New and revised paleomagnetic data from the southern central Andes: Testing tectonic rotations

Florencia N. Milanese; Augusto E. Rapalini; Lucía Sagripanti; Silvana Geuna; Mark J. Dekkers; Rodrigo Feo; Pablo Franceschinis; Donaldo Bran; Andrés Folguera

doi:10.1016/j.jsames.2023.104220

New and revised paleomagnetic data from the southern central Andes: Testing tectonic rotations

Florencia N. Milanese^*, Augusto E. Rapalini, Lucía Sagripanti, Silvana Geuna, Mark J. Dekkers, Rodrigo Feo, Pablo Franceschinis, Donaldo Bran, Andrés Folguera

^*Corresponding author for this work

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

A paleomagnetic study performed in Plio-Pleistocene volcanic rocks of two localities in the Southern Central Andes is presented. The region corresponds to the transition zone between the Central and the Patagonian Andes. In the latter, deformation is almost exclusively controlled by the dextral-strike slip Liquiñe-Ofqui Fault Zone, that extends from ∼47 °S to ∼38 °S and accommodates the deformation generated by the oblique subduction of the Nazca Plate below South America. To the north of ∼36 °S, deformation is mainly contractional. Our study was carried out in the transition zone between both tectonic regimes. Sampling consisted of 31 paleomagnetic sites distributed in two localities: the Loncopué (∼38.0 °S, 70.7 °W) and Andacollo (∼37.2 °S, 70.8 °W) areas. We sampled Pliocene and Pleistocene volcanic rocks with ages younger than 5 Ma. After stepwise demagnetization and principal component analysis, site mean remanence directions were computed. Both localities show non-significant clockwise rotations of 1.7° ± 14.4° (Loncopué) and 8.1° ± 8.4° (Andacollo). Although the presently available database does not support significant tectonic rotation of the Andacollo lavas, preliminary results obtained from upper Miocene volcanics in a nearby area indicating ∼20° of clockwise rotation, encourage further studies to improve the resolution of the paleomagnetic data to determine if crustal block rotations have been, or still are, part of the Andean deformational processes. A revision of previously published paleomagnetic data in the northern Patagonian Andes suggests that, against original claims, no significant tectonic rotations associated to the Liquiñe-Ofqui Fault Zone, between ∼39 and 37.5 °S, can be unambiguously demonstrated.

Original language	English
Article number	104220
Pages (from-to)	1-17
Number of pages	17
Journal	Journal of South American Earth Sciences
Volume	124
DOIs	https://doi.org/10.1016/j.jsames.2023.104220
Publication status	Published - Apr 2023

Bibliographical note

Funding Information:
This study was supported by University of Buenos Aires through grant UBACyT 22320200100593BA to A.E.R. Further economic support was provided by Agencia Nacional de Promoción Científica y Técnica (ANPCyT) of Argentina with grant PICT 2018-00130 to A.E.R. CONICET (Argentina) supported F.N.M. with a post-doctoral fellowship during these studies. The authors acknowledge the Mapuche community Millain Currical of Caviahue for their friendly reception and permission for sampling. This work benefited of EPOS TCS MSL TNA access of F.M. to the paleomagnetic laboratory “Fort Hoofddijk”, supported by the European Community HORIZON 2020 research and innovation program under grant agreement N 676564 , and national funding from the Dutch Research Council (NWO). Comments from José Cembrano, an anonymous reviewer and Editor in Chief helped to improve the science behind this manuscript.

Funding Information:
This study was supported by University of Buenos Aires through grant UBACyT 22320200100593BA to A.E.R. Further economic support was provided by Agencia Nacional de Promoción Científica y Técnica (ANPCyT) of Argentina with grant PICT 2018-00130 to A.E.R. CONICET (Argentina) supported F.N.M. with a post-doctoral fellowship during these studies. The authors acknowledge the Mapuche community Millain Currical of Caviahue for their friendly reception and permission for sampling. This work benefited of EPOS TCS MSL TNA access of F.M. to the paleomagnetic laboratory “Fort Hoofddijk”, supported by the European Community HORIZON 2020 research and innovation program under grant agreement N 676564, and national funding from the Dutch Research Council (NWO). Comments from José Cembrano, an anonymous reviewer and Editor in Chief helped to improve the science behind this manuscript.

Publisher Copyright:
© 2023 Elsevier Ltd

Funding

This study was supported by University of Buenos Aires through grant UBACyT 22320200100593BA to A.E.R. Further economic support was provided by Agencia Nacional de Promoción Científica y Técnica (ANPCyT) of Argentina with grant PICT 2018-00130 to A.E.R. CONICET (Argentina) supported F.N.M. with a post-doctoral fellowship during these studies. The authors acknowledge the Mapuche community Millain Currical of Caviahue for their friendly reception and permission for sampling. This work benefited of EPOS TCS MSL TNA access of F.M. to the paleomagnetic laboratory “Fort Hoofddijk”, supported by the European Community HORIZON 2020 research and innovation program under grant agreement N 676564 , and national funding from the Dutch Research Council (NWO). Comments from José Cembrano, an anonymous reviewer and Editor in Chief helped to improve the science behind this manuscript. This study was supported by University of Buenos Aires through grant UBACyT 22320200100593BA to A.E.R. Further economic support was provided by Agencia Nacional de Promoción Científica y Técnica (ANPCyT) of Argentina with grant PICT 2018-00130 to A.E.R. CONICET (Argentina) supported F.N.M. with a post-doctoral fellowship during these studies. The authors acknowledge the Mapuche community Millain Currical of Caviahue for their friendly reception and permission for sampling. This work benefited of EPOS TCS MSL TNA access of F.M. to the paleomagnetic laboratory “Fort Hoofddijk”, supported by the European Community HORIZON 2020 research and innovation program under grant agreement N 676564, and national funding from the Dutch Research Council (NWO). Comments from José Cembrano, an anonymous reviewer and Editor in Chief helped to improve the science behind this manuscript.

Keywords

Cola de Zorro formation
Guañacos formation
Liquiñe-Ofqui
Neogene
Neuquén Andes
Volcanics

Access to Document

10.1016/j.jsames.2023.104220

1-s2.0-S0895981123000317-mainFinal published version, 28.4 MBLicence: Taverne

Cite this

@article{b7137674bb514f1fb3d9db7c51477f3a,

title = "New and revised paleomagnetic data from the southern central Andes: Testing tectonic rotations",

abstract = "A paleomagnetic study performed in Plio-Pleistocene volcanic rocks of two localities in the Southern Central Andes is presented. The region corresponds to the transition zone between the Central and the Patagonian Andes. In the latter, deformation is almost exclusively controlled by the dextral-strike slip Liqui{\~n}e-Ofqui Fault Zone, that extends from ∼47 °S to ∼38 °S and accommodates the deformation generated by the oblique subduction of the Nazca Plate below South America. To the north of ∼36 °S, deformation is mainly contractional. Our study was carried out in the transition zone between both tectonic regimes. Sampling consisted of 31 paleomagnetic sites distributed in two localities: the Loncopu{\'e} (∼38.0 °S, 70.7 °W) and Andacollo (∼37.2 °S, 70.8 °W) areas. We sampled Pliocene and Pleistocene volcanic rocks with ages younger than 5 Ma. After stepwise demagnetization and principal component analysis, site mean remanence directions were computed. Both localities show non-significant clockwise rotations of 1.7° ± 14.4° (Loncopu{\'e}) and 8.1° ± 8.4° (Andacollo). Although the presently available database does not support significant tectonic rotation of the Andacollo lavas, preliminary results obtained from upper Miocene volcanics in a nearby area indicating ∼20° of clockwise rotation, encourage further studies to improve the resolution of the paleomagnetic data to determine if crustal block rotations have been, or still are, part of the Andean deformational processes. A revision of previously published paleomagnetic data in the northern Patagonian Andes suggests that, against original claims, no significant tectonic rotations associated to the Liqui{\~n}e-Ofqui Fault Zone, between ∼39 and 37.5 °S, can be unambiguously demonstrated.",

keywords = "Cola de Zorro formation, Gua{\~n}acos formation, Liqui{\~n}e-Ofqui, Neogene, Neuqu{\'e}n Andes, Volcanics",

author = "Milanese, {Florencia N.} and Rapalini, {Augusto E.} and Luc{\'i}a Sagripanti and Silvana Geuna and Dekkers, {Mark J.} and Rodrigo Feo and Pablo Franceschinis and Donaldo Bran and Andr{\'e}s Folguera",

note = "Funding Information: This study was supported by University of Buenos Aires through grant UBACyT 22320200100593BA to A.E.R. Further economic support was provided by Agencia Nacional de Promoci{\'o}n Cient{\'i}fica y T{\'e}cnica (ANPCyT) of Argentina with grant PICT 2018-00130 to A.E.R. CONICET (Argentina) supported F.N.M. with a post-doctoral fellowship during these studies. The authors acknowledge the Mapuche community Millain Currical of Caviahue for their friendly reception and permission for sampling. This work benefited of EPOS TCS MSL TNA access of F.M. to the paleomagnetic laboratory “Fort Hoofddijk”, supported by the European Community HORIZON 2020 research and innovation program under grant agreement N 676564 , and national funding from the Dutch Research Council (NWO). Comments from Jos{\'e} Cembrano, an anonymous reviewer and Editor in Chief helped to improve the science behind this manuscript. Funding Information: This study was supported by University of Buenos Aires through grant UBACyT 22320200100593BA to A.E.R. Further economic support was provided by Agencia Nacional de Promoci{\'o}n Cient{\'i}fica y T{\'e}cnica (ANPCyT) of Argentina with grant PICT 2018-00130 to A.E.R. CONICET (Argentina) supported F.N.M. with a post-doctoral fellowship during these studies. The authors acknowledge the Mapuche community Millain Currical of Caviahue for their friendly reception and permission for sampling. This work benefited of EPOS TCS MSL TNA access of F.M. to the paleomagnetic laboratory “Fort Hoofddijk”, supported by the European Community HORIZON 2020 research and innovation program under grant agreement N 676564, and national funding from the Dutch Research Council (NWO). Comments from Jos{\'e} Cembrano, an anonymous reviewer and Editor in Chief helped to improve the science behind this manuscript. Publisher Copyright: {\textcopyright} 2023 Elsevier Ltd",

year = "2023",

month = apr,

doi = "10.1016/j.jsames.2023.104220",

language = "English",

volume = "124",

pages = "1--17",

journal = "Journal of South American Earth Sciences",

issn = "0895-9811",

publisher = "Elsevier BV",

}

TY - JOUR

T1 - New and revised paleomagnetic data from the southern central Andes

T2 - Testing tectonic rotations

AU - Milanese, Florencia N.

AU - Rapalini, Augusto E.

AU - Sagripanti, Lucía

AU - Geuna, Silvana

AU - Dekkers, Mark J.

AU - Feo, Rodrigo

AU - Franceschinis, Pablo

AU - Bran, Donaldo

AU - Folguera, Andrés

N1 - Funding Information: This study was supported by University of Buenos Aires through grant UBACyT 22320200100593BA to A.E.R. Further economic support was provided by Agencia Nacional de Promoción Científica y Técnica (ANPCyT) of Argentina with grant PICT 2018-00130 to A.E.R. CONICET (Argentina) supported F.N.M. with a post-doctoral fellowship during these studies. The authors acknowledge the Mapuche community Millain Currical of Caviahue for their friendly reception and permission for sampling. This work benefited of EPOS TCS MSL TNA access of F.M. to the paleomagnetic laboratory “Fort Hoofddijk”, supported by the European Community HORIZON 2020 research and innovation program under grant agreement N 676564 , and national funding from the Dutch Research Council (NWO). Comments from José Cembrano, an anonymous reviewer and Editor in Chief helped to improve the science behind this manuscript. Funding Information: This study was supported by University of Buenos Aires through grant UBACyT 22320200100593BA to A.E.R. Further economic support was provided by Agencia Nacional de Promoción Científica y Técnica (ANPCyT) of Argentina with grant PICT 2018-00130 to A.E.R. CONICET (Argentina) supported F.N.M. with a post-doctoral fellowship during these studies. The authors acknowledge the Mapuche community Millain Currical of Caviahue for their friendly reception and permission for sampling. This work benefited of EPOS TCS MSL TNA access of F.M. to the paleomagnetic laboratory “Fort Hoofddijk”, supported by the European Community HORIZON 2020 research and innovation program under grant agreement N 676564, and national funding from the Dutch Research Council (NWO). Comments from José Cembrano, an anonymous reviewer and Editor in Chief helped to improve the science behind this manuscript. Publisher Copyright: © 2023 Elsevier Ltd

PY - 2023/4

Y1 - 2023/4

N2 - A paleomagnetic study performed in Plio-Pleistocene volcanic rocks of two localities in the Southern Central Andes is presented. The region corresponds to the transition zone between the Central and the Patagonian Andes. In the latter, deformation is almost exclusively controlled by the dextral-strike slip Liquiñe-Ofqui Fault Zone, that extends from ∼47 °S to ∼38 °S and accommodates the deformation generated by the oblique subduction of the Nazca Plate below South America. To the north of ∼36 °S, deformation is mainly contractional. Our study was carried out in the transition zone between both tectonic regimes. Sampling consisted of 31 paleomagnetic sites distributed in two localities: the Loncopué (∼38.0 °S, 70.7 °W) and Andacollo (∼37.2 °S, 70.8 °W) areas. We sampled Pliocene and Pleistocene volcanic rocks with ages younger than 5 Ma. After stepwise demagnetization and principal component analysis, site mean remanence directions were computed. Both localities show non-significant clockwise rotations of 1.7° ± 14.4° (Loncopué) and 8.1° ± 8.4° (Andacollo). Although the presently available database does not support significant tectonic rotation of the Andacollo lavas, preliminary results obtained from upper Miocene volcanics in a nearby area indicating ∼20° of clockwise rotation, encourage further studies to improve the resolution of the paleomagnetic data to determine if crustal block rotations have been, or still are, part of the Andean deformational processes. A revision of previously published paleomagnetic data in the northern Patagonian Andes suggests that, against original claims, no significant tectonic rotations associated to the Liquiñe-Ofqui Fault Zone, between ∼39 and 37.5 °S, can be unambiguously demonstrated.

AB - A paleomagnetic study performed in Plio-Pleistocene volcanic rocks of two localities in the Southern Central Andes is presented. The region corresponds to the transition zone between the Central and the Patagonian Andes. In the latter, deformation is almost exclusively controlled by the dextral-strike slip Liquiñe-Ofqui Fault Zone, that extends from ∼47 °S to ∼38 °S and accommodates the deformation generated by the oblique subduction of the Nazca Plate below South America. To the north of ∼36 °S, deformation is mainly contractional. Our study was carried out in the transition zone between both tectonic regimes. Sampling consisted of 31 paleomagnetic sites distributed in two localities: the Loncopué (∼38.0 °S, 70.7 °W) and Andacollo (∼37.2 °S, 70.8 °W) areas. We sampled Pliocene and Pleistocene volcanic rocks with ages younger than 5 Ma. After stepwise demagnetization and principal component analysis, site mean remanence directions were computed. Both localities show non-significant clockwise rotations of 1.7° ± 14.4° (Loncopué) and 8.1° ± 8.4° (Andacollo). Although the presently available database does not support significant tectonic rotation of the Andacollo lavas, preliminary results obtained from upper Miocene volcanics in a nearby area indicating ∼20° of clockwise rotation, encourage further studies to improve the resolution of the paleomagnetic data to determine if crustal block rotations have been, or still are, part of the Andean deformational processes. A revision of previously published paleomagnetic data in the northern Patagonian Andes suggests that, against original claims, no significant tectonic rotations associated to the Liquiñe-Ofqui Fault Zone, between ∼39 and 37.5 °S, can be unambiguously demonstrated.

KW - Cola de Zorro formation

KW - Guañacos formation

KW - Liquiñe-Ofqui

KW - Neogene

KW - Neuquén Andes

KW - Volcanics

UR - http://www.scopus.com/inward/record.url?scp=85149816489&partnerID=8YFLogxK

U2 - 10.1016/j.jsames.2023.104220

DO - 10.1016/j.jsames.2023.104220

M3 - Article

AN - SCOPUS:85149816489

SN - 0895-9811

VL - 124

SP - 1

EP - 17

JO - Journal of South American Earth Sciences

JF - Journal of South American Earth Sciences

M1 - 104220

ER -

New and revised paleomagnetic data from the southern central Andes: Testing tectonic rotations

Abstract

Bibliographical note

Funding

Keywords

Access to Document

Other files and links

Fingerprint

Cite this