The Matternhorn - the massive, distinctive peak that marks the Swiss-Italian border in the Alps - is important not just to climbers but also to geologists. The Matternhorn's pyramidal peak is a textbook example of the effects of glacial erosion. The mountain is also living evidence of the theory of plate tectonics, since it is formed from Apulian rock material which originated in the continent of Africa.
Writing in "Scrambles Amongst the Alps" almost a century and a half ago, the famous alpine climber and amateur scientist Horace-Benedict de Saussure remarked that an unimaginably awesome power "must have been required to shatter and to sweep away the missing parts of this pyramid." Saussure could not have imagined that he had nearly stumbled upon one of the key parts of the modern theory of glaciation.
According to professor of geology Grenville Draper of Florida International University, "nearly all rugged mountain landscapes show evidence of glaciation." The Swiss Alps are no exception. When several glacial cirques form on different sides of a mountain, they gradually erode away the surface of the mountain itself, literally grinding and whittling it away into a distinctive pyramidal peak called a "glacial horn."
The Matterhorn is the most distinctive example of a glacial horn in Europe, and one of the most important examples of this type of landform in the world. Mount Everest also has a distinctive pyramidal horn. In the case of the Matterhorn, this formation was probably created over the course of ice ages during the last million years. When it first formed, the Matterhorn would have had a much more hill-like and nondescript shape.
The Matterhorn is also important to geology because of the processes which it illustrates over an even longer term. According to modern plate tectonics theory, Earth's surface is actually continually in motion. Seafloors spread. Continents appear to "drift" across the face of the planet. None of this is easily perceptible to human beings - Jason Cross of Cochise College says that a "fast" velocity for a continent is a couple of inches per year. Over billions of years, however, Earth's continents have continually drifted apart, crashed together and broken apart again, altering into new shapes each time.
Once again, the Matterhorn offers distinctive evidence of these shifts - as do other types of ancient rock formations that have been relatively undisturbed for very long periods of time. The upper part of the Matterhorn, says professor Clark Johnson of the University of Wisconsin-Madison, is distinctively African in origin. Its rock comes from the Apulian fragment, which broke apart from Africa during the Cretaceous (about 100 million years ago) and eventually crashed into Europe along what are now the Alps.
The base of the Matterhorn, meanwhile, is quite a different rocky material. Johnson says that this part of the massive mountain is actually made up of what used to be the floor of the Tethys Ocean, the sea separating Gondwana (Antarctica, South America, Africa, India and Australia) and Laurasia (North America, Europe and Asia) as the last great supercontinent gradually broke up between 100 and 200 million years ago.