THE SUCCESSION OF DEPOSITS. 61 



From the nature of the Saxicava sand, it is obvious 

 that it is for the most part a shallow-water deposit, 

 belonging to the period of emergence of the land ; and it 

 must liave been originally a marginal and bank deposit, 

 depending nnich for its distribution on the movement of 

 tides and currents. In some instances, as at Cote des 

 N'eiges, near Montreal, and on the terraces on the lower 

 St. Lawrence, it is obviously merely a shore sand and 

 gravel, like that of the modern beach. Ridges of Saxi- 

 cava sand and gravel have often been mistaken for 

 moraines of glaciers; but they can generally be distin- 

 guished by their stratified character and the occasional 

 presence of animal remains, as well as by the water-worn 

 rather than glaciated appearance of their stones and 

 pebbles. In this connection, however, it must be observed 

 that it is not possible to distinguish the high-level beaches 

 and deposits of superficial travelled boulders from the 

 Saxicava sand. In otlier words, ichile the Saxicava sands 

 and gravels may he shallow-iuater deposits, they must, when 

 at high levels, have been formed on the margins of deep seas. 

 This is a most important 'fact in connection with the 

 upper or later boulder deposit. 



The Saxicava sand sometimes rests on the Leda clay or 

 boulder-clay, and sometimes directly on the rock, and the 

 latter is often striated below this deposit ; but in this 

 case there is generally reason to believe that boulder-clay 

 has been removed by denudation. It is to be observed, how- 

 ever, that the typical Saxicava sand and the upper or newer 

 boulder-drift belong to the same period of submergence. 



4. — Terraces and Inland Sea Cliffs, and Kaims. 



These are closely connected with the deposits last 

 mentioned, inasmuch as they have been formed by the 



