DESCRIPTION OF THE ECONOMIC AMD GEOLOGIC MAP 869 



in one belt. The boundary between the Hamilton and Portage 

 ^roup accords very nearly with the views of Prof. C. S. Prosser. 



In addition to the text of the reports, the following published 

 maps have been consulted : 



Geologic maps of Jefferson and Clinton counties, by E. Em- 

 mons, Natural History of New York, Report on the Geology of 

 the Third District, 1842 ; a geologic map of Ontario county, by 

 J. M. Clarke, Report of the State Geologist for 18S5 ; a geologic- 

 map of Yates county, by B. H. Wright, Thirty-fifth Annual 

 Report of the New York State Museum, 1881 ; a geologic map 

 of Onondaga county, by Geo. Geddes, Report of the New York 

 State Agricultural Society, 1859 ; a sketch map of the Mohawk 

 Yalley, by James Hall, Report of the State Geologist for 1885 ; 

 a geologic map of Washington, Rensselaer and Columbia coun- 

 ties, by C. D. Walcott, American Journal of Science, vol. 35, p. 

 399; geological maps of parts of Dutchess and Columbia coun- 

 ties, by J. D. Dana and W. B. Dwight, American Journal of 

 Science, a geologic map of parts of Orange and Ulster 

 counties, by John C. Smock, part of geologic map of New 

 Jersey, 1868; a map of Richmond county, by N. L. Britton, 

 Annals of New York Academy of Sciences, vol. 2, revised by 

 C. A. Hollick. The work of T. Nelson Dale, in Rensselaer 

 county, Thirteenth Annual Report Director United States Geo- 

 logical Survey, has also been used. McFarlane's Geological 

 Railway Guide has been freely consulted. To Prof. James Hall, 

 State Geologist, the thanks of the author are due for information 

 concerning the geology of many localities. 



To the second edition of the map Prof. Dwight has contrib- 

 uted an original map of Dutchess county, and Profs. H. L. 

 Fairchild and P. H. Hargitt have respectively contributed to the 

 geology of Rochester and Syracuse. 



Mr. N. H. Darton's work in Ulster county, published in the 

 Report of the State Geologist for 1893 has also been used. 



The localities of iron mines are chiefly taken from the map of 

 Prof. J. C. Smock.* The stone quarries are chiefly from Prof. 

 Smock's map,f with additions by Wm. G. Eberhard, E. M., and 



* Bulletin of the New York State Museum, No. 7. 

 t Bulletin of the New York State Museum, No. 10. 



