Late pleistocene to recent deformation in the thick-skinned fold-and-thrust belt of Northwestern Argentina (Central Calchaqui Valley, 26 degrees S)
- The thick-skinned fold-and-thrust belt on the eastern flank of the Andean Plateau in northwestern Argentina (NWA) is a zone of active contractional deformation characterized by fault-bounded mountain ranges with no systematic spatiotemporal pattern of tectonic activity. In contrast, the thin-skinned Subandean fold-and-thrust belt of northern Argentina and southern Bolivia is characterized primarily by in-sequence (i.e., west to east) fault progression, with a narrow zone of Quaternary deformation focused at the front of the orogenic wedge. To better understand how recent deformation is accommodated across these mountain ranges and the Argentinian portion of the orogen in particular, estimating and comparing deformation rates and patterns across different timescales is essential. We present Late Pleistocene shortening rates for the central Calchaqui intermontane valley in NWA associated with at least three episodes of deformation. Global Positioning System data for the same region reveal a gradual decrease in horizontal surfaceThe thick-skinned fold-and-thrust belt on the eastern flank of the Andean Plateau in northwestern Argentina (NWA) is a zone of active contractional deformation characterized by fault-bounded mountain ranges with no systematic spatiotemporal pattern of tectonic activity. In contrast, the thin-skinned Subandean fold-and-thrust belt of northern Argentina and southern Bolivia is characterized primarily by in-sequence (i.e., west to east) fault progression, with a narrow zone of Quaternary deformation focused at the front of the orogenic wedge. To better understand how recent deformation is accommodated across these mountain ranges and the Argentinian portion of the orogen in particular, estimating and comparing deformation rates and patterns across different timescales is essential. We present Late Pleistocene shortening rates for the central Calchaqui intermontane valley in NWA associated with at least three episodes of deformation. Global Positioning System data for the same region reveal a gradual decrease in horizontal surface velocities from the Eastern Cordillera toward the foreland, which contrasts with the rapid velocity gradient associated with a locked decollement in the Subandean Ranges of southern Bolivia. Our new results represent a small view of regional deformation that, when considered in combination with the shallow crustal seismicity and decadal-scale surface velocities, support the notion that strain release in NWA is associated with numerous slowly deforming structures that are distributed throughout the orogen.…
Author details: | Sara Figueroa VillegasORCiDGND, Jonathan R. WeissORCiD, Fernando D. HongnORCiD, Heiko PingelORCiDGND, Leonardo EscalanteORCiD, Leonardo ElíasORCiD, R. Germán Aranda-VianaORCiD, Manfred StreckerORCiDGND |
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DOI: | https://doi.org/10.1029/2020TC006394 |
ISSN: | 0278-7407 |
ISSN: | 1944-9194 |
Title of parent work (English): | Tectonics / American Geophysical Union, AGU ; European Geophysical Society, EGS |
Publisher: | American Geophysical Union |
Place of publishing: | Washington, DC |
Publication type: | Article |
Language: | English |
Date of first publication: | 2020/12/06 |
Publication year: | 2020 |
Release date: | 2023/06/28 |
Volume: | 40 |
Issue: | 1 |
Article number: | e2020TC006394 |
Number of pages: | 20 |
Funding institution: | CONICET (Consejo Nacional de Investigaciones Cientificas y Tecnicas)Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) [PUE-IBIGEO 22920160100108CO, PICT 1928, CIUNSa 2336]; German Research Foundation (DFG)German Research Foundation (DFG) [373/34-1]; Brandenburg Ministry of Sciences, Research and Cultural Affairs, Germany; German-Argentine University Network (DAHZ/CUAA); Deutscher Akademischer AustauschdienstDeutscher Akademischer Austausch Dienst (DAAD); CONICETConsejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET); Natural Environmental Research Council (NERC) through the Centre for the Observation and Modeling of Earthquakes, Volcanoes and Tectonics |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Peer review: | Referiert |
Publishing method: | Open Access / Hybrid Open-Access |
License (German): | CC-BY-NC - Namensnennung, nicht kommerziell 4.0 International |