Episodic out-of-sequence deformation promoted by Cenozoic fault reactivation in NW Argentina

Patricio Payrola, Cecilia del Papa, Alejandro Aramayo, Heiko Pingel, Fernando Hongn, Edward R. Sobel, Gerold Zeilinger, Manfred R. Strecker, Sebastian Zapata, John Cottle, Natalia Salado Paz, Johannes Glodny

Research output: Contribution to journalResearch Articlepeer-review

23 Scopus citations

Abstract

The Central Andes are the product of contractional deformation related to subduction of the Nazca plate beneath the South American continent. In this geodynamic setting, thrust belt propagation in the Central Andean retroarc in NW Argentina and southern Bolivia has been linked with the critical wedge model implying progressive eastward migration of the deformation front during the Cenozoic. However, Eocene unconformities and growth strata within the orogenic hinterland of the Eastern Cordillera and Puna Plateau suggest selective reactivation of pre-Andean and Andean faults revealing a pattern of diachronous and spatially disparate range uplifts. The Calchaquí Valley in NW Argentina is characterized by basin-and-range morphology, which is intimately linked with the heterogeneous Neoproterozoic basement, Cretaceous rift structures, and the Cenozoic foreland. In this study, we analyze this complex deformation by reconstructing Cenozoic fault reactivation and sedimentation patterns in the Eastern Cordillera. Detailed structural mapping along the eastern Calchaquí border (Tonco area) reveals five Cenozoic unconformities in the former foreland deposits related to multiple episodes of fault reactivation during the Eocene-to-Pleistocene. A refined chronostratigraphy (U-Pb zircon), new AHe thermochronological data (apatite U-Th-Sm/He), and existing evidence for deformation indicate episodic out-of-sequence deformation and increased Eo-Oligocene (Puna Plateau) to Miocene (Eastern Cordillera) fault displacement apparently controlled by pre-Cenozoic heterogeneities. The coeval eastward propagation of deformation and continuing deformation in the west generally challenge the applicability of the critical wedge model.

Original languageEnglish (US)
Article number228276
JournalTectonophysics
Volume776
DOIs
StatePublished - Feb 5 2020
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Earth-Surface Processes

Fingerprint

Dive into the research topics of 'Episodic out-of-sequence deformation promoted by Cenozoic fault reactivation in NW Argentina'. Together they form a unique fingerprint.

Cite this