Estructura del basamento Paleozoico en la costa de Chile a latitud 31º 30’S (Huentelauquén, Chile)
- J. García-Sansegundo 1
- P. Farias 1
- A. Rubio-Ordóñez 1
- G. Gallastegui 2
- N. Heredia 2
- A. Cuesta 1
- R. Charrier 3
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1
Universidad de Oviedo
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- 2 Instituto Geológico y Minero de España (IGME)
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3
Universidad de Chile
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ISSN: 1576-5172
Année de publication: 2012
Titre de la publication: VIII Congreso Geológico de España, Oviedo, 17-19 de julio, 2012.
Número: 13
Pages: 1871-1874
Type: Article
D'autres publications dans: Geotemas (Madrid)
Résumé
Palaeozoic rocks of the Choapa Metamorphic Complex (ChMC) (metabasites, gneisses and quartz-schists) and sedimentary and meta-sedimentary rocks of the Arrayán and Huentelauquén formations crop out to the North of Los Vilos. Near Huentelauquén, the ChMC has been affected by three deformation episodes related to the Gondwanan Orogenic Cycle. The first episode (D1) is represented by a foliation (S1) formed under HP-LT metamorphic conditions and preserved in syn-D2 garnet and albite porphyroblasts. A generalized crenulation cleavage (S2) was developed during the second deformation episode (D2) characterised by decompression. This episode is responsible for the exhumation of the ChMC, accommodated by east-directed thrusts overlying the ChMC on the Arrayán Fm., producing more than 20 km shortening. The third deformation episode (D3) is represented by a west-verging kilometricscale anticline, with a thrust in its reverse limb. Minor folds and crenulations are also associated to D3. D3 structures affect the ChMC and the Arrayán Fm, being responsible of the inversion of the D2 thrusts. The Late-Carboniferous-Permian Huentelauquén Fm is the youngest one deformed by Gondwanan structures.