332 A. C. Ramsay on the Glacial origin of certain Lakes 
diately under the Seidelhorn, one for the lake at the Grimsel, 
another for the drained lake at the Kirchet,’ and another for 
the lakes of Brienz and Thun. In Sutherlandshire these areas 
of special subsidence would be required by the hundred, and in 
North America by the thousand, 
Signor Gastaldi, in a masterly memoir on the composition of 
the Miocene conglomerates of Piedmont,’ considers with reason 
that the large angular blocks of these strata, many of them far- 
transported, and some of them foreign to the Alps and Apen- 
nines, have been deposited from ice-rafts; and thence he infers 
the existence of glaciers during a part of the Miocene epoch. 
But, admitting this, it is evident that the distribution of the 
Post-pliocene glaciers of the Alps must, in all details, have been 
quite different from those of Miocene age, in consequence of the 
great disturbance that the Alpine rocks underwent after the close 
of the Miocene epoch, and the subsequent formation of numerous 
new valleys of denudation. ‘T'races of the long lapse of time 
between the Miocene and the later Glacial epoch are in other 
countries but imperfectly preserved in the subdivisions of the 
Crag, and of other minor easel of still later date. Of the 
poe 
and during all the time that elapsed from the close of the —_ 
until the period of extreme cold came into action, the Alps 
above the sea, and suffering subaerial denudation, nee wid 
being formed and deepened. It is possible that, while the 
climates of the Lower Crag epochs endured, there may 8 ill ee 
been glaciers in the higher Alps; but at whatever period te 
later glaciers commenced, those who allow the extreme slowness” 
of geological change will admit that the period was —a 
that elapsed during the gradual increase of the glacieta ee 
in an epoch of intensest cold, the ice abutted on the Jura In © 
direction, in another spread far beyond the present area of : 
Lake of Constance, on on the south invaded the plains of Lom: 
bardy and Piedmont. During all that time, weather and re 
water were at work modifying the form of the ground um 
review. But, as I have already explained, these two agents 
were incapable of scooping out deep hollows surrounded 0B 
sides by rocks, and it therefore follows that the lakes ey 
eared after the decline of the glaciers left the aa 
country exposed approximately as we now see mee eo 
admit, what seems to me impossible, that fractures, fo a 
the close of the Miocene epoch, remained filled with water 
- ® See the “Old Glaciers of Switzerland and North Wales.” sn 
ae i conglomerati Mioceni del Piemonte, jee 
. 
