THE FORMER EXTENSION OF GLACIERS. 
133 
Glacial Deposits. 
Glacial deposits may be classed under two 
heads: — 
1. Moraines. 
2. Glacial deposits which have been rearranged 
by water and may be termed fluvio-glacial. 
Moraines are characterised by the presence of 
polished and striated pebbles, intermixed with more 
or less angular fragments, often coming from a great 
distance and yet not rolled, irregularly deposited in 
sand and mud, which, however, is not stratified. 
Fluvio-glacial deposits are composed of the same 
materials, but more or less rolled, and rearranged by 
water, like river gravels. They are glacial deposits 
caught up and carried to a greater or less distance 
by water. 
These two deposits are in intimate relation; they 
agree in their composition, and differ only as regards 
stratification. The fluvio-glacial beds, as we come 
nearer and nearer to their source, are composed of 
larger and more angular pebbles, while the stratifica- 
tion becomes less and less regular, so that they ap- 
proximate more and more to the character of true 
moraine. 
