MICHAEL SZOENYI / SCIENCE PHOTO LIBRARY MICHAEL SZOENYI / SCIENCE PHOTO LIBRARY
Eroded glacial rock formation. Boulder (lower right) balanced on top of a column of moraine rock. This is part of the Pyramides d'Euseigne, in the Herens valley, Valais, Switzerland. The rocks are what is left of a large deposit of moraine (ground-up rock debris, lighter rock) and boulders (darker colour) left behind by a glacier retreating at the end of the last Ice Age some 10,000 years ago. The moraine consolidated into a concrete-like mix, but most of it has eroded away, except where it is protected by the more resistant rock of a boulder. The three columns at right have lost their boulders, and will be eroded more swiftly than the column that is still protected.
Model release not required. Property release not required.