[ells] interesting PUOBLEMS in new BRUNSWICK geology 3S 



waters of the Nipisiguit river, its elevation above the lake near the base 

 being about 1,260 feet. On this mountain, at a height of about 400 

 feet there is an exposure of grey sandstone, shale and conglomerate 

 lying nearly flat on the southern face of the mountain. The shale 

 holds plant stems, and the whole closely resembles Devonian rocks seen 

 along the Upsalquitch, and at points along the lower Eestigouche at the 

 head of the Bay des Chaleurs. These sediments are practically un- 

 altered. They have apparently not been subjected either to local meta- 

 morphism by igneous rocks or affected by crustal movements. They 

 have no connection with the rocks of the great Silurian basin to the 

 north and west, but are apparently the remains of a somewhat, at one 

 time, extensive area of Devonian sediments, the greater portion of which 

 has long been removed by denudation. Another small Devonian outlier 

 is found to the westward on the Campbell branch of the Tobique, but 

 the characters of the rock and of the contained fossils is somewhat dif- 

 ferent to those seen in the outlier on Mount Teneriffe. From the ex- 

 amination of the whole range of these felsite and granite liills, it would 

 appear that they owe their present position to intrusion, as is the case 

 with the somewhat similar masses in the southern part of the province, 

 and not to overflows over the great areas of Upper Silurian, which lie 

 to the north. 



Tn regard to the age of these northern felsite hills, it may be said 

 that portions of them resemble very closely the old felsite masses of the 

 pre-Cambrian areas east of St. John, but in the absence of typical Cam- 

 brian sediments in this district, their pre-Cambrian age cannot be de- 

 finitely asserted, though on their first examination they were so re- 

 garded. In so far as the more recent examinations have been made 

 no definite evidence has been obtained to warrant, at present, any great 

 change of opinion on this point. Certain portions of these hills are un- 

 doubtedly older than Silurian, while the post-Silurian age of the diabase 

 and felsite rocks along the lower Tobique, and at a number of points 

 between this area and the Bay des Chaleurs, has long been known, and 

 has been pointed out in earlier reports. It is therefore very probable 

 that in this volcanic area igneous rocks of widely different ages occur 

 ai in the southern part of the province. On both sides of the great 

 central Carboniferous basin there appears to have been several periods 

 cf volcanic activit}'-, which developed chiefly along two lines, one of 

 them, the more southerly, extending across the country north of the Bay 

 cf Fundy from the Maine boundary nearly to Northumberland strait, 

 the other from the Maine boundary in York county north-east across 

 the province to the Bay des Chaleurs, and reappearing on the south side 

 of Gaspé peninsula. 



