Evolución del campo de esfuerzos en Tierra del Fuego durante el Mesozoico-Cenozoico (extremo meridional de la Cordillera Andina)
- A. Maestro 1
- P. Ruano 2
- P.J. Torres Carbonell 3
- F. Bohoyo 1
- J. Galindo-Zaldívar 2
- A. Pedrera 1
- A. Ruíz-Constán 1
- L. González-Castillo 2
- P. Ibarra 1
- J. López-Martínez 4
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1
Instituto Geológico y Minero de España
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2
Universidad de Granada
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- 3 Centro Austral de Investigaciones Científicas (CADIC-CONICET)
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4
Universidad Autónoma de Madrid
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ISSN: 1576-5172
Année de publication: 2016
Titre de la publication: IX CONGRESO GEOLÓGICO DE ESPAÑA
Número: 16
Pages: 443-446
Type: Article
D'autres publications dans: Geotemas (Madrid)
Résumé
Tierra del Fuego comprises the southernmost part of the Andean Cordillera known as Fuegian Andes, and presents a complex tectonic history since the Mesozoic. To contribute to the knowledge of the tectonic evolution of the Fuegian Andes region, 1496 brittle mesostructures were measured at 86 sites located in Late Jurassic to Quaternary rocks. A total of 125 palaeostress tensors were obtained. Fault data were analyzed using the Right Dihedra, y-R diagram, Etchecopar's and Search Grid Inversion Palaeostress determination methods. The orientations of joints, gashes and clastic dikes have also been used to establish maximum and minimum horizontal stress trends. The σ1orientation shows a dominant NE-SW direction and ENE -WSW to E-W, NW-SE and N-S secondary σ1 stress directions are observed. The σ3 orientation shows two main modes trending ENE-WSW and NW-SE, and three secondary σ3 stress directions (NE-SW, E-W and NNW-SSE). The o btained stress evolution is consistent with a regional NE-SW compressive stress field active in the area since the late Cretaceous. During the late Cretaceous, a regional counterclockwise rotation of 30º started, which gave rise to the Patagonia orocline. The final curvature of the chain may have been acquired due to the interaction of the orogenic wedge with the Rio Chico promontory during the late Cretaceous-early Miocene. The promontory indentation caused a variation in the trend of the compressive stress axis, showing NE-SW direction in the western part and N-S to NW-SE in the eastern sector. Finally, since the late Miocene, the strike-slip movement of the Magallanes-Fagnano Fault System deflects the NE-SW stress trajectories changing to an E-W direction.