THE PRECAMBRIAN ROCKS OF THE CANTON QUADRANGLE 25 



the adjacent border of the sigmoid, and that its pitch is also north- 

 west similar to that of the S-fold, it seems likely that the ledges in 

 question are actually parallel to, and form the peripheral part of, 

 the sigmoid at this point. 



Structurally the detached occurrence of garnet gneiss in the south- 

 east acute angle of the road intersection at Little River is more 

 satisfactory, though even here erosion has rendered difficult the task 

 of deciphering the contortions to which the strata have been sub- 

 jected. Presumably on either side of the hill which is occupied by 

 the garnet rock and accompanying rusty gneiss, limestone is pres- 

 ent, and these masses have acted as nonresistant cushions between 

 which the garnet gneiss has been free to assume a number of com- 

 plex sinuous flexures (see figure 2). 



30 ft, 



Fig. 2 Contorted strata of garnet gneiss in limestone; the outcrop is 

 considerably interrupted, but the fold appears to be a pitching sigmoidal 

 isocline, with axis directed northwest. At this locality the gneiss is inclosed 

 by limestone above (west of dotted Hne), and rusty gneiss or other siliceous 

 gneisses below (east of dotted line), in which case the heavy lines indicate 

 structure only. Length of area sketched, about 100 yards. 



Five-tenths of a mile south-southwest of Little River crossroads. 



The ledge shown in plate 4, upper figure, in which the observer 

 looks toward the northwest, typifies the relations at this locality : 

 large recumbent isoclinal folds with smaller parallel crenulations 

 riding upon their limbs, the whole complex pitching at a moderate 

 angle (20 degrees) toward the northwest. The darker lines or 

 shadows in the illustration mark the position of weathered calcar- 

 eous laminae which serve to accentuate the structure. 



