S2 



GEOLOGY OF THE THIRD DISTRICT. 



at the lead mines, one is N.W., and the other varies from E. ^ E.N.E. to E. i E.S.E. ; at 

 Copenhagen, one is N.E., and the other N.W. Two of the joints are nearly at right angles 

 to each oUier, a third is oblique to the two, and one of the three is often absent. 



The Trenton limestone is an important rock to show the ancient level of all the points 

 where its surface now appears, extending without interruption from East Canada creek to the 

 St. Lawrence river. Its calcareous composition shows that it was a precipitate ; the shale 

 witli which its layers so often alternate, prove that it was deposited in tranquil waters, and 

 •its flat layers confirm the original horizontal positipp of its surface. 



View of the FulU below the Foot-bridge, from a Drawing of R. C. Taylor. 



The cliaracter of the Trenton limestone as a rock, showing its horizontal layers as tliey 

 appear transverse to the stream, and its well-characterized vertical joints, is well exiiibitcd 

 in the wood-cut No. 5, taken at one jof the falls of Trenton, on West Canada creek. The 

 most interesting locality of the Trenton limestone is on this creek. For about two miles, 

 the creek has cut a passage through the limestone ; the sides of the excavation rising verti- 

 cally, with an average height of over one hundred feet. In this passage are the falls or cas- 

 cades which have given so much celebrity to the place, justly meriting by their number, 

 beauty and position, the admiration whicli tliey have received. Including the one at Prospect 

 village, there arc six, falls, five of whicii are placed at intervals somewhat regular, and occupy 

 the middle part of this time-\vrought excavation. The layers generally thougljout this dis- 

 tance, with the exception of the grey variety which forms the upper part of the mass, rarely 



