Volcanoes
of the Andes Mountains
During the formation of the Andes Mountains, approximately
170 million years ago, the Nazca plate and Antarctic plate subducted under the
South American Plate. That is when one tectonic plate moves under another,
sinking into the mantle as they converge. This convergence caused magma from the
mantle to solidify underground becoming an extrusive igneous form. Thus
creating minerals that would become valuable to the natives who lived near the
Mountains. Volcanic arcs also formed from the movement of the plates along the
western edge of the South American Plate, which resulted in numerous volcano
formations throughout the Andes Mountains.
Andean Volcanic Belt
The Andean volcanic belt formed along the Andean
Cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador and Peru. These
volcanic formations are divided into four zones, Northern, Central, Southern,
and Austral. The Northern zone extends from Colombia to Ecuador, while the
Central zone extends from Peru to Chile. The Central volcanic zone is known for
its continental crust that has reached a thickness of 70km, which is made up of
igneous, sedimentary, and metamorphic rocks. The Southern zone extends from the
central Chile Andes to Santiago, Cerro Arenales located in the Aysen Region of
Chile. The Austral zone extends south of the Patagonian volcanic gap to Tierra
de Fuego, Archipelago and is made up of alkaline, basalt and basanite. It also consists
of composite volcanoes that are built by layers of lava flow and subglacial
volcanoes, volcanoes formed beneath a glacier or ice sheet.
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| The Andean volcanic belt within the Andes Mountains and the major volcanoes located in Ecuador. |
Volcanoes
in Ecuador
There are fifty-five volcanoes that are located in
Ecuador and nineteen more located in Colombia, which makes up the Northern
Volcanic Zone. The Cayambe volcano is located on one of the highest mountains
in the world measuring 5,790 meters at its highest point. It is classified as a
Holocene volcano made up of particles that come from basaltic silica, an
extrusive igneous rock. Another notable volcano located within the western Ecuadorian
Andes is Quilotoa, known for its three kilometer caldera. The caldera is the collapse
of the volcano within itself from lava spilling out of the magma chamber, thus
creating the crater. The water inside the crater is green because of the
minerals in volcanic ash (“Ecuador’s Avenue of Volcanoes”).  |
| Caldera of volcano Quilotoa. |
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| Formation of Caldera. |
There are many volcanoes in the Andes Mountains depicting
the various and unique changes that occur in volcanic formations.
Work Cited
https://www.revolvy.com/main/index.php?s=Andean%20Volcanic%20Belt
