Laurentia-Gondwana collision: the origin of the Famatinian-Appalachian Orogenic Belt (a review)

Publisher Website
Google Scholar
Abstract
Evidence from Cambrian to Devonian palaeogeography, the Laurentian provenance of Precordillera, and comparison of Lower Palaeozoic tectonic, metamorphic, and magmatic events, suggests a common collisional origin for the Taconian Appalachians and the Famatinian (Puna, Sierras Pampeanas, North Patagonian Massif) orogenic belt. Detached from Eastern Laurentia following collision, the Occidentalia terrane (west of the Famatinian orogenic belt) is partly covered by the Precordillera carbonate bank, which contains syn-collisional 460 Ma K-bentonites, related to the Puna and Famatinian arcs. In both the Appalachian and the Famatinian belts, a mostly Cambrian pre-collisional subduction regime developed at the western margin of Gondwana, following the opening of Iapetus. Laurentia-Gondwana collision produced deep thrusting and crustal melting. As in the Blue Ridge of the Appalachian Mountains, oceanic and mantle rocks, and slices of Grenvillian basement were emplaced along the western side of the Famatinian belt. This hypothesis gives continuity to a paired Taconian-Famatinian tectonic setting: a western Lower Palaeozoic platform overlying Grenvillian basement, and an eastern complex of a Lower-Middle Palaeozoic igneous-metamorphic belt with Proterozoic inliers.