SUPPOSED EVIDENCES OF SUBSIDENCE OF NEW BRUNSWICK COAST. 53 
oldest and, therefore, lowest parts, while their outer parts have 
been more or less eroded by the advancing ocean .” 1 Thus it 
is conceived that barrier beaches originate as true beaches at 
the mouths of rivers on a low coast; that as this coast sinks 
beneath the sea, the river mouths are drowned to form lagoons, 
while the beaches, being tied to headlands at either end, remain 
relatively fixed in position; that as soon as the subsidence allows 
the sea a better opportunity to cut the beach away from its 
supporting headlands, there is a rapid widening of gullies, and 
a conversion of the reef into a broken chain of sand islands. 
It will be noticed, by those familiar with the commonly 
accepted principles of shore-line morphology 2 that the first or 
“rudimentary stage, as outlined above, is the final stage, 
according to the accepted theory. Barrier beaches along coasts 
like that of New Brunswick are commonly believed to owe 
their origin to a rapid accumulation of shore drift along the 
concave line of breakers between headlands, and to follow these 
retreating headlands in their shoreward migration, narrowing 
the lagoons as they go, until at last they reach the mainland, 
and the lagoons vanish, so that the barrier passes into a true 
beach. In other words, the small beaches which Professor 
Ganong regards as “ forming ” would be regarded by most 
physiographers as disappearing barrier beaches. It is perhaps 
sufficient reason for the rejection of this theory of subsidence in 
favour of the commonly accepted one, that long bars or barriers 
of this kind occur between headlands on lakes whose level has 
been unvarying. Moreover, since both the headlands and the 
beaches, on the New Brunswick coast, are known to have been 
rapidly retreating, during the last few centuries, at least, this 
horizontal shifting, alone, of the sand reefs towards the shore, 
is competent to account for the several stages of development 
noted, if the long barriers which bridge the greater re-entrants 
are taken as the more youthful type, and the short beaches at 
the mouths of streams on the most exposed headlands mark 
the end of the life history of the barriers. Here, as in the case 
of the rapid recession of sea-cliffs, we find no necessity for 
progressive coastal subsidence. 
1 Op. cit., p. 5. 
8 See, for instance, W. M. Davis; Physical Geography. Boston, 1899, pp. 353-354. 
