554 



CENOZOIC TIME. 



It is probable that nearly or quite the whole breadth of the conti- 

 nent was similarly depressed, and that its amount was greatest to the 

 north. We cannot account for the terraces of Lake Ontario by sup- 

 posing a damming of the St. Lawrence by ice ; for they are much 

 higher on the northern side of the lake than on the southern ; and the 

 terrace, nearly 500 feet above the St. Lawrence, which is shell-bearing 

 at Montreal, may be traced along at intervals to the northern borders 

 of the lake, proving unbroken communication at the time, and a vast 

 outflow of water. Admitting the submergence, and its increase in 

 amount northward, the inequality in the level of the terraces on the 

 north and south sides of a lake gives no difficulty. 



The subsidence, although so general, could not have been due to 

 any cause affecting the whole ocean ; for the difference in amount of 

 subsidence between Southern New England and the region of Mon- 

 treal, only 6^ degrees apart, was 450 feet, and between the coast of 

 Maine and Montreal, one degree apart, 275 feet. It was a change 

 affecting locally the earth's crust, and large portions at once, over the 

 higher latitudes. 



We hence learn that, in the Champlain era, salt waters spread over 

 a large coast-region of Maine, and up the St. Lawrence nearly to Lake 

 Ontario, and covered also Lake Champlain and its borders. This 

 great arm of the sea, full 500 feet deep at Montreal and 300 to 400 

 in Lake Champlain, was frequented by Whales and Seals, their re- 

 mains having been found near Montreal, and a large part of the skele- 

 ton of a Whale — Beluga Vermontana Thompson (Fig. 950) — having 

 been dug up on the borders of Lake Champlain, 60 feet above its 

 level, or 150 feet above that of the ocean. It appears, besides, that 

 Nova Scotia was, at the same time, an island, and that the cold Lab- 

 rador oceanic current crossed the present isthmus (now less than 20 

 feet above high tide at Cumberland basin) with a depth of water ex- 

 ceeding 350 feet, and thence flowed down the Bay of Fundy to the 

 coast of Maine and eastern Massachusetts, bringing with it the living 

 species of the Labrador seas. 



It has also to be borne in mind, that, as stated on p. 543, the greater 

 depression of the land to the north must have caused a diminished 

 pitch in the bed of southward flowing streams ; and that this would 

 have influenced largely the height and breadth and pitch of flood-level 

 and of flood-made depositions, and, also, the degree of fineness of the 

 deposits. It would have favored fine clayey depositions in many parts 

 of valleys, until the flood, with increased height, had quickened the 

 rate of flow. The bed of. the Hudson River at Albany is now at high- 

 tide level ; but in the Champlain period, judging from the depression 

 of Lake Champlain, it was nearly 150 feet below this. A study of the 



