Today’s topic:
Learning objectives of today.
1. Define the term ‘glacial drift’.
2. Identify two basic kinds of glacial drift.
Glacial drift
The glacial drift refers to all the varieties of rock debris that are deposited by glaciers at its terminus, where the ice melts.
There are two types of drift:
1. Stratified drift:
If meltwater streams adjacent to the ice, deposits layers of sorted and stratified clays, silts, sands, or gravels — they are called stratified drift.
2. Till:
It’s a kind of unstratified mixture of rock fragments, ranging in size from clay to boulders, that is deposited directly from the ice, without water transport.
In a nutshell, you can say, till is a heap of deposited materials by Glacier. When some tiny rock particles move from their initial place of glacial deposition by meltwater streams and deposit elsewhere in the layer (i.e., the tiniest particle is at the topmost layer) it becomes stratified drift. So, you can imagine, stratified drifts are usually found in lakes where meltwater streams terminate.