120 
boulder clay by the grounding of icebergs and pack ice in 
shallow waters over a temporarily submerged coast. From 
the occurrence of erratic Laurentian boulders on the summit 
of Mount Royal he argued, as late as 1893, that the entire 
mountain had been submerged. This put the minimum 
limit of submergence above 700 feet (213-3 m.), [3, p. 63]. 
The highest shell locality reported by Dawson was 560 
feet (170 m.) above the sea. In 1892 Baron deGeer, 
accompanied by Professor F. D. Adams, selected as the 
highest level of submergence a bench and cliff on the 
northwest side of the mountain behind Mount Royal 
cemetery. The altitude of this bench was given as about 
625 feet (190-5 m.) [2, pp 454-457]. DeGeer’s determina- 
tion has since been very generally accepted. 
During the last four years detailed studies for the 
Geological Survey of the records of marine submergence 
in the St. Lawrence valley have thrown new light upon 
features which may be expected on Mount Royal. The 
following points are important: 
(1) Transported boulders are of no value as an 
evidence of marine submergence. While they are plenti- 
fully scattered over the area which is known to have been 
submerged, they also occur at all altitudes above the level of 
submergence where they have been left by the continental 
of ice sheet. 
(2) In spite of statements to the contrary, wave cut 
benches and sea cliffs are almost unknown along the upper 
line of marine submergence in the St. Lawrence valley. 
From near Gaspe peninsula southwestward 400 miles 
(643-7 km.) to the Champlain valley, the upper marine 
limit is marked by weakly built bars of gravel and obscure 
beaches, never by strong cliffs. This is true even on 
the exposed headlands. Experience shows that it is 
a mistake to look for wave-cut benches. Evidently this 
coast was already rising from the sea when the ice first 
uncovered it, and the waves did not have opportunity 
to cut sharply into the shore. 
(3) Accurate measurements of altitude on the upper- 
most gravel beaches in the district between Quebec and 
Lake Champlain, including that portion of the old shoreline 
which lies 40 miles (64-4 km.) southeast of Mount Royal, 
points to the probability that the submergence on this 
mountain is between 500 and 600 feet(152-4 and 182-8 m.). 
