NCEA Level 1 Geology: The Rock cycle and erosion and transport by glaciers
NCEA Level 1 Geology: The Rock cycle and erosion and transport by glaciers
As the glacier rips rocks away from the sides of the valley it can leave a polished surface with gouge marks. 400 years in this grinding machine can turn rocks into flour.Glaciers move slowly but relentlessly down valleys gouging out huge volumes of rock as they go. It takes about 400 years for snow collecting at the top of Fox glacier to reach the Fox river at the bottom.
As the glacier rips rocks away from the sides of the valley it can leave a polished surface with gouge marks. 400 years in this grinding machine can turn rocks into flour. Look at the colour of the water coming out the end of the glacier in the last video. Rocks carried by the glacier get dumped at the front and the sides when the ice melts.
Valleys formed by glacier erosion have a characteristic U shape.