Famatinian orogeny

[1] The orogeny involved metamorphism and deformation in the crust and the eruption and intrusion of magma along a Famatinian magmatic arc that formed a chain of volcanoes.

[7] To the south in La Pampa Province, outcrops associated with the orogeny are scarce since most of that region has become blanketed by much more recent Quaternary sediments.

[note 2] This has been explained by adding that the continent Laurentia could have collided with Gondwana (at what is today western South America) in early Paleozoic times due to the closure of the Iapetus Ocean.

[13] Supporting this hypothesis is the suggestion that the orogens have "truncated ends" that can be matched and that both share the commonality of having carbonate platform sediments at what is today their western side.

Further a third model claims Cuyania is para-autochthonous and arrived at its current place by strike-slip fault movements starting not from Laurentia but from another region of Gondwana.

[12] The fact that Precordillera terrane has many trilobite genera in common with Laurentia but many species are endemic have led to some differing interpretations on what paleogeographic and tectonic history conditions are plausible explanations for this biogeography.

Paleogeographic reconstruction of Gondwana and Laurentia about 70 million years before the Famatinian orogeny. The Famatinian orogeny took place near the right border of the area marked as " Río Plata ". Terranes and microcontinents such as Cuyania , Pampia and Chilenia are omitted.