[PENHALLOW] DEVELOPMENT OF CERTAIN MARSH LANDS 19 
width ;” and he continues in some detail to show that not only were 
prominent localities like Coney Island, Gardener’s and Plum Islands, 
and the high ground near the two light houses on Staten Island, being 
worn away by the action of the surf, but that shell heaps which must 
have been formed some distance from the water, were being cut into 
and carried away. At Peacock’s point which was found to be wearing 
away, stumps and fallen trees were to be observed below low water mark, 
and the erosion at Kidd’s point was progressing so rapidly as to justify 
the statement that “A century or two would suffice for its entire 
removal.” 
In 18”8 Sir William Dawson directed attention to the occurrence 
of similar phenomena in the Maritime Provinces of Canada. He 
likewise concluded that there had been a decided depression of the 
sunface because of the extensive silting up of shallow basins and the sub- 
mergence of forests which he describes as occurring in Nova Scotia and 
elsewhere (3, 29-30). Such torests are somewhat general throughout 
the marsh country, and “ There is little reason to doubt that the whole 
- of the Cumberland marshes rest on old upland surfaces.” The con- 
clusion reached by him is to the effect that the submergence was due 
to a depression of the general area to the extent of forty feet, and he 
further quotes the conclusions of Gesner in 1861, to the effect that such 
subsidence was very general over the entire area of the Maritime 
Provinces, and that there is undoubted evidence of subsidence since 
European colonization. 
Other and more recent evidence of a somewhat varied character 
also gives undoubted support to the view that, not only has there been 
a marked depression of Nova Scotia and adjacent areas in the-past, but 
there is a present continuation of such subsidence. 
The dyked lands of the Annapolis valley, although maintained as 
such for more than two hundred and fifty years, nevertheless show that 
there is a slow but perceptible encroachment of the sea which necessi- 
tates raising the dykes from time to time. The land within the dykes 
is in many places lower than the external areas, and much difficulty is 
experienced in keeping the land clear of water. Indeed, the very 
formation of these fertile lands is proof of the subsidence of the area 
in which they lie, and the thickness of the deposit is a partial measure 
of the extent of such depression. These lands were not formed by the 
ordinary process of marsh growth, but as the result of a gradual silting 
up of a shallow interior basin by the deposition of material brought in 
by tidal waters, and their development affords conclusive evidence of 
Sec. IV., 1907. 
