34 ROYAL SOCIETY OF CANADA 



SO far as these Tobique rocks have been examined, they closely resemble 

 in character the volcanics of western Charlotte county (felsite and 

 diabase), which have already been described as probably late Silurian 

 or Devonian in point of time. This group of volcanics may therefore 

 be correlated with the Charlotte county eruptives. 



At Nictor lake, volcanic rocks have a large development, rising 

 almost from the water's edge to elevations of 1,500 to 2,600 feet above 

 sea level. The largest of them, known as Sagamook or Bald mountain, 

 is flanked on the north or lake side by Silurian slates containing scat- 

 tered pebbles of felsite in the lowest portion. They have a schistose 

 structure in places, and resemble very closely in this respect certain 

 parts of the Silurian of Charlotte county. The alteration does not 

 resemble that resulting from the action of igneous rocks which have in- 

 truded through the slates, since there are no crystals of slaurolite or 

 allied minerals, such as are found elsewhere in connection with the 

 granite masses. It appears rather to be caused by regional movements 

 subsequent to the deposition of the Silurian sediments. 



This range of volcanic hills has not been examined in detail to the 

 westward, owing to the great difficulty found in traversing this district. 

 To the east, however, they have been traced for some miles, and they 

 occur on both sides of the ISTipisiguit. They extend eastward to within 

 about five miles of the Portage brook, which is a small tributary of the 

 Nipisiguit from the north, along which a portage route extends across 

 to the head waters of the Upsalquitch and thence to the Eestigouche. 

 Throughout this chain of volcanic hills the rocks are largely felsitic in 

 character, but occasionally they pass into granites. The felsites are 

 sometimes hard and porphyritic, and occasionally show a well-denned 

 flow structure, which on first sight presents the aspect of true bedding. 



East of this chain of hills, the rocks, as seen in the ridges on either 

 side of Portage brook, are for the most part crystalline schists, in places 

 gneissic, resembling the pre-Cambrian schists of southern New Bruns- 

 wick. They are as a series, quite distinct both from the altered Upper 

 Silurian and from the volcanics. They extend north from the 

 Nipisiguit along Portage brook and the upper part of the Upsalquitch 

 for some ten miles, where they are overlaid by conglomerates with 

 pebbles of the underlying rocks, felsites and hard slates, the series con- 

 taining Upper Silurian fossils, and passing up into the characteristic 

 Silurian slates and limestone of the Upsalquitch-Eestigouche basin. The 

 southern limit of the Silurian rocks is therefore definitely fixed in this 

 direction. 



A prominent hill, which is known locally as the Peak of Teneriffe, 

 rises to the south of the lower of the three lakes which form the head 



