Evolución geodinámica durante el Paleozoico Superior de la Cordillera Frontal y Precordillera Occidental entre los 30º y 33º S (Andes Argentinos)
- N. Heredia 1
- P. Farias 2
- J. García Sansegundo 2
- L. Giambiagi 3
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1
Instituto Geológico y Minero de España
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2
Universidad de Oviedo
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3
Consejo Nacional de Investigaciones Científicas y Técnicas
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Consejo Nacional de Investigaciones Científicas y Técnicas
Buenos Aires, Argentina
ISSN: 1576-5172
Year of publication: 2012
Issue Title: VIII Congreso Geológico de España, Oviedo, 17-19 de julio, 2012.
Issue: 13
Pages: 1883-1886
Type: Article
More publications in: Geotemas (Madrid)
Abstract
The Paleozoic basement of the Argentine Andes between 30 and 33º S consists of two sets of rocks showing different stratigraphy, structure and metamorphism. The lower one is represented by preUpper Carboniferous rocks, folded under low-grade metamorphic conditions. These folds show a westvergence in the Frontal Cordillera, and east-vergence in the Precordillera. A preorogenic succession, Late Proterozoic-Late Devonian in age, can be distinguish in this basal set, deposited in two different continental margins: a fore-arc basin, located over the active margin of Chilenia (Frontal Cordillera) and another basin in the passive margin of Gondwana (Precordillera). The existence of an Early Carboniferous synorogenic sequence, deposited in a peripheral foreland basin, point out to the collision of these continents after Late Devonian times (Chanic Orogeny of the Famatinian Cycle). The upper set consists of Late Carboniferous-Permian rocks, affected by east directed thrusts under non-metamorphic conditions. This deformation can be related to the SanRafaelic Orogeny (Gondwanan Cycle). Two different successions, located over an active margin of Gondwana, can be distinguish in this upper set of the Paleozoic basement: a preorogenic one, deposited in a back-arc basin, and a synorogenic one (Late Carboniferous-Permian in age), deposited in a retroarc foreland basin.