The Central Andes (~21°S) is a subduction-type orogeny formed in the last ~50 Ma from the subduction of the Nazca oceanic plate beneath the South American continental plate. However, the most important phases of deformation occur in the last 20 Ma. Pulses of shortening have led to the sudden growth of the by the Altiplano-Puna plateau. Previous studies have provided insights on the importance of various mechanisms on the overall shortening such as the weakening of the overriding plate from crustal eclogitization and delamination, or the importance of a relatively high friction at the subduction interface, and weak sediments in foreland. However none of them has addressed the mechanism behind these shortening pulses yet. Therefore, we built a series of high resolution 2D visco-plastic subduction models using the ASPECT geodynamic code, in which the oceanic plate is buoyancy-driven and the velocity of the continent is prescribed. We have also implemented a realistic geometry for the south American plate at ~30 Ma. We propose a new plausible mechanism (buckling and steepening of the slab) as the cause of these pulses. The buckling leads to the blockage of the trench. Consequently, the difference of velocity between the South American plate and the trench is accommodated by shortening. The data presented here includes the parameters files, for the reference model (S1) and the following alternative simulations: models with variation of the friction at the subduction interface (S2a-c), a model without eclogitization of the lower crust (S3) and a model with higher thermal conductivity of the upper crust (S4). Additionally, this publication includes the initial composition and thermal state of the lithosphere used for the models and a Readme file that gives all the instructions to run them.
This data publication includes geologic-map and structural-field data that complement a structural analysis of intra-montane basins of the southwestern Tian Shan of Central Asia. The southwestern Tian Shan is defined as that part of the Tian Shan west of the Talas-Fergana Fault Zone that is located at the junction with the Pamir and the Afghan-Tajik Basin and stretches to the Fergana Basin in the north. It also includes an ArcGIS-Geodatabase with the shapefiles of the digitized stratigraphy and faults for the regional geological maps. The data are supplementary material to Trilsch et al. (2025): “Southwestern Tian Shan: 1. Deformation of Cenozoic Intra-montane Basins and Intervening Basement Ranges in Front of the Indian Mantle Indenter” (Tectonics; doi: added when published).
One Figure, provided as pdf file and ArcGIS shapefiles, provides a map of the southwestern Tian Shan that compiles structures that were active or potentially-active during the Cenozoic. Reliable Cenozoic structures affect Mesozoic-Cenozoic strata; potentially-Cenozoic ones displace younger over older Paleozoic strata, or show opposite vergence within a sequence of consistently-verging Paleozoic nappes. The other figures provide maps, structural-data stereoplots, field pictures, and outcrop sketches of several intra-montane basins of the southwestern Tian Shan. The supplementary material is useful for researchers aiming to study the geoscience of the western (Tajik, Uzbek, Kyrgyz) Tian Shan.
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.
This dataset includes video sequences and strain analysis of 12 analogue models studying crustal-scale deformation and basin reactivation, performed at the Laboratory of Tectonic modelling of the University of Rennes 1. These models show how parameters such as crustal strength, tectonic inheritance and boundary conditions (ishortening/ stretching) control both the distribution of crustal strain and the possibility for pre-existing structures to be reactivated. This dataset includes top-view movies of the 12 models, including strain analysis based on displacement vectors obtained from digital image correlation. Detailed descriptions of models can be found in Guillaume et al. (2022, special issue of Solid Earth on Analogue modelling of basin inversion) to which this dataset is supplementary.