Foundation, Concrete and Earthquake Engineering

Formation of Andes (Tectonic Cause)

The Andes mountain range is the highest mountain range outside Asia. The highest peak, Aconcagua, rises to 6,962 m (22,840 ft) above sea level. The summit of Mount Chimborazo in the Ecuadorean Andes is the point on the Earth's surface most distant from its center, because of the equatorial bulge.

But the Andes are the world's longest exposed mountain range. They lie as a continuous chain of highland along the western coast of South America. The range is over 7,000 km (4,300 mi) long, 200 km (120 mi) to 700 km (430 mi) wide (widest between 18° to 20°S latitude), and of an average height of about 4,000 m (13,000 ft).

 The Andes are the result of plate tectonics processes, caused by the subduction of oceanic crust beneath the South American plate. The main cause of the rise of the Andes is the compression of western rim of the South American Plate due to the subduction of Nazca Plate and the Antarctic Plate.

Satellite image of the southern Andes  The formation of the modern Andes began in the Jurassic Period. It was during the Cretaceous Period that the Andes began to take their present form, by the uplifting, faulting and folding of sedimentary and metamorphic rocks of the ancient cratons to the east. Tectonic forces along the subduction zone along the entire west coast of South America where the Nazca Plate and a part of the Antarctic Plate are sliding beneath the South American Plate continue to produce an ongoing orogenic event resulting in minor to major earthquakes and volcanic eruptions to this day. In the extreme south a major transform fault separates Tierra del Fuego from the small Scotia Plate. Across the 1,000 km (620 mi) wide Drake Passage lie the mountains of the Antarctic Peninsula south of the Scotia Plate which appear to be a continuation of the Andes chain.
Andes Mountain rang (portion of the Andes between Argentina and Chile)

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