Pre-Andean and Andean Shortening in the Eastern Cordillera of NW Argentina at 23ºS

The Eastern Cordillera, in NW Argentina, is an imbricate thrust system involving Precambrian to Cenozoic stratigraphic units. Structural analysis shows that the Cretaceous unconformity truncates previous thrusts and related folds, but most of the Andean structures result from the reactivation of pre...

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Authors: Alonso Alonso, Juan Luis; Quintana, Luis; Gallastegui Suárez, Jorge|||0000-0002-3819-0183
Format: Article
Publication date:2025
Country:España
Institution:Universidad de Oviedo (UNIOVI)
Repository:RUO. Repositorio Institucional de la Universidad de Oviedo
Language:English
OAI Identifier:oai:digibuo.uniovi.es:10651/82299
Online Access:https://hdl.handle.net/10651/82299
https://dx.doi.org/10.1016/j.jsames.2025.105809
Access Level:Open access
Keyword:Eastern Cordillera
Pre-Andean deformation
Andean reactivation
Thrust and fold reactivation
Pre-Andean shortening
Andean shortening
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author Alonso Alonso, Juan Luis
author2 Quintana, Luis
Gallastegui Suárez, Jorge|||0000-0002-3819-0183
author2_role author
author
author_browse Alonso Alonso, Juan Luis
Gallastegui Suárez, Jorge|||0000-0002-3819-0183
Quintana, Luis
author_facet Alonso Alonso, Juan Luis
Quintana, Luis
Gallastegui Suárez, Jorge|||0000-0002-3819-0183
author_role author
collection RUO. Repositorio Institucional de la Universidad de Oviedo
description The Eastern Cordillera, in NW Argentina, is an imbricate thrust system involving Precambrian to Cenozoic stratigraphic units. Structural analysis shows that the Cretaceous unconformity truncates previous thrusts and related folds, but most of the Andean structures result from the reactivation of pre-Andean thrusts and folds. The total shortening for the Eastern Cordillera is about 46 km, of which 30 km are Andean in age and about 16 km correspond to the original Paleozoic imbricate. A complete cross-section through the Eastern Cordillera and the Interandean Zone at 23◦S is presented and a sequential restoration of Andean and pre-Andean structures was carried out. In this section, two basement sheets, each about 10 km thick, have been inferred below the Eastern Cordillera from displacement transfer analysis. The thrust sequence was established on the basis of quantitative analysis of displacement transfer. The first basement sheet to be emplaced reactivated the floor thrust of the previous Paleozoic imbricate system, and accounts for the cumulative shortening of Andean thrusts in the Eastern Cordillera. The second one developed in forward sequence, transferring more than 60 km to the sole thrust of the Subandean imbricate system. It is the main thrust and gave rise to the uplift and deep exhumation of the primitive Eastern Cordillera, causing a fast increase in subsidence rates in the Subandean foreland basin. Later, a second movement of the first basement sheet transferred about 8 km of displacement towards several out-of-sequence thrusts, giving rise to the inter-montane Humahuaca Basin.
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language eng
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network_name_str España
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publishDate 2025
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spelling Pre-Andean and Andean Shortening in the Eastern Cordillera of NW Argentina at 23ºS Alonso Alonso, Juan Luis Quintana, Luis Gallastegui Suárez, Jorge|||0000-0002-3819-0183 Eastern Cordillera Pre-Andean deformation Andean reactivation Thrust and fold reactivation Pre-Andean shortening Andean shortening The Eastern Cordillera, in NW Argentina, is an imbricate thrust system involving Precambrian to Cenozoic stratigraphic units. Structural analysis shows that the Cretaceous unconformity truncates previous thrusts and related folds, but most of the Andean structures result from the reactivation of pre-Andean thrusts and folds. The total shortening for the Eastern Cordillera is about 46 km, of which 30 km are Andean in age and about 16 km correspond to the original Paleozoic imbricate. A complete cross-section through the Eastern Cordillera and the Interandean Zone at 23◦S is presented and a sequential restoration of Andean and pre-Andean structures was carried out. In this section, two basement sheets, each about 10 km thick, have been inferred below the Eastern Cordillera from displacement transfer analysis. The thrust sequence was established on the basis of quantitative analysis of displacement transfer. The first basement sheet to be emplaced reactivated the floor thrust of the previous Paleozoic imbricate system, and accounts for the cumulative shortening of Andean thrusts in the Eastern Cordillera. The second one developed in forward sequence, transferring more than 60 km to the sole thrust of the Subandean imbricate system. It is the main thrust and gave rise to the uplift and deep exhumation of the primitive Eastern Cordillera, causing a fast increase in subsidence rates in the Subandean foreland basin. Later, a second movement of the first basement sheet transferred about 8 km of displacement towards several out-of-sequence thrusts, giving rise to the inter-montane Humahuaca Basin. https://hdl.handle.net/10651/82299 https://dx.doi.org/10.1016/j.jsames.2025.105809
spellingShingle Pre-Andean and Andean Shortening in the Eastern Cordillera of NW Argentina at 23ºS
Alonso Alonso, Juan Luis
Eastern Cordillera
Pre-Andean deformation
Andean reactivation
Thrust and fold reactivation
Pre-Andean shortening
Andean shortening
title Pre-Andean and Andean Shortening in the Eastern Cordillera of NW Argentina at 23ºS
title_full Pre-Andean and Andean Shortening in the Eastern Cordillera of NW Argentina at 23ºS
title_fullStr Pre-Andean and Andean Shortening in the Eastern Cordillera of NW Argentina at 23ºS
title_full_unstemmed Pre-Andean and Andean Shortening in the Eastern Cordillera of NW Argentina at 23ºS
title_short Pre-Andean and Andean Shortening in the Eastern Cordillera of NW Argentina at 23ºS
title_sort Pre-Andean and Andean Shortening in the Eastern Cordillera of NW Argentina at 23ºS
topic Eastern Cordillera
Pre-Andean deformation
Andean reactivation
Thrust and fold reactivation
Pre-Andean shortening
Andean shortening
topic_facet Eastern Cordillera
Pre-Andean deformation
Andean reactivation
Thrust and fold reactivation
Pre-Andean shortening
Andean shortening
url https://hdl.handle.net/10651/82299
https://dx.doi.org/10.1016/j.jsames.2025.105809