384 



northward from the end of the same lake, exposures of 

 granite alternate with others of diorite, diabase, quartzite 

 and various types of schists. Some of the diabase rocks 

 cut the granite, but the diorite and various types of schists 

 are probably all older than the granite. 



SUSPENSION BRIDGE.* 



General Description. — At the locality known as 

 Suspension bridge, the St. John river is spanned by two 

 bridges — a railway bridge and a highway bridge. At this 

 point the river is confined for about 300 feet (90 m.) to a 

 gorge-like channel about 300 feet (90 m.) wide through 

 which the waters rush in a southerly direction. Below 

 this point the river channel suddenly widens, abruptly 

 turns to the northeast, and follows this course for about 

 one mile, to the head of St. John harbour. Above the 

 constricted channel at the bridges, the river widens and 

 about 500 yards (460 m.) farther up, again contracts. 

 Above the second constriction, known as the "upper falls", 

 the river widens to lake-like dimensions and after abruptly 

 bending to the northwest continues with this character 

 for many miles. A long arm of this lake extends to the 

 northeast and this arm together with the northwesterly 

 extending lake-like expansion of the St. John river is 

 known as Kennebecasis lake. 



The lake bottom is very irregular, with deep channels in 

 which the water reaches depths of between 100 feet and 

 200 feet (30 m. to 60 m.). At the constriction known as 

 the upper falls, the water is only about 25 feet (7-5 m.) 

 deep. Below this point the channel is deep; even in the 

 gorge-like portion at Suspension bridge, the water is 100 

 feet (30 m.) deep but at the exit from the short gorge at 

 the lower falls, the water shoals to a depth of about 25 

 feet (7-5 m.). In the channel-way below Suspension 

 bridge as far as Navy island at the head of St. John Har- 

 bour, the depth of the water varies between 30 feet and 

 100 feet (9 m. and 30 m.). 



The waters of Kennebecasis lake, though in direct 

 communication with the sea, always stand above mean 

 tide level. In the spring of the year, the waters of the 

 lake lie at a height of 9 feet (2 • 75 m.) or more above mean 

 tide ; later in the year as the volume of fresh water draining 



*See Map — Suspension Bridge. 



