Parr V. Srcr. i. § 2.) PLEISTOCENE. | 899 
Inter-glacial beds. Gravels, lignites, and clays of Utznach, Diirnten, &c. 
covered by the moraine stuff of the second glaciation and overlying the 
_ oldest glacial deposits—EHlephas antiquus, Rhinoceros leptorhinus. 
First glaciation. Striated blocks found under the inter-glacial beds. 
North America.—tThe general succession of events in post-Tertiary 
times appears to have been nearly the same over the northern hemi- 
sphere both in the New and the Old World. In North America we have 
the same sharply-defined line between the older post-Tertiary deposits 
and previous formations, due to the glacial conditions which, overspread- 
ing these regions, in great measure destroyed the superficial accumula- 
tions of the immediately preceding eras. The Quaternary or post- 
Tertiary formations are grouped by American geologists in the following 
- subdivisions : 
3. Recent and{Peat, alluvium, blown sand, “alkali” deposits, geyser deposits, 
Prehistoric\ cave deposits, artificial mounds. 
. {River-, lake-, and sea-terraces, loess. 
2. Champlain fee: sand, Champlain clays, Leda clay. 
1. Glacial.... . Boulder-clays, unstratified clays, sands, and gravels. 
1. Glacial.—As in northern Europe, the rocks underneath the glacial 
deposits of North America are well ice-worn. The direction of the strie 
is generally southward, varying to south-east and south-west according 
to the form of the ground. ‘The great thickness of the ice-sheet is 
strikingly shown by the height to which some of the higher elevations 
are polished and striated. Thus the Catskill Mountains rising from the 
broad plain of the Hudson have been ground smooth and striated up to 
near their summits, or about 3000 feet, so that the ice must have been of 
even greater thickness than that. ‘The White Mountains are ice-worn 
even at a height of 5500 feet. As in Hurope, the glacial deposits increase 
in thickness and variety from south to north. The southern limit of the 
unstratified drift lies somewhere in the neighbourhood of the 39th 
parallel of north latitude, and the deposit ranges from the Atlantic 
westward to the meridian of 98°. It spreads, therefore, across Canada, 
and is found over a considerable area of the north-eastern States. I¢ 
rises to a height of 5800 feet among the White Mountains. The absence 
of any true boulder-drift on the Rocky Mountain slopes, where it might 
have been looked for, is remarkable, for these mountains once nourished 
large glaciers, which have left enormous piles of moraine stuff, and have 
strewn many hills with transported erratic blocks. There is likewise 
a tract south-west from Lake Michigan which has escaped the ice-sheets 
that elsewhere have covered the eastern parts of the States with detritus. 
The coarse unstratified drift or boulder-clay bears witness to a general 
- southerly transport of material, and, in conjunction with the striated 
rocks, shows that the great ice-sheet moved from north to south at least 
as far as about the latitude of Washington. Logan mentions that in some 
parts of Canada the glacial drift and boulders run in ridges noith and 
south, thus corresponding with the general direction of transport, like 
the “drums” in Britain. As in Europe, the coarse boulder-clay at the 
base is essentially unfossiliferous. 
2. Champlain.—Under this name have been classed the loose deposits 
or drifts overlying the lower unstratified boulder-clay, and belonging to 
the period of the melting of the great ice-sheets, when large oe of 
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