⚙️ how
How do roches moutonnées form beneath glaciers?
GeologyGlacial landforms
Quick Answer
A moving glacier smooths the rock on its upstream side by abrasion and plucks blocks from the downstream side. This creates a rounded hump with a steeper lee slope.
The Full Story
Roches moutonnées are asymmetrical bedrock hills shaped by ice flow. On the side facing the approaching glacier, rock is polished and smoothed as sand and stones in the ice grind over it. On the downstream side, pressure drops and blocks are plucked away, leaving a steeper, rougher face. These features are useful clues for reconstructing the direction of ancient ice movement.
Key Facts
1.Upstream side is smoothed by abrasion
2.Downstream side is steepened by plucking
3.They reveal the direction of glacier flow
YouTube Angle
Suggested video title for this topic:
"How can a glacier sculpt a rock into a one-way hill?"