Chaitenia is a distinct fragment of Earth's crust in southern Chile. Rocks of Chaitenia represents an ancient

island arc Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle alon ...

that existed next to

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and g ...

which became eventually accreted to it. The accretion of Chaitenia to Patagonia occurred in the

Devonian period The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, w ...

(''c.'' 400-360

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago) ...

) as inferred from an event where rocks were put under pressure, deformed and heated dated to that period. After merging into Patagonia,

accretionary complex An accretionary wedge or accretionary prism forms from sediments accreted onto the non-subducting tectonic plate at a convergent plate boundary. Most of the material in the accretionary wedge consists of marine sediments scraped off from the d ...

es developed west of it, meaning Chaitenia constituted a backstop. Chaitenia is not thought to extend beyond the Huincul lineament to the north, beyond which lies the Chilenia terrane.

References

category:Geology of Aysén Region Geology of Chubut Province category:Geology of Los Lagos Region category:Geology of Los Ríos Region Geology of Neuquén Province Geology of the Andes Island arcs category:Terranes {{palaeo-geo-stub