This dataset presents the raw data of an experimental series of centrifuge models performed to test the influence of pre-existing weak zones in the lower crust (herein after referred to as Weak Lower Crust –WLC) during continental compression. We varied the width of the WLC, the dip of the interfaces bounding the WLC and the frictional properties at the WLC-LC interface by using lubricant (vaseline).
In this dataset, we provide four different types of data, that can serve as supporting material and can be used for further analysis: 1) The top-view photos, taken at different stages and showing the deformation process of each model; 2) Digital Elevation Models (DEMs) used to reconstruct the 3D deformation of the performed analogue models; 3) Line-drawing of fault and fracture patterns to be used for fault statistical quantification; 4) A Python script to draw swath profiles (outputs) of the analogue models.
Further details on the modelling strategy can be found in the publication associated with this dataset and in Milazzo et al. (2021), using a similar setup for achieving compression in the centrifuge. Materials used for these analogue models were described in Corti (2012), Montanari et al. (2017), Del Ventisette et al. (2019), Zou et al. (2024) and Wan et al. (2025).
This data set includes images and videos depicting the evolution of deformation and topography in 17 analogue experiments of passive margin development, to better understand the ongoing tec-tonics along the western margin of Afar, East Africa. The tectonic background that forms the basis for the experimental design is described in Zwaan et al. 2020a-d, and references therein. The ex-periments, in an enhanced gravity field in a large-capacity centrifuge, examined the influence of brittle layer thickness, strength contrast, syn-rift sedimentation and oblique extension on a brittle-viscous system with a strong and weak viscous domain.
All experiments were performed at the Tectonic Modelling Laboratory of the Istituto di Geoscience e Georisorse - Consiglio Nazionale delle Ricerche (CNR-IGG) and of the Earth Sciences Department of the University of Florence (CNR/UF). The brittle layer (sand) thickness ranged between 6 and 20 mm, the underlying viscous layer, split in a competent and weak domain (both viscous mixtures), was always 10 mm thick. Asymmetric extension was achieved by removing a 1.5 mm thick spacer at the side of the model at every time step, allowing the analogue materials to spread when en-hanced gravity was applied during a centrifuge run.
Differential stretching of the viscous material creates flexure and faulting in the overlying brittle layer. Total extension amounted to 10.5 mm over 7 intervals for Series 1 models that aimed at un-derstanding generic passive margin development in a generic orthogonal extension setting, where-as up to 16.5 mm of extension was applied for the additional Series 2 models aiming to reproduce the tectonic phases in Afar. In models involving sedimentation, sand was filled in at time steps 2, 4 and 6 (i.e. after 3, 6 and 9 mm of extension). Detailed descriptions of the experiments, monitoring techniques and tectonic interpretation of the model results are presented in Zwaan et al. (2020a).