THE 



JOURNAL OF GEOLOGY 



MAY-JUNE, 1904 



A SERIES OF GENTLE FOLDS ON THE BORDER OF 

 THE APPALACHIAN SYSTEM.^ 



The conclusions of this paper have been reached in the study of 

 the Watkins Glen quadrangle, New York. This quadrangle com- 

 prises the four fifteen-minute quadrangles known as the Watkins, 

 Ithaca, Elmira, and Waverly quadrangles. Extending from the 

 Pennsylvania state line to the Seneca and Cayuga Lake valleys, it 

 includes the southern portion of each. This area lies immediately 

 north of the region of the Appalachian folds. The surface rocks of 

 the quadrangle are the shales and sandstones of the Chemung, 

 Portage, and Genesee formations. The rock strata over much of 

 the area vary so little from the horizontal position that the dip can 

 usually be recognized only by the very careful use of the clinometer 

 or the level. Dips high enough to be conspicuous, and ranging from 

 8 to 55°, have been noted occasionally in various parts of the quad- 

 rangle, but these higli dips have in nearly all cases been found to be 

 associated with small lo'^al anticlines or faults, extending frequently 

 only a few rods and possessing only local interest. With these higher 

 dips the present paper is not concerned; but the interpretation of the 

 more obscure dips ranging usually from i to 3 or 4° will be attempted. 



A careful study of the low dips characterizing the rocks over the 

 major part of the quadrangle has shown them to have an important 

 structural significance. They have been found to represent a series 

 of low, approximately parallel, anticlinal folds, ha^"ing the same 

 general direction as the great mountain folds immediately south of 

 them in Bradford county, Pennsylvania. 



I Published by permission of the director of the U. S. Geological Survey. 

 Vol. XII, No. 4. 281 



