These
rocks either fell onto the glacier surface in the Alps or were scooped
up from the ground by the ice and transported down into the valley.
These boulders provide evidence that the alpine foreland was once
almost entirely covered by glaciers. In Lucerne itself the ice was
almost 1,000 metres thick. The large, light-colored granite boulder
from the Gotthard region weighs 5 tons.
The glacier
carries a boulder downhill.
Erratic
blocks from
the Central Alps.
Fossilised
oyster shells in an erratic boulder found in canton Uri.
