Sacabaya
Encyclopedia
Sacabaya is a pyroclastic shield
Pyroclastic shield
In volcanology, a pyroclastic shield or terrestrial ignimbrite shield is an uncommon type of shield volcano. Unlike most shield volcanoes, pyroclastic shields are formed mostly of pyroclastic and highly explosive eruptions rather than relatively fluid basaltic lava issuing from vents or fissures on...

 in Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

. It is located on the Altiplano
Altiplano
The Altiplano , in west-central South America, where the Andes are at their widest, is the most extensive area of high plateau on Earth outside of Tibet...

 near to the Rio Lauca. The volcano is composed of ignimbrite
Ignimbrite
An ignimbrite is the deposit of a pyroclastic density current, or pyroclastic flow, a hot suspension of particles and gases that flows rapidly from a volcano, driven by a greater density than the surrounding atmosphere....

, which has formed a shield. The shield is capped by an area of vents which has many overlapping craters, and is elongated in shape. At the southern end lies the youngest of the craters. This crater has a lava dome
Lava dome
|250px|thumb|right|Image of the [[rhyolitic]] lava dome of [[Chaitén Volcano]] during its 2008–2009 eruption.In volcanology, a lava dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano...

 within it. The peak has fumarole
Fumarole
A fumarole is an opening in a planet's crust, often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide. The steam is created when superheated water turns to steam as its pressure drops when it emerges from...

s and its associated tephra
Tephra
200px|thumb|right|Tephra horizons in south-central [[Iceland]]. The thick and light coloured layer at center of the photo is [[rhyolitic]] tephra from [[Hekla]]....

deposits have been shaped into sand dunes by wind activity.
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