46 THE CANADIAN NATURALIST. [Vol. vl. 



presented in accordance with one of these conjectures, the one as 

 of Lower and the other as of Upper Silurian age. 



That the great belt of trappean rocks which form so marked a 

 feature both in the physical structure and in the geology of Grand 

 Manan, is of much more recent date than is supposed in the 

 above observations, will, I think, with a full knowledge of the 

 facts, scarcely admit of doubt. After a careful examination of a 

 considerable part of their area, both as exposed in the shore cliffs 

 and over the interior, I have no hesitation in re-affirming the 

 comparison, long since made by Dr. Gesner, between these rocks 

 and those of the North Mountains of Nova Scotia. So far as I 

 have had an opportunity of examining the latter, their resem- 

 blance to those of Grand Manan is very striking, as well in their 

 composition as in their general aspect, while both are quite unlike 

 anything met with among the older recognized formations of New 

 Brunswick. These traps at Grand Manan, though largely strati- 

 jfied, have evidently come up through the older metamorphic rocks 

 of the island (which are at some points, as at the Swallow Tail 

 Light, intersected by large dykes of exactly similar character), 

 and were probably contemporaneous with the similar outflows at 

 Blomidon and elsewhere, but whether the period of this eruption 

 is to be assigned to the Triassic or to a still more recent epoch, 

 is as yet undetermined. As tending to confirm the view of the 

 Mesozoic age of these rocks, I was fortunate in being able to 

 examine in situ the sandstones referred to, but not seen by Prof. 

 Verrill, as sometimes occurring with them. These are rarely met 

 with, (at least in that part of the island visited by me) being ex- 

 ceedingly soft and easily worn away except where protected by 

 overlying masses of harder trap. They may, however, be seen 

 near the entrance of Dark Harbor, the principal and almost the 

 only break in the continuity of the western shore, and are said to 

 be exposed at other points as well. In their features of softness 

 and incoherence, as well as in their peculiar light red colour, these 

 sandstones resemble very closely those of the Annapolis and Corn- 

 wallis valleys in Nova Scotia, or those which, at Quaco and else- 

 where on the southern coast of New Brunswick, have been refer- 

 red to the New Bed Sandstone Era.^ 



* G. F. Matthew — Observations on the Geology of St. John County, 

 N.B. Also, Bailey and Matthew— Observations on the Geology of 

 Southern New Brunswick. 



