roche moutonnée
Ice-sculpted bedrock hill
A roche moutonnée is a rock formation shaped by glacial movement—smooth and gently sloping on the side the glacier approached, rough and steep on the opposite side where ice plucked away chunks.
The term is French for "fleecy rock," from the resemblance to a sheep's back.
Geologists use these asymmetrical outcrops to determine which direction ancient glaciers flowed.
Slow-moving ice mass
- abrasionShallow surface wound
- pluckingRemoving by tugging
- quarryingOpen-pit stone mining
- ice flowDrifting frozen mass
erosion · striations · polish · lee side · bedrock · subglacial · glacial erosion · scouring
Not equal on both sides
- streamlinedMade smooth and efficient
- smoothWithout roughness or difficulty
- roundedHaving no sharp angles
- steepRising at sharp angle
gentle slope · elongated · polished surface · striated · grooved · sculptured · undulating · hummocky
Ice-sculpted depression between peaks
Igneous rock, quartz-rich
- gneissFoliated metamorphic rock
- bedrockSolid stone underground
- crystallineClear, ordered, brilliant
- jointingCreating flush edges
fracture · mineralogy · igneous · metamorphic · schist · quartzite · hardness
Ancient glacial geological period
- ice ageEra of massive glaciation
- QuaternaryLast 2.6 million years
- deglaciationRetreat of glaciers
- HoloceneCurrent geological epoch
glacier
Slow-moving ice mass
ice flow · erosion · striations · polish · lee side · bedrock · subglacial · glacial erosion · scouring · ice sheet
asymmetrical
Not equal on both sides
- streamlinedMade smooth and efficient
- smoothWithout roughness or difficulty
- roundedHaving no sharp angles
steep · gentle slope · elongated · polished surface · striated · grooved · sculptured · undulating · hummocky · knob
glacial valley
Ice-sculpted depression between peaks
granite
Igneous rock, quartz-rich
- gneissFoliated metamorphic rock
- bedrockSolid stone underground
- crystallineClear, ordered, brilliant
jointing · fracture · mineralogy · igneous · metamorphic · schist · quartzite · hardness
Pleistocene
Ancient glacial geological period
- ice ageEra of massive glaciation
- QuaternaryLast 2.6 million years
- deglaciationRetreat of glaciers