136 KOYAL SOCIETY OF CANADA 



At a number of points around the borders of the great central coal 

 basin, and most conspicuously along the valley of Shin Creek, a branch 

 of the South Oromocto river, are large masses, sometimes forming con- 

 spicuous hills, of quartz-porphyries, trachytes, etc., indicating extensive 

 igneous outflows, but of which the exact age is uncertain. Their rela- 

 tions to the great bands of argillites which inclose the Carboniferous 

 basin would indicate that they are newer than the latter, but the 

 further fact that they have largely contributed to the formation of the 

 Lower Carboniferous conglomerates shows that their production ante- 

 dated the latter. They may be either Silurian or Devonian. 



So in northern New Brunswick, along the valleys of the Becca- 

 guimic, T|0.bique and Serpentine, large ta-act.s of felsitic racks occur, 

 as to the age of which little is definitely known. In the case of the 

 Toibique, where they form, the bulk of the so-called Blue Mts., a 

 conspicuous feature in the scenery of that stream, they have been 

 assigned partly to a Pre-Cambrian and partly to a lower Carboniferous 

 hori?on, but from such observations as the writer has been able to make 

 are quite as likely, with the very similar beds of the upper ISTepisiguit, 

 already discussed., to be Silurian. Tihose found on the Beccaguimic 

 and the Serpentine are, in his opinion, only peripheral form of granitic 

 extrusion. Much more work, both in the field and with the microscope, 

 must yet be made, before either the true age or character of these wide- 

 spread eruptions will be accurately known. 



Triassic. 



The last geological formation in New Brunswick which is notice- 

 able as giving evidence of volcanic activity is the Trias or Trias-Jura. 

 On the mainland it is but slightly represented by a few small and 

 isolated areas upon the southern coast, ,but, taken in connection with 

 the similar rocks so strikingly exhibited upon the opposite shore of the 

 Bay of Fundy, and again at the mouth of the latter, in the island of 

 Grand Manan, they point to a period and phase of vulcanism, wliich 

 is of the highest interest. 



In Grand Manan, a portion of the territory of New Brunswick, 

 the volcanic rocks constitute fully two-thirds of the whole island, 

 extending its whole length, with a breadth varying from two to five 

 miles. At the northern end of the island is revealed an admirable 

 natural section, the successive accumulations of volcanic material 

 being superimposed upon each other in such a way as to form a series 

 of conspicuous sheets, locally known as thé " six days of creation.," A 

 closer examination shows these to be in part composed of a distinctly 



