370 NEW YORK STATE MUSEUM 



Wm. C. Clarke, E. M. The clay localities were mapped by M 

 Heinrich Ries,* the oil pools by Messrs. C. A. Ashburner and I 

 Van Ingen, the salt wells by R. D. "White, Jr., C. E., and tb 

 gypsum quarries by Wm. C. Clarke, E. M. The other minen 

 localities were mapped by the author. 



In preparing the base, various practical difficulties had to b 

 met. Among these were the lack of accurate information coi 

 cerning the boundaries of the Chemung and Catskill formatioi 

 in New York, the impossibility of undertaking any new fiel 

 work, and the lack of sufficient funds to permit of more than fi 

 teen printings in the press work of the map. It has, therefor 

 been necessary to emphasize the economic character of the ma 

 rather than the geologic character, to associate in color, rocks c 

 similar economic or lithologic features, and for lack of inform; 

 tion and funds for printing, to indicate without differentiate 

 the great mass of sandstones, shales and conglomerates include 

 between the base of the Portage and the top of the Catskill. 



When the large geologic map of New York, now in preparj 

 tion by the State Geologist, is published and distributed, ther 

 will be a definite expression of opinion on the boundaries ej 

 these formations, but at present there is no official presentatio 

 of the subject. 



The map will be found in the pocket of the cover of the bull< 

 tin and the legend will explain the various tints and symbols usee 



Geologic Map of Westchester and New York Counties. 



Since the scale of the State economic map is not sufficient! 

 large to give in detail the areas of building stone, in New Yor 

 and Westchester counties, a map of that region is publishe 

 on a scale of four miles to one inch. This map is based on th 

 studies of the author and shows the present state of geologi 

 knowledge in that region. 



Economic Minerals of New York. 



Under this head are described the minerals of New Yor 

 which are commercially important. So far as possible a director 

 of the producers has been prepared for each mineral product 



* Bulletin of the New York State Museum, No. 12. 



