EAMSAY DEIFT-PEEIOD OF CANADA. 211 



the conditions for such a result heen alike propitious. But the 

 evidence is opposed to any such conclusions. I saw no well-marked 

 roches moutonnees, no traces of moraines ; and the forest-clad slopes 

 are mostly covered with deep local gravel and boulder-drift, many of 

 the stones in which are scratched. Had a glacier existed there siace 

 the drift-period, the drift would have been ploughed out of the 

 valley by the glacier, in the manner that it was removed by the gla- 

 ciers of the Passes of Llanberis and Nant Prancon in North Wales ; 

 whereas nothing has been removed, except a portion of the drift by 

 the torrent that now flows in the bottom* (see fig. 4). 



Probable equivalency of the Drift of the Hudson Valley with that 

 of LaJce Champlain and of Montreal. — I have now a few remarks to 

 offer on a part of the drift itself. South of Albany the Hudson 

 flows through a broad valley full of minor undulations, between the 

 Catskill and the Green Mountaras. On the banks of the river are 

 extensive beds of sandy clay, from which the bricks are made of 

 which Albany is built. The city stands on this clay, which extends 

 far dovm the river towards IS'ew York, and northward iato the Yalley 

 of the Mohawk, and as I shall show, probably also into the valley of 

 Lake Champlain. Beyond the river-bank it stretches E. and W. on 

 the undulating ground towards the mountains, rising, six miles in the 

 direction of the Helderberg, far above the level of the river. At its 

 edge, Mr. Hall poiated out to me that the sands, gravels, and boulder- 

 clay of the ordinary drift pass under it. The superficial deposits of 

 the valley of the Hudson, therefore, consist of two subdivisions: 

 first, the older boulder-beds ; and, second, the laminated clay, which 

 at Albany is a thick formation, finely and evenly bedded in layers of 

 1 or 2 inches thick, the argillo-arenaceous laminse of which graduate 

 into each other in shades of bluish-grey, brown, and brownish- 

 yellow, producing a beautifully ribanded aspect, and giving the im- 

 pression of a succession of repeated alternations of tranquil deposi- 

 tions in still water. Boulders occur in it rarely ; and the top is 

 covered with sand, which may possibly represent the uppermost 

 sandy beds of the St. Lawrence and Ottawa districts. I searched 

 in vain for fossils, both in the paper-like laminae of clay, and in the 

 abimdant concretions, resembling those of the valley of ^he Ottawa 

 which contain the fossil fish Mallotus villosus. 



The Hudson runs nearly straight north and south ; and forty miles 

 above Albany, at Sandy Hill, the Champlain Canal joins the river to 

 Lake Champlain, which also trends north and south, and, separated 

 by a low watershed, lies in what must be considered a continuation 

 of the valley of the Hudson. The lake is 90 feet above the level of 

 the sea ; and on the Vermont shore, 150 feet above the sea, there is 

 a section of six feet and a half of regularly stratified clay and sand, 

 overlying an older blue clay (the older drift), in which were found, 

 by Professor Zadoc Thompson, Sanguinolaria fusca, My a arenaria, 



* I was informed by Professor Agassiz, that in the White Mountains, which 

 rise more than 6000 feet above the sea, there are in the liigher regions distinct 

 indications of ancient glaciers ; and if this be the case, the same phenomena may 

 be looked for in the mountains of Gaspe. 



