250 ON THE GEOLOGY OP ST. JOHN. 



a ridge of land extending in a northeast direction through the 

 middle of the county. The hill and ridge are on the southern 

 anticlinal fold already alluded to. In the rear of Quaco the ridge 

 is composed in part of syenitic and granitic rocks, hut between 

 the hill and the harbour of St. John no rocks of greater age than 

 the trap beds of this group appear. 



The elevation consists of basaltic trap, and is flanked on each 

 side by beds of amygdaloid, trap-ash, and other products of vol- 

 canic origin, which also cover the crest of the anticlinal fold for 

 two or three miles west of the hill. The succession of strata is 

 best displayed on the south side of the hill where they succeed 

 each other in the following order : — Basaltic trap, unstratified, of 

 great thickness ; bedded basalt, amygdaloidal porphyry, bedded 

 basalt, hornblendic trap-ash, micaceous quartzite, vesicular trap-ash 

 slate ; thickness of the stratified deposits about 3000 feet. There 

 is also on this slope a volcanic conglomerate, viz., fragments of 

 trap rocks imbedded in trap-ash slate. The quartzite resembles 

 some of the finer beds at West Beach and Black River, and the 

 porphyry is that alluded to in Gesner's 3rd Report, p. 15. The 

 trap-ash slate is in many places full of irregular vesicles, the sides 

 of which are coated with minute crystals of quartz, calcite, and 

 specular iron. 



The great increase in bulk of the stratified traps, <fcc, at this 

 place, and the nucleus of basalt over which they are spread, seem 

 to indicate that it is one of those vents from which during the 

 Devonian period, lava, ashes, and fragments of rock were poured 

 forth and carried many miles to the westward. 



The outcrop of the lava beds can be traced trending away to 

 the north and west, till they cross the harbour at the southern 

 end of the city, and disappear in the post-pliocene gravels west of 

 St. John. 



On the north side Kennebeckasis valley is bordered by a range of 

 abrupt hills from 250 to 600 feet high, consisting of altered clay 

 slate and sandstone, with numerous beds of greenstone interstra- 

 tified, the whole series being much disturbed and usually vertical. 

 They may be the equivalents of the volcanic sediments described 

 above; but their outcrop is so straight for a distance of thirty 

 miles, that they may prove to be part of an older series brought 

 up by a fault. 



h. Sedimentary beds. 



On each side of Bloomsbury mountain, and separated from it 



