60 David Milne-Home on Ancient Glaciers. 
tation of the erratic blocks was characterised by the formation 
of the Molasse, a deposit which Agassiz has compared to the 
well-known Till of Scotland. Now this clay deposit in Swit- 
zerland consists of two beds, the lower bed containing fresh- 
water fossils, the upper bed containing marine remains ; which 
last fact implies submergence beneath the sea. Then it ap- 
pears from the researches of Professor Favre of Geneva, that 
since the deposition of these molasse beds there was an exten- 
sive upheaval of some of the mountains, and especially of the 
Saléve hills, on whose sides these molasse beds were deposited ; 
for instead of being horizontal, as they must originally have 
been, or at all events sloping at a low angle, these molasse 
deposits are in some places now inclined at angles from 35° 
to 45°, and at one place dip in opposite directions. 
Therefore, immediately antecedent to the transportation of 
the erratic blocks, this district sank beneath the sea, and sub- 
sequently rose up, dislocating these molasse beds—implying, 
therefore, an upheavel of the Western Alps. 
But it can also be shown, that, immediately after the same 
period, another depression of this region, and a submergence 
in deep waters, took place; for how else can those strati- 
fied beds of gravel, sand, and clay have been formed which 
now lie over the molasse, and which we have seen occur in all 
parts of Low Switzerland up to the height of 3000 feet and 
more above the present level of the sea? It is quite impossible 
to account for the formation of sand-hills and gravel-beds 
200 feet thick, composed of regular layers, mostly horizontal, 
except on the supposition of their having been formed in the 
waters of a sea, not subject to much violence, but agitated by 
ordinary tides and currents. 
I infer that this depression and submergence took place at 
a period posterior to the transportation of the erratic blocks, 
because these blocks (as I have shown) are in many instances 
enveloped in the heart of the stratified beds. 
Then this submergence was followed by a re-elevation of 
the country to its present levels. 
Thus, immediately before the transportation of the blocks, 
the country was successively depressed and elevated; and 
immediately after that event these operations were repeated, 
