SECTION IV., 1882. [281 | Trans. Roy. Soc. CANADA. 
ABSTRACTS 1882-83. 
I.—On the Physical and Geological History of the St. John River, New Brunswick. 
By L. W. Barury, MA, Ph. D. 
(Read May 26, 1882.) 
The main purpose of this paper was to call attention to a few facts connected with 
the physical and geological structure of the St. John-River valle y,as bearing upon its 
origin and history ; and especially as helping to show, what has been hitherto recognized 
in but few instances, that not only do our larger rivers, more particularly in the older 
portions of the continent, owe their present features to causes often of very remote origin, 
but that they were themselves in existence, in part at least, at very early periods. 
Referring first to its present aspect, the course of the St. John in relation to the 
physical features of the region traversed, was pointed out as necessarily determined by 
conditions different from those which now exist ; that course, for some three hundred miles 
of its length, taking place apparently irrespectively of the present irregularities of surface ; 
being at right angles, or nearly so, to the present feature-lines of the country, and inter- 
secting, in the distance named, not less than five great axes of elevation, and at least eight 
distinct geological formations. In three if not four instances these axes still afford suffi- 
cient resistance to produce more or less considerable falls, viz.: Little Falls, Grand Falls 
(100-150 feet), Meductic Falls, now artificially reduced to rapids, and the falls beneath 
the suspension-bridge at the mouth of the river. It is in connection with these falls and 
the transverse gorges which accompany them, that we meet with the most interesting 
facts illustrative of the river’s history. 
In the case of the falls at the outlet, long known, from its relations to the tides of the 
Bay of Fundy, as constituting a unique feature in the structure of the river, the facts 
observed are especially important. Produced where the waters of the river, previously 
occupying a channel remarkable for its extent and depth, become abruptly confined to a 
narrow gorge, this fall has its immediate origin in a band of pre-Cambrian rock crossing 
the stream, obliquely and forming a barrier, over which the waters of the river and of the 
bay flow alternately. From the relative levels of the harbour and river, and the known 
rise of the tide, the latter (varying from twenty-five to twenty-seven feet), it would appear 
that the inward fall over the barrier at the suspension bridge is from nine to ten feet ; but 
as this inward fall is wholly confined to the last third of the flood-tide, attaining its 
maximum with the latter, and again rapidly receding, the interval during which the river 
is effectively resisted is greatly limited, not exceeding three or four hours out of every 
twelve. 
Sec. IV., 1882-83 36. 
