POSTGLACIAL FAULTING ABOUT MOUNT TOBY 



77 



according to Fairchild,' some 300 feet — less to the south and more to the north. 

 Such an uplift would be expected to cause some fracturing of the unequally 

 affected land-mass. This fault is described in detail because it can be posi- 

 tively dated — that is, between the time of Lake Hadley and the present. 



WHITMORK ■ 

 FERRY 



FiGUKE 1. — Map of Mount Toby, Massachusetts 



Oj Long Meadow delta ; i, Dug Brook delta ; c, north end of down faulted area ; x-y. 

 fault shown in figaire 2 ; y-!s_, fault shown in figure 3. 



On Mount Toby there are dozens of fault escarpments breaking the glacier- 

 smoothed rock surface, which about here is so little weathered. The Sunder- 

 land Cave is such a case. Here three parallel joints have formed, outlining 



■'II. L. Fairchild : Postglacial uplift of southern New England. Bull. Geol. Soc. Am., 

 vol. 30, p. 597. 



