La Serie Oriental del río Maule (Constitución, Chile)Estructura y metamorfismo
- J. García-Sansegundo 1
- A. Rubio-Ordóñez 1
- N. Heredia 2
- J. Santos-Martínez 1
- C. Palape 3
- A. Cuesta 1
- P. Farias 1
- G. Gallastegui 2
- O. García-Moreno 1
- F. Martín-González 4
- T. Hyppolito 5
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1
Universidad de Oviedo
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2
Instituto Geológico y Minero de España
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3
Universidad de Chile
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4
Universidad Rey Juan Carlos
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- 5 Universidade de São Paulo (Brasil)
ISSN: 1576-5172
Année de publication: 2021
Titre de la publication: X Congreso Geológico de España
Número: 18
Pages: 1069
Type: Article
D'autres publications dans: Geotemas (Madrid)
Résumé
During the Upper Carboniferous - Lower Permian, the basement of the Cordillera de la Costa was deformed by the Gondwanan Orogeny, developed by the subduction of the Paleo-Pacific plate under Gondwana. In the Maule sector (35ºS), the following rocks are distinguished: (i) the Western Series (metapelites from an exhumed accretion prism) and the Eastern Series (metasedi- ments of a forearc basin). Three episodes of Gondwanic deformation that affect both series have been distinguished: - D1: In the Western Series it consists of a foliation (S1) developed under HP-LT conditions, while in the Oriental it com- prises east-verging folds, with the S1 associated and developed in low grade metamorphic conditions. - D2 (main episode): It is characterized by thrusts and east-verging folds, with the associated regional foliation (S2). D2 structures are progressively better developed towards the West. - D3: N-S open folds. The metamorphic jump between both series during D1 and the increase in the strain gradient D2 towards the West, has been interpreted as due to the overthrusting of the Western Series over the Eastern Series during D2, which caused a subduction interruption, possibly because of the arrival in the trench of an underwater relief.