Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

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Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility. / Maffione, Marco; Hernandez-Moreno, Catalina; Ghiglione, Matias C.; Speranza, Fabio; van Hinsbergen, Douwe J J; Lodolo, Emanuele.

In: Tectonophysics, Vol. 665, 08.12.2015, p. 236-250.

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APA

Maffione, M., Hernandez-Moreno, C., Ghiglione, M. C., Speranza, F., van Hinsbergen, D. J. J., & Lodolo, E. (2015). Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility. Tectonophysics, 665, 236-250. https://doi.org/10.1016/j.tecto.2015.10.008

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Author

Maffione, Marco ; Hernandez-Moreno, Catalina ; Ghiglione, Matias C. ; Speranza, Fabio ; van Hinsbergen, Douwe J J ; Lodolo, Emanuele. / Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility. In: Tectonophysics. 2015 ; Vol. 665. pp. 236-250.

Bibtex

@article{199993095f324db5b3117b3757d8029a,
title = "Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility",
abstract = "The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known as the Patagonian Orocline (here renamed as Patagonian Arc), and the exhumation mechanism of an upper amphibolite facies metamorphic complex currently exposed in Cordillera Darwin. Here, we present results of anisotropy of magnetic susceptibility (AMS) from 22 sites in Upper Cretaceous to upper Eocene sedimentary rocks within the internal structural domain of the Magallanes fold-and-thrust belt in Tierra del Fuego (Argentina). AMS parameters from most sites reveal a weak tectonic overprint of the original magnetic fabric, which was likely acquired upon layer-parallel shortening soon after sedimentation. Magnetic lineation from 17 sites is interpreted to have formed during compressive tectonic phases associated to a continuous. ~. N-S contraction. Our data, combined with the existing AMS database from adjacent areas, show that the Early Cretaceous-late Oligocene tectonic phases in the Southern Andes yielded continuous contraction, variable from. ~. E-W in the Patagonian Andes to. ~. N-S in the Fuegian Andes, which defined a radial strain field. A direct implication is that the exhumation of the Cordillera Darwin metamorphic complex occurred under compressive, rather than extensional or strike-slip tectonics, as alternatively proposed. If we agree with recent works considering the curved Magallanes fold-and-thrust belt as a primary arc (i.e., no relative vertical-axis rotation of the limbs occurs during its formation), then other mechanisms different from oroclinal bending should be invoked to explain the documented radial strain field. We tentatively propose a kinematic model in which reactivation of variably oriented Jurassic faults at the South American continental margin controlled the Late Cretaceous to Cenozoic evolution of the Magallanes fold-and-thrust belt, yielding the observed deformation pattern.",
keywords = "Anisotropy of magnetic susceptibility, Cordillera Darwin, Patagonian Orocline, Southern Andes, Tectonics",
author = "Marco Maffione and Catalina Hernandez-Moreno and Ghiglione, {Matias C.} and Fabio Speranza and {van Hinsbergen}, {Douwe J J} and Emanuele Lodolo",
year = "2015",
month = dec,
day = "8",
doi = "10.1016/j.tecto.2015.10.008",
language = "English",
volume = "665",
pages = "236--250",
journal = "Tectonophysics",
issn = "0040-1951",
publisher = "Elsevier",

}

RIS

TY - JOUR

T1 - Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

AU - Maffione, Marco

AU - Hernandez-Moreno, Catalina

AU - Ghiglione, Matias C.

AU - Speranza, Fabio

AU - van Hinsbergen, Douwe J J

AU - Lodolo, Emanuele

PY - 2015/12/8

Y1 - 2015/12/8

N2 - The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known as the Patagonian Orocline (here renamed as Patagonian Arc), and the exhumation mechanism of an upper amphibolite facies metamorphic complex currently exposed in Cordillera Darwin. Here, we present results of anisotropy of magnetic susceptibility (AMS) from 22 sites in Upper Cretaceous to upper Eocene sedimentary rocks within the internal structural domain of the Magallanes fold-and-thrust belt in Tierra del Fuego (Argentina). AMS parameters from most sites reveal a weak tectonic overprint of the original magnetic fabric, which was likely acquired upon layer-parallel shortening soon after sedimentation. Magnetic lineation from 17 sites is interpreted to have formed during compressive tectonic phases associated to a continuous. ~. N-S contraction. Our data, combined with the existing AMS database from adjacent areas, show that the Early Cretaceous-late Oligocene tectonic phases in the Southern Andes yielded continuous contraction, variable from. ~. E-W in the Patagonian Andes to. ~. N-S in the Fuegian Andes, which defined a radial strain field. A direct implication is that the exhumation of the Cordillera Darwin metamorphic complex occurred under compressive, rather than extensional or strike-slip tectonics, as alternatively proposed. If we agree with recent works considering the curved Magallanes fold-and-thrust belt as a primary arc (i.e., no relative vertical-axis rotation of the limbs occurs during its formation), then other mechanisms different from oroclinal bending should be invoked to explain the documented radial strain field. We tentatively propose a kinematic model in which reactivation of variably oriented Jurassic faults at the South American continental margin controlled the Late Cretaceous to Cenozoic evolution of the Magallanes fold-and-thrust belt, yielding the observed deformation pattern.

AB - The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known as the Patagonian Orocline (here renamed as Patagonian Arc), and the exhumation mechanism of an upper amphibolite facies metamorphic complex currently exposed in Cordillera Darwin. Here, we present results of anisotropy of magnetic susceptibility (AMS) from 22 sites in Upper Cretaceous to upper Eocene sedimentary rocks within the internal structural domain of the Magallanes fold-and-thrust belt in Tierra del Fuego (Argentina). AMS parameters from most sites reveal a weak tectonic overprint of the original magnetic fabric, which was likely acquired upon layer-parallel shortening soon after sedimentation. Magnetic lineation from 17 sites is interpreted to have formed during compressive tectonic phases associated to a continuous. ~. N-S contraction. Our data, combined with the existing AMS database from adjacent areas, show that the Early Cretaceous-late Oligocene tectonic phases in the Southern Andes yielded continuous contraction, variable from. ~. E-W in the Patagonian Andes to. ~. N-S in the Fuegian Andes, which defined a radial strain field. A direct implication is that the exhumation of the Cordillera Darwin metamorphic complex occurred under compressive, rather than extensional or strike-slip tectonics, as alternatively proposed. If we agree with recent works considering the curved Magallanes fold-and-thrust belt as a primary arc (i.e., no relative vertical-axis rotation of the limbs occurs during its formation), then other mechanisms different from oroclinal bending should be invoked to explain the documented radial strain field. We tentatively propose a kinematic model in which reactivation of variably oriented Jurassic faults at the South American continental margin controlled the Late Cretaceous to Cenozoic evolution of the Magallanes fold-and-thrust belt, yielding the observed deformation pattern.

KW - Anisotropy of magnetic susceptibility

KW - Cordillera Darwin

KW - Patagonian Orocline

KW - Southern Andes

KW - Tectonics

UR - http://www.scopus.com/inward/record.url?scp=84957725001&partnerID=8YFLogxK

U2 - 10.1016/j.tecto.2015.10.008

DO - 10.1016/j.tecto.2015.10.008

M3 - Article

AN - SCOPUS:84957725001

VL - 665

SP - 236

EP - 250

JO - Tectonophysics

JF - Tectonophysics

SN - 0040-1951

ER -