Description: The southern Andes are regarded as a typical subduction orogen formed by oblique plate convergence. Despite decades of studies, there is considerable uncertainty as to how deformation is kinematically partitioned in the upper plate. Using scaled analogue experiments modelling, we test the concept of dextral transpression for this orogen. We advocate that the GPS velocity field portrays interseismic deformation related to deformation of strong crust north, and weak crust south, of 37°S. Contrary to the popular hypotheses that the Liquiñe-Ofqui Fault Zone, a prominent intra-arc deformation zone, takes up most of the plate boundary-parallel dextral strike-slip, we find that dextral transpression affects the entire model orogen through tectonic segmentation of crust. Moreover, prominent, regularly spaced sinistral oblique-slip thrust faults, interpreted as antithetic Riedel shears, developed spontaneously in all of our experiments and call into question the general believe that their NW-striking natural equivalents formed from pre-Andean discontinuities. Our experiments prompt us to reconsider the apparently well-established geodynamic concept that strain and margin-parallel displacement is localized on a few margin-parallel faults in the southern Andes.
Global identifier:
Doi(
"10.5880/fidgeo.2021.023",
)
Origins: /Wissenschaft/Helmholtz-Gemeinschaft/GFZ
Tags: Modellierung ? Daten ? Studie ? Time lapse camera ? European Plate Observing System ? GPS velocity field ? Glass/Plexiglas box > Glass/Plexiglas box (meter scale) ? Liquiñe-Ofqui Fault Zone ? Microspheres > Glassy ? Multibox ? Sand > Corundum Sand ? Sand > Quartz Sand ? Sandbox > Sandbox (meter scale) ? Shear box ? Silicon/Silly putty/PDMS ? Southern Andes ? Squeeze box ? Strain partitioning ? Surface image ? EARTH SCIENCE > SOLID EARTH > GEODETICS ? Transpression ? analog modelling results ? analogue experiment ? analogue models of geologic processes ? fault > oblique slip fault ? fault > strike-slip fault ? geologic process ? interseismic deformation ? kinematic partitioning ? multi-scale laboratories ? normal fault ? oblique plate convergence ? tectonic and structural features ? tectonic process > orogenic process ? tectonic setting > back arc setting ? tectonic setting > plate margin setting > active continental margin setting ? tectonic setting > plate margin setting > volcanic arc setting ? EARTH SCIENCE > SOLID EARTH > TECTONICS > PLATE TECTONICS > STRAIN ? EARTH SCIENCE SERVICES > MODELS > GEOLOGIC/TECTONIC/PALEOCLIMATE MODELS ? EPOS ? Digital Image Correlation (DIC) / Particle Image Velocimetry (PIV) > StrainMaster (La Vision GmbH) ?
License: cc-by/4.0
Language: Englisch/English
Issued: 2021-01-01
Time ranges: 2021-01-01 - 2021-01-01
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