DEFORMATION OF ROCKS 341 
It has been pointed out (p. 331) that in ordinary folds the 
movement is relatively up for a higher stratum as compared with 
the one next below it. In the case of over- 
turned monoclinal folds (Figs. 3 and 4) the 
later differential movements of the strata on the 
longer limbs of the folds may continue quite to 
EVERETT SCHIST 
—_——— 
and past the crests of the anticline, so that the 
differential movement on the shorter limbs of the 
folds is relatively down for the superior stratum 
geologically as compared with the inferior. How- 
ever, in this case, when the folds are overturned, 
with reference to the horizon on the inverted 
limb, the movement of the higher stratum would 
still be upward, as compared with the one below 
it. This may be called reverse differential move- 
ment, and it may continue so as to more than 
compensate for the normal differential move- 
ment, but the resultant differential movement 
2 would be less on the steeply inclined or over- 
i turned limbs of the folds than on the longer, 
flatter limbs, since on the latter the motion is 
continuously in the same direction. 
CANAAN LIMESTONE 
In the case of monoclinal folds it will be 
shown in my paper in the following number of 
this JouRNAL that the shearing is greater on the 
longer, more gently inclined limbs than on the 
shorter, more steeply inclined limbs. As a result 
MT ALANDAR 
of this the former are not so thick as the latter 
and are usually more metamorphosed. 
Examples of composite folds—In the United 
States, Mount Greylock, the Taconic range, and 
the valley between constitute a great normal 
{j > 
SSIS 
— 
— 
————S 
anticlinorium. The same is true of Mount Wash- 
— = 
ington, in Massachusetts (Fig. 19). A cross- 
= 
—— 
——— 
—_J 
NIESS 
RIGA SCHIST 
section of the central part of the Marquette 
district furnishes an example of a great abnormal 
