This dataset includes the results of 5 lithospheric-scale, brittle-ductile analogue experiments of extension and subsequent shortening performed at the Geodynamic Modelling Laboratory at Monash University (Melbourne, Australia). Here we investigated (1) the influence of the mechanical stratification of the model layers on rift basins during extension and (2) the influence of these basins on shortening-related structures. This dataset consists of images and movies that illustrate the evolution of topography (i.e., model surface height) and cumulative and incremental axial strain during the experiments. Topography and strain measures were obtained using digital image correlation (DIC) which was applied to sequential images of the model surface. This dataset also includes orthophotos (i.e., orthorectified images) of the model surface, overlain with fault traces and basins that were interpreted using QGIS. The experiments are described in detail in Samsu et al. (submitted to Solid Earth), to which this dataset is supplementary.
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.