Roche moutonnée

Roche moutonnée below Myot Hill - geograph.org.uk - 164736

A roches moutonnees surface

Roche moutonnée eng text

Oblique view of roches moutonnees surface at Great Slave Lake, Nunavut, Canada

Roche moutonnée (from the French for "fleecy rock") is a geological formation created by the erosive action of glaciers. These formations are characterized by their asymmetrical shape, with a smooth, gently sloping side and a steep, rough side. The term is often used in glaciology and geomorphology to describe these distinctive landforms.

Formation

Roche moutonnée forms as a result of the movement of a glacier over bedrock. The glacier exerts pressure on the rock, causing it to erode. The side of the rock facing the direction of the glacier's advance is smoothed and polished by the abrasive action of the ice and the debris it carries. This side is known as the stoss side. The opposite side, known as the lee side, is typically rough and steep, formed by plucking and quarrying as the glacier moves away, pulling pieces of rock with it.

Characteristics

Roche moutonnée can vary in size from a few meters to several hundred meters in length. The smooth stoss side often shows striations, which are linear grooves carved into the rock by the movement of the glacier. The lee side, in contrast, is jagged and irregular, reflecting the fracturing and removal of rock material.

Significance

Roche moutonnée provides important clues about the direction of glacier movement and the dynamics of glacial erosion. These formations are valuable to scientists studying past glacial periods and the processes that shape the Earth's surface.

Examples

Notable examples of roche moutonnée can be found in many glaciated regions around the world, including the Scottish Highlands, the Alps, and parts of North America.

Related Pages

• Glacier
• Glacial erosion
• Striation (geology)
• Plucking (glaciation)
• Geomorphology
• Glaciology

See Also

• Cirque
• Arête
• Horn (geology)
• U-shaped valley