University of the State of New York 



New York State Museum 



Bulletin 77 

 GEOLOGY 6 



GEOLOGY OF THE VICINITY OF LITTLE FALLS, 

 HERKIMER COUNTY 



AREA COMPRISED IN THE LITTLE FALLS QUADRANGLE 

 PREFACE 



The study of the crystalline rocks of the Adirondack area by 

 modern petrographic methods was begun in 1892 by Prof. J. F. 

 Kemp under the direction of the writer in connection with the 

 iron ore deposits in the vicinity of Port Henry and some results 

 were published in Museum bulletin 14, Geology of Moriah and 

 Westport Toimiships, Essex County, N. Y., tvitli notes on the iron 

 mmes. Subsequently this work w^as continued and extended 

 under the direction of Prof. James Hall, and Professors C. H. 

 Smyth jr and H. P. Gushing were invited to participate in the 

 study of this great crystalline area. The work of the three investi- 

 gators in their separate fields has been published in the reports 

 of the state geologist for 1893 and subsequent years, and has 

 resulted in a wholly new light being thrown on the structure 

 and geologic history of the district. Professor Cushing's special 

 field has been the Northeastern Adirondacks and having suc- 

 cessfully covered the part alloted to him so far as the existing 

 maps of that region would permit, it seemed that it would 

 be of much interest to make a detailed comparison of the northern 

 pre-Cambrian geology with that of an area bordering on the 

 Mohawk valley. The Little Falls quadrangle having been com- 

 pleted, this suggested itself as a convenient and interesting field 

 for work. Professor Gushing accordingly, as a result of a careful 

 study of this area, communicates the following report. 



Frederick J. H. Merrill 



State Geologist 



