PIA03369 Perspective View with Color-Coded Shaded Relief Central Panama

El Valle is a

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and peri ...

in central

Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Co ...

and is the easternmost volcano along the

Central American Volcanic Arc The Central American Volcanic Arc (often abbreviated to CAVA) is a chain of volcanoes which extends parallel to the Pacific coastline of the Central American Isthmus, from Mexico to Panama. This volcanic arc, which has a length of 1,100 kilom ...

which has been formed by the

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

of the

Nazca Plate The Nazca Plate or Nasca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the N ...

below

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

. Some time prior to 200,000 years ago, the volcano underwent a huge eruption event that caused the top of the volcano to collapse into the empty magma chamber below forming a large

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

. Several

lava dome In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions ...

s have developed inside the caldera since the collapse—forming Cerro Pajita, Cerro Gaital and Cerro Caracoral peaks. Prior to research in the early 1990s, it was thought that no active volcanism existed within Panama. But radioactive dates from El Valle show that the volcano last erupted as recently as 200,000 years ago. Work by de Boer et al. and Defant et al.Defant, M. J., Jackson, T. E., Drummond, M. S., de Boer, J. Z., Bellon, H., Feigenson, M. D., Maury, R. C., and Stewart, R.H., 1992, The geochemistry of young volcanism throughout western Panama and southeastern Costa Rica: An overview: J. Geol. Soc. Lond., v. 149, p. 569-579. of other volcanoes within Panama have shown that there are two episodes of volcanism—young (< 2.5 million years ago) and old (> 4.5 million years ago) groups. The young volcanism consists of adakites (slab melts) whereas the older volcanism appears to be normal calc-alkaline volcanism.

References

External links

Website of El Valle de Anton
Calderas of North America Mountains of Panama Pleistocene calderas Pleistocene stratovolcanoes Stratovolcanoes of Panama {{Coclé-geo-stub

See also

References

External links