Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile

A paleomagnetic and AMS study on Eocene plutonic complexes in the Calama area, northern Chile, reveals high-temperature, high-coercivity magnetizations of dominantly thermoremanent origin and magnetic fabrics controlled by magnetite. The paleomagnetic results indicate that ~. 43. Ma plutons underwen...

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Autores principales: Somoza, R., Tomlinson, A.J., Zaffarana, C.B., Singer, S.E., Puigdomenech Negre, C.G., Raposo, M.I.B., Dilles, J.H.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00401951_v654_n_p113_Somoza
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spelling todo:paper_00401951_v654_n_p113_Somoza2023-10-03T14:50:21Z Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile Somoza, R. Tomlinson, A.J. Zaffarana, C.B. Singer, S.E. Puigdomenech Negre, C.G. Raposo, M.I.B. Dilles, J.H. Central Andes Chuquicamata Magnetic fabric Tectonic rotations Coercive force Deformation Geomagnetism Magnetic polarity Magnetism Metals Rotation Central Andes Chuquicamata Internal structure Low temperatures Magnetic fabrics Regional tectonics Solid state deformation Tectonic rotations Tectonics deformation emplacement Eocene foliation high temperature magnetic fabric paleomagnetism pluton tectonic rotation thermoremanent magnetization Andes Antofagasta Calama Chile A paleomagnetic and AMS study on Eocene plutonic complexes in the Calama area, northern Chile, reveals high-temperature, high-coercivity magnetizations of dominantly thermoremanent origin and magnetic fabrics controlled by magnetite. The paleomagnetic results indicate that ~. 43. Ma plutons underwent clockwise tectonic rotation, whereas adjacent ~. 39. Ma plutons did not undergo discernible rotation. This points to a middle Eocene age for the younger tectonic rotations associated with the Central Andean Rotation Pattern in the Chuquicamata-Calama area.The petrofabric in these rocks formed under conditions ranging from purely magmatic (i.e. before full crystallization) to low-temperature solid-state deformation. AMS and paleomagnetism suggest that the plutonic bodies were formed by progressive amalgamation of subvertical magma sheets spanning multiple magnetic polarity chrons. The parallelism between magmatic and tectonic foliations suggests that regional tectonic stress controlled ascent, emplacement and rock deformation during cooling. In this context, we suggest that magma ascent and emplacement in the upper crust likely exploited Mesozoic structures which were locally reactivated in the Eocene. © 2015 Elsevier B.V. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00401951_v654_n_p113_Somoza
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Central Andes
Chuquicamata
Magnetic fabric
Tectonic rotations
Coercive force
Deformation
Geomagnetism
Magnetic polarity
Magnetism
Metals
Rotation
Central Andes
Chuquicamata
Internal structure
Low temperatures
Magnetic fabrics
Regional tectonics
Solid state deformation
Tectonic rotations
Tectonics
deformation
emplacement
Eocene
foliation
high temperature
magnetic fabric
paleomagnetism
pluton
tectonic rotation
thermoremanent magnetization
Andes
Antofagasta
Calama
Chile
spellingShingle Central Andes
Chuquicamata
Magnetic fabric
Tectonic rotations
Coercive force
Deformation
Geomagnetism
Magnetic polarity
Magnetism
Metals
Rotation
Central Andes
Chuquicamata
Internal structure
Low temperatures
Magnetic fabrics
Regional tectonics
Solid state deformation
Tectonic rotations
Tectonics
deformation
emplacement
Eocene
foliation
high temperature
magnetic fabric
paleomagnetism
pluton
tectonic rotation
thermoremanent magnetization
Andes
Antofagasta
Calama
Chile
Somoza, R.
Tomlinson, A.J.
Zaffarana, C.B.
Singer, S.E.
Puigdomenech Negre, C.G.
Raposo, M.I.B.
Dilles, J.H.
Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile
topic_facet Central Andes
Chuquicamata
Magnetic fabric
Tectonic rotations
Coercive force
Deformation
Geomagnetism
Magnetic polarity
Magnetism
Metals
Rotation
Central Andes
Chuquicamata
Internal structure
Low temperatures
Magnetic fabrics
Regional tectonics
Solid state deformation
Tectonic rotations
Tectonics
deformation
emplacement
Eocene
foliation
high temperature
magnetic fabric
paleomagnetism
pluton
tectonic rotation
thermoremanent magnetization
Andes
Antofagasta
Calama
Chile
description A paleomagnetic and AMS study on Eocene plutonic complexes in the Calama area, northern Chile, reveals high-temperature, high-coercivity magnetizations of dominantly thermoremanent origin and magnetic fabrics controlled by magnetite. The paleomagnetic results indicate that ~. 43. Ma plutons underwent clockwise tectonic rotation, whereas adjacent ~. 39. Ma plutons did not undergo discernible rotation. This points to a middle Eocene age for the younger tectonic rotations associated with the Central Andean Rotation Pattern in the Chuquicamata-Calama area.The petrofabric in these rocks formed under conditions ranging from purely magmatic (i.e. before full crystallization) to low-temperature solid-state deformation. AMS and paleomagnetism suggest that the plutonic bodies were formed by progressive amalgamation of subvertical magma sheets spanning multiple magnetic polarity chrons. The parallelism between magmatic and tectonic foliations suggests that regional tectonic stress controlled ascent, emplacement and rock deformation during cooling. In this context, we suggest that magma ascent and emplacement in the upper crust likely exploited Mesozoic structures which were locally reactivated in the Eocene. © 2015 Elsevier B.V.
format JOUR
author Somoza, R.
Tomlinson, A.J.
Zaffarana, C.B.
Singer, S.E.
Puigdomenech Negre, C.G.
Raposo, M.I.B.
Dilles, J.H.
author_facet Somoza, R.
Tomlinson, A.J.
Zaffarana, C.B.
Singer, S.E.
Puigdomenech Negre, C.G.
Raposo, M.I.B.
Dilles, J.H.
author_sort Somoza, R.
title Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile
title_short Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile
title_full Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile
title_fullStr Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile
title_full_unstemmed Tectonic rotations and internal structure of Eocene plutons in Chuquicamata, northern Chile
title_sort tectonic rotations and internal structure of eocene plutons in chuquicamata, northern chile
url http://hdl.handle.net/20.500.12110/paper_00401951_v654_n_p113_Somoza
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