124 ROYAL SOCIETY OF CANADA 



masses at once attracts attention. "Where the lime-rock, through the 

 presence of disseminated graphite, is itself dark coloured, the course of 

 the dyke is still made evident, as is also the metamorphic action of the 

 escaping fluid, by the fact that for an inch or so on either side of the 

 latter the rock is pure white, the graphite having been apparently com- 

 pletely burned away. Still another effect, well seen in some of the 

 excavations on the hill sides overlying the village of Kandolph, is the 

 occurrence, near to and in parallel planes with the limestone, of con- 

 spicuous bands of coarse garnets and other minerals. 



The dykes vary greatly in width as they do in frequency of associa- 

 tion, as regards the former feature being sometimes only an inch or two 

 wide and in other cases eight or ten feet, while as regards the latter they 

 are sometimes few or isolated and at other times thickly clustered. 

 Bifurcations of the dykes, End interruptions due to the previous jointing 

 and dislocations of the beds are not uncommon. The usual attitude 

 is one of steep inclination like that of the beds with which they are 

 associated. These latter are most commonly limestones rather than 

 slates or quartzites. Some of these features are well shown in the 

 accompanying plate. 



There can be but little doubt that the dykes referred to are of Post- 

 Laurentian origin, and are or once were connected with the great sur- 

 face flows which distinguish the next succeeding system. They may 

 in general be described as diabases, though often much altered and 

 usually finer grained and less distinctly crystalline than the rocks of this 

 nature to be presently noticed in connection with later formations. 



Huronian. 



This system is above all others the volcanic system of New Bruns- 

 wick, resembling in this respect the same system as found elsewhere. 

 Indeed it contains little that is not more or less nearly the result of 

 volcanic activities, and it was for this reason, together with its position 

 between the supposed Laurentian rocks already referred to and the 

 fossiliferous Cambrian strata, about St. John, that as early as 1864 the 

 claim was made by the writer and his colleague, Dr. Gr. F. Matthew, that 

 the rocks in question were the representatives of the Huronian system 

 £s found on the shores of Lake Huron. 



The areas covered by these volcanic products axe large, including 

 considerable tracts in St. John, Kings and Queens counties, where, 

 owing to their power of resistance, the rocks usually form somewhat 

 conspicuous hills. The latter also show considerable variety of composi- 

 tion and texture, including felsites of various colours and degrees of 

 fineness, diorites both coarse and fine, ash rocks, amygdaloids, trachytes 



