54 GEOLOGY OF THE THIRD DISTRICT. 



On the opposite side of the creek, there is a disturbance equally as limited as the preceding. 

 It is at some height above the water. The layers appear to have been bent downwards, and 

 pushed outwards, or toward the stream ; of which the wood-cut will give an idea. 



These instances of disturbance in rocks arc cited, because they are wholly local, and show 

 that some parts may be greatly disturbed, whilst contiguous ones remain totally unaffected. 

 The former instance is of importance, because it throws light upon myriads of similar ap- 

 pearances in the primary class of rocks, and in gneiss and mica slate particularly. Where 

 such minerals as quartz and feldspar, with but little mica, or any other mineral in like amount, 

 form rocks, they ^how but little tendency, as a general rule, to form layers or other like divi- 

 sions, and hence such rocks are termed unstratified ; but where mica or talc forms an impor- 

 tant part of the mass, the disposition in layers occurs. These are straight or waved, curved 

 or contorted, and the latter often to so great a degree as to exemplify an angular movement. 

 It would appear, that where desiccation and crystallization had been simultaneous, the result 

 would be a plane surface, the acting forces being supposed equal ; but that wliere the con- 

 torted and angular appearances occur, the nucleus being usually quartz and feldspar, these 

 have been the active powers, commencing first to crystallize, and the mica or other lamellar 

 mineral the passive one, as exemplified by the two substances which form the contorted mass 

 at the Great falls. 



The village of Prospect is on the alluvion resting upon the Trenton limestone, which there 

 forms the surface rock ; being at the head of the falls, and but a short distance to the west of 

 the excavation. The present direction or channel of West Canada creek is but one of many 

 which it has had, the last of which was through the site of the village, passing south, and 

 parallel to the present one. 



At Prospect bridge there are some local disturbances in the rock, which may have facili- 

 tated the first movements of the water in making its present deep channel. In examining 

 the layers of which the sides of the excavation are formed, we perceive that the lower the 

 layer near the bottom of the channel or passage, the greater is its inclination, dipping down 

 the stream ; and the higher the layer, the less the inclination. Just below the bridge, the 

 layers rise again by a low but graceful undulation, and then resume the usual inclination 

 which they show throughout the excavation. Should the lower inclined layers have extended 

 to the surface north of the bridge, and with the same or a lesser angle, which is likely to have 

 been the case, then their position tvould have greatly aided the destructive forces ; and when 

 once the course of tlie water was fixed, its movement, from the dip of the rock, would be 

 greatly increased. 



