of spar 

 often concretionary. 



2 Irregularly thick bedded limestone of a light gray color, also 

 containing cavities lined with spar. 



1 Kemp, J. F. Geology of Manhattan island, {see Trans. N. Y. acad. sd. 

 1888. 7: 49-64) 



• Merrill, F. J. H. Crystalline rocks of southeastern New York, {see 



50th an. rep't N. Y. state nrns. 1898. 1: 2-31) 

 Mather, W. W. Geol. 1st dist. N. Y. 1843. 



2 Hall, James, {see Geol. 4th dist. N. Y. p. 440) 



Grabau, A. W. Guide to the geology and paleontology of Niagara 



Falls and vicinity, (see Bui. 45. N. Y. state mus. 1901) 



3 Gool. 4th dist. N. Y. p. 89. 



