Secrets of the Alps
Part of Hall of Planet Earth.
Part of Hall of Planet Earth.
The inner structure of a mountain belt is revealed in the deeply eroded valleys of the Alps. Among the outstanding features are the exposures of enormous, flat-lying folds called nappes. The alpine nappes formed as continental crust was compressed during the collision of the European and African plates. Their edges piled on top of each other, one gigantic fold overriding another, to be bent back and refolded again. The rocks are so contorted that 19th-century aesthetes closed the blinds of their carriages to block from view the disturbing lack of order in nature. But the study of the Alps has had a profound influence on geological thought.