The Zagros Mountains in southwestern Iran present an impressive landscape of long linear ridges and valleys. Formed by collision of the Eurasian and Arabian tectonic plates, the ridges and valleys extend hundreds of kilometers. Stresses induced in the Earth’s crust by the collision caused extensive folding of the preexisting layered sedimentary rocks. Subsequent erosion removed softer rocks, such as mudstone and siltstone while leaving harder rocks, such as limestone and dolomite. This differential erosion formed the linear ridges of the Zagros Mountains. This astronaut photograph of the southwestern edge of the Zagros mountain belt includes another common feature of the region—a salt dome (Kuh-e-Namak or “mountain of salt” in Farsi).
Published Apr 17, 2006
A long valley reveals the location of the Enriquillo-Plaintain Garden Fault in southern Haiti, the site of a deadly earthquake in mid-January 2010.
Published Jan 14, 2010
These colorful sequences of rock tell a story of geologic upheaval.
Published Jan 25, 2017
Where the Pacific plate and North American plate meet, the intense pressure of the collision creates an 800-mile-long fracture zone.
Published Jun 23, 2009
