TY - JOUR
T1 - Episodic out-of-sequence deformation promoted by Cenozoic fault reactivation in NW Argentina
AU - Payrola, Patricio
AU - del Papa, Cecilia
AU - Aramayo, Alejandro
AU - Pingel, Heiko
AU - Hongn, Fernando
AU - Sobel, Edward R.
AU - Zeilinger, Gerold
AU - Strecker, Manfred R.
AU - Zapata, Sebastian
AU - Cottle, John
AU - Salado Paz, Natalia
AU - Glodny, Johannes
N1 - Funding Information:
This work was supported by PICT 2245-15 , Strategy CONICET-Potsdam University , PICT 2016-1274 grants, and Regional Noroeste – Comisión Nacional de Energía Atómica ( CNEA ). We thank the people of the Tonco Valley for their kindness and hospitality during our fieldwork and the Administración de Parques Nacionales and its guards for granting access to the Parque Nacional Los Cardones. This work was considerably improved thanks to the suggestions of P. Agard, D. Pearson, anonymous reviewer, J. Kley, L. Schoenbohm, V. Georgieva and V. García.
Funding Information:
This work was supported by PICT 2245-15, Strategy CONICET-Potsdam University, PICT 2016-1274 grants, and Regional Noroeste – Comisión Nacional de Energía Atómica (CNEA). We thank the people of the Tonco Valley for their kindness and hospitality during our fieldwork and the Administración de Parques Nacionales and its guards for granting access to the Parque Nacional Los Cardones. This work was considerably improved thanks to the suggestions of P. Agard, D. Pearson, anonymous reviewer, J. Kley, L. Schoenbohm, V. Georgieva and V. García.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/2/5
Y1 - 2020/2/5
N2 - 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.
AB - 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.
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U2 - 10.1016/j.tecto.2019.228276
DO - 10.1016/j.tecto.2019.228276
M3 - Article
AN - SCOPUS:85077788695
SN - 0040-1951
VL - 776
JO - Tectonophysics
JF - Tectonophysics
M1 - 228276
ER -