Soche is a dacitic

volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

and is located on the northern end of a secondary volcanic chain. Constructed on a

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

substratum, it contains an eastwards-opening

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 ...

in the summit region. A large eruption in 6650 BCE generated ashfall into

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

and two lava domes in the caldera. The ash- and

lapilli Lapilli is a size classification of tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts. ''Lapilli'' (singular: ''lapillus'') is Latin for "little stones". By definition lapilli range f ...

-fall is about a metre thick in the Interandean valley and the neighbouring cordilleras and most likely represented a long-lasting obstacle for human population. Earlier eruptive events involving a lava flow that was subsequently offset by a fault zone named the Cayambe-Chingual fault by 110m occurred 9.67 ka BP, and another involving a pyroclastic flow was dated at 37.22 ± 0.63 ka BP.

References

Volcanoes of Ecuador Andean Volcanic Belt VEI-5 volcanoes Inactive volcanoes {{Volcano-stub