788 



FREDERIC H. LAHEE 



sandstones and coarse and fine mudstones. These variations in 

 texture are frequent, thus giving rise to a very uniform, closely 

 spaced bedding lamination or banding (see Fig. i). The strata 

 have a pretty regular southeastward dip of 2o°-2 5°. Minor undula- 

 tions are seen here and there, but these are easily recognized as of 

 orogenic origin and were no doubt formed at the same time with the 

 larger deformation of which the inclination of the beds is evidence. 



Fig. 2. — Hand specimen of the truncated folds seen at Squantum. Here the folds 

 are not very strongly overturned. The length of the specimen illustrated in the 

 figure, is about eight inches. 



At several stratigraphic levels in the series, at intervals of a 

 few feet, are belts or zones in which the primary banding has been 

 compressed into small folds (Fig. i) . Downward in the strata these 

 folds diminish in size until they disappear, i.e., they grade into 

 unfolded beds (Fig. 2). Above, they are sharply truncated by 

 beds of similar nature, which have not been distorted. The little 

 folds are all overturned in the same direction. Sometimes the 

 overturning is shght, as in the figure. At other times the overturn- 

 ing may actually pass into overthrust faults having a displacement 



