Studies in the Geeiogy of Montreal and Vicinity. G9 



the dyke runs across the surface, and its relative age as 

 compared with the dykes whicli it cuts, which age may be 

 ascertained by examining the intersection of the two 

 dykes and noticing which is broken across and cut through 

 by the other. Collections from a series of dykes of differ- 

 ent ages which cut one another, if accompanied by a note 

 as to which each cuts and is cut by will always be of great 

 value. 



Mount Eoyal itself offers a most excellent opportunity 

 for the detailed study of one of the great problems of 

 modern geology — that of the mutual relation of igneous 

 magmas in volcanic centres, and the collecting of material 

 for study as above outlined would be a real contribution 

 toward the solution of the problem. 



Again, for those members of the Society whose interest 

 lies more particularly in the domain of mineralogy, there 

 is a field of especial interest in the Corporation quarry, 

 above mentioned, at Outreraont. Here in the cracks and 

 crevasses of the nepheline syenite and the limestone near 

 its contact with the igneous rock, a number of very rare 

 and strange minerals have been found, and a careful 

 search would probably be well repaid by the discovery of 

 additional specimens, and possibly of entirely new species. 



Another series of very interesting geological problems 

 and studies are presented by the " Drift " which mantles 

 the surface of the Island and constitutes its soil. This is 

 the most recent of our geological deposits, and is well 

 exposed in almost every excavation made in and about the 

 city. It has been well described by Sir William Dawson 

 in his book entitled " The Canadian Ice Age," but fresh 

 information is continually to be obtained from new open- 

 ings. Such new openings should in every case be studied, 

 the order of succession of the various strata noted, and 

 their respective thickness recorded. In this way informa- 

 tion may often be obtained which later on it would be 

 impossible to procure. 



