Plucking
Also called: Quarrying · Topic: Landforms and their Evolution: Rivers, Groundwater, Glaciers, Waves and Wind · NCERT: Class 11, Ch 6 "Landforms and their Evolution"
Meaning
Plucking, also called quarrying, is a way that glaciers erode rock. Meltwater seeps into cracks and joints in the bedrock and freezes there, so the ice becomes stuck to the rock. As the glacier moves on, it pulls out large angular blocks of rock. These blocks are then carried in the ice and scrape the valley floor and sides. This scraping is called abrasion. Plucking and abrasion together let glaciers reduce mountains to low hills and plains.
Example
In the Himalaya of Uttarakhand, valley glaciers such as the Gangotri glacier loosen angular rock blocks by plucking. Some of these blocks end up in the piles of debris near its snout at Gaumukh.
Don't confuse with
- Abrasion: the ice and the rock pieces it carries grind and scratch the rock surface. In plucking, the ice tears whole blocks out of the bedrock.
Related concepts
- Glacier
- Valley glacier
- Continental glacier
- Cirque
- Tarn
- Horn
- Arete
- U-shaped valley
- Hanging valley
- Truncated spur