524 Canadian Record of Science. 



small part of the mountain, and is altogether covered by 

 the altered limestone, with the exception of some heavy 

 bands of Theralite and smaller ones of Syenite, indicated 

 by the crosses on Eig. 4, which appear to have broken 

 through it, and to extend in a northerly direction towards 

 the main body of trap in Cote des iSTeiges Cemetery. 



There is, however, at various points on the Little 

 Mountain evidence of intense volcanic activity. On the 

 eastern side, in a large C[uarry, the limestone has been 

 changed by the action of heat so that it resembles a fine 

 marble, and in some cases has been reduced to what 

 appears to be a quicklime, which readily slacks on expo- 

 sure to the atmosphere or moisture. 



Another side of the quarry is cut by narrow dykes 

 in different directions, while a large part of it is occupied 

 by a breccia, cut by a heavy dyke of Theralite. Speci- 

 mens of these are also shown. 



On Summit Avenue, at a point about 100 feet below 

 the top of the mountain, there is a large dyke of gray 

 Syenite, about 8 feet in thickness. About twenty-five 

 feet, in a north-easterly direction, there is another dyke 

 of dark, close-grained trap 12 inches in thickness, and 

 between them a horizontal outcrop of Theralite. 



Besides this, there are on this side of the mountain 

 a large number of dykes, from 1 inch' up to 2|- feet in 

 thickness, for the most part a hard, dark colored trap, but 

 showing Theralite at different points, and in some in- 

 stances much decomposed. 



At the northern end of the mountain, near the reser- 

 voir, there is another large quarry, showing an outbreak 

 of massive, dark, fine-grained trap, fianked by a heavy 

 deposit of breccia, while the limestone is greatly altered 

 by the action of heat, which does not appear, however, to 

 have produced the same effects on the lime as in the 

 quarry on the eastern side, l)ut left it with a dark bluish 

 purple tint instead of white. 



