The Precordillera Terrane or Cuyania was an ancient microcontinent or terrane

Terrane

A terrane in geology is short-hand term for a tectonostratigraphic terrane, which is a fragment of crustal material formed on, or broken off from, one tectonic plate and accreted or "sutured" to crust lying on another plate...

 whose history affected many of the older rocks of Cuyo

Cuyo (Argentina)

Cuyo is the name given to the wine-producing, mountainous area of central-west Argentina. Historically it comprised the provinces of San Juan, San Luis and Mendoza. The term New Cuyo is a modern one, which indicates both Cuyo proper and the province of La Rioja...

 in Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. It was separated by oceanic crust

Oceanic crust

Oceanic crust is the part of Earth's lithosphere that surfaces in the ocean basins. Oceanic crust is primarily composed of mafic rocks, or sima, which is rich in iron and magnesium...

 from the Chilenia

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 Cuyania was already amalgamated with Gondwana.-Sources:*...

 terrane which accreted into it at ~420-390 Ma when Cuyania was already amalgamated with Gondwana

Gondwana

In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...

. The hypothesized Mejillonia Terrane in the coast of northern Chile

Norte Grande, Chile

The Norte Grande is one of the five natural regions into which CORFO divided continental Chile in 1950. It borders Peru to the north, the Pacific Ocean to the west, the Altiplano, Bolivia and Argentina to the east, and the Copiapó River to the south, beyond which lies the Norte Chico natural...

 is considered by some geologist

Geologist

A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes and history that has shaped it. Geologists usually engage in studying geology. Geologists, studying more of an applied science than a theoretical one, must approach Geology using...

s to be a single block with Cuyania.

Sources

• The Andes - Tectonic Evolution