Glacial Landscapes in the UKDeep Dive
The Big Picture: Erosional vs Depositional
This deep dive covers The Big Picture: Erosional vs Depositional within Glacial Landforms for GCSE Geography. Revise Glacial Landforms in Glacial Landscapes in the UK for GCSE Geography with 17 exam-style questions and 20 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 2 of 16 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 2 of 16
Practice
17 questions
Recall
20 flashcards
❄️ The Big Picture: Erosional vs Depositional
Before diving into individual landforms, it helps to understand the fundamental division that underpins the whole topic:
Erosional landforms — upland areas — carved by the glacier itself
As the glacier moves, it erodes the bedrock beneath and around it using two processes: abrasion (grinding with embedded rock fragments — like sandpaper) and plucking (ice freezing onto bedrock and ripping chunks away). The products are the dramatic upland features: corries, arêtes, pyramidal peaks, U-shaped valleys, hanging valleys, truncated spurs, and ribbon lakes. These are found in mountainous areas such as Snowdonia, the Lake District, and the Scottish Highlands.
As the glacier moves, it erodes the bedrock beneath and around it using two processes: abrasion (grinding with embedded rock fragments — like sandpaper) and plucking (ice freezing onto bedrock and ripping chunks away). The products are the dramatic upland features: corries, arêtes, pyramidal peaks, U-shaped valleys, hanging valleys, truncated spurs, and ribbon lakes. These are found in mountainous areas such as Snowdonia, the Lake District, and the Scottish Highlands.
Depositional landforms — upland and lowland areas — built by material dropped by the glacier
As the glacier slows, melts, or stagnates, it drops the material it has been carrying. This material — called till — is a jumbled mixture of rock particles of all sizes (unsorted). The depositional landforms include drumlins, erratics, and moraines in upland valleys, and outwash plains, kettle holes, and eskers in lowland areas ahead of the former glacier snout.
As the glacier slows, melts, or stagnates, it drops the material it has been carrying. This material — called till — is a jumbled mixture of rock particles of all sizes (unsorted). The depositional landforms include drumlins, erratics, and moraines in upland valleys, and outwash plains, kettle holes, and eskers in lowland areas ahead of the former glacier snout.
Post-glacial landscape features
After the ice retreats, rivers and streams reoccupy the landscape. But the valleys are far too large for the rivers that flow through them — these tiny rivers are called misfit streams. Corrie hollows fill with meltwater to become tarns. Glacial troughs fill with lakes (ribbon lakes). The landscape left behind tells the story of the ice age in stone and water.
After the ice retreats, rivers and streams reoccupy the landscape. But the valleys are far too large for the rivers that flow through them — these tiny rivers are called misfit streams. Corrie hollows fill with meltwater to become tarns. Glacial troughs fill with lakes (ribbon lakes). The landscape left behind tells the story of the ice age in stone and water.