Chaitenia is a distinct fragment of Earth's crust in southern Chile. Rocks of Chaitenia represents an ancient island arc that existed next to Patagonia 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, wher ...

(''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 Chilenia was an ancient microcontinent or terrane whose history affected many of the older rocks of central Chile and western Argentina. It was once separated by oceanic crust from the Cuyania terrane to which it accreted at ~420-390 Ma when Cuya ...

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