1. Till: This is unsorted, unstratified material deposited directly by the glacier. It can include a wide range of sizes, from fine clay to large boulders, with everything in between. Till deposits are characteristically poorly sorted and angular, reflecting the glacial process of grinding and transporting rocks.
2. Stratified drift: This consists of materials that have been sorted and layered by meltwater flowing from the glacier. It typically includes:
* Outwash: Well-sorted, stratified sand and gravel deposited by meltwater streams flowing away from the glacier.
* Kames: Conical hills of sand and gravel deposited by meltwater streams in depressions on the glacier surface.
* Eskers: Long, winding ridges of sand and gravel deposited in the channels of meltwater streams flowing beneath the glacier.
* Lacustrine deposits: Fine-grained sediments deposited in glacial lakes formed by meltwater.
Types of glacial drift and their features:
| Type of drift | Features |
|---|---|
| Till | Unsorted, unstratified, angular, poorly sorted, contains a wide range of particle sizes |
| Outwash | Well-sorted, stratified, rounded, layered, typically sandy or gravelly |
| Kames | Conical hills, composed of sand and gravel, often found near the edge of former glaciers |
| Eskers | Long, winding ridges, composed of sand and gravel, typically found in valleys |
| Lacustrine deposits | Fine-grained sediments, often clay or silt, deposited in glacial lakes |
Importance of glacial drift:
Glacial drift plays a significant role in shaping the landscape and influencing soil formation. It creates diverse landforms like moraines, drumlins, and kettles. The materials deposited by glaciers provide valuable resources for agriculture, construction, and groundwater storage.
Note: The term "glacial drift" is sometimes used synonymously with "glacial deposit" but it's more accurately used to encompass all materials transported by glaciers, including those that are still being transported.
