42 



the Pre-Cambrian rocks indicates a movement parallel 

 to the general fault but the horizontal limestone above 

 crosses this fault plane without interruption, thus showing 

 that it is of pre-Trenton age. 



Contact of Trenton and Pre-Cambrian, top of Montmorency Falls. 



Across the stream a small gully heading to the east has 

 the gneiss for its northern wall, and at the bottom are a 

 few layers of Upper Trenton limestone, followed by more 

 limestone with Triarthrus becki and graptolites. The 

 greater part of the southern wall of the gully however, is 

 shale, and the contact of the Utica and the Lorraine may 

 readily be seen, the Utica shale being much the darker of 

 the two. The contact is a very irregular one, but this 

 irregularity probably does not indicate an uncomformity, 

 but rather that the effect of the fault has been to cause 

 the Lorraine to slip somewhat upon the Utica. The point 

 of rock which is so constantly bathed by the spray is Utica 

 shale, and graptolites, chiefly Climacogr aphis bicornis and 

 Climacograptus typicalis are quite plentiful on the side 

 toward the falls. The Lorraine shales are not, in general, 

 very fossiliferous, but certain layers contain a quatity of 

 graptolites and incomplete specimens of Triarthrus becki. 



