DVC and 3D stereo DIC data from analogue models exploring interaction of viscous flow and surface deformation in rotational rift systems

This dataset includes surface 3D stereoscopic Digital Image Correlation (3D stereo DIC) images and videos of 10 analogue models on crustal scale rifting with a rotational component. In addition, this dataset provides CT imagery of four analogue models that have been analyzed by means of Digital Volume Correlation (DVC) applied on X-Ray computed tomography volumes. Data of CT scanned models also includes slices of the volumetric displacement set for each displacement component. Using a brittle-viscous two-layer setup, the experiments focused on surface rift propagation, internal viscous flow driven by a horizontal pressure gradient and the interaction of internal and surface deformation. All experiments were performed at the Tectonic Modelling Laboratory of the University of Bern (UB). 3D stereo DIC analyses were performed at the GFZ German Research Centre for Geosciences (GFZ) and DVC analyses were performed at the Royal Holloway University London (RHUL). All models consist of a two-layer brittle-viscous set up with a total thickness of 6 cm. Thickness variations in brittle and ductile layers are expressed by the ratio RBD = brittle layer thickness/ductile layer thickness, which ranges from RBD = 0.5 to RBD = 2. The model set up lies on top of a 5 cm thick foam base with a trapezoidal shape with a height of 900 mm and a pair of bases with widths of 310 mm and 350 mm at the far ends, respectively. The foam block is sliced into segments such that 7 interlayered 0.5 cm thick plexiglass bars prevent foam collapse under the model weight. Before model construction, the foam-plexiglass assemblage is placed between longitudinal side walls. The experimental set-up is such that rotational extension in one part of the model domain is separated from rotational shortening in the other part of the model domain by a vertical rotation axis (Fig. 1). During the model run, the foam homogeneously expands in the domain undergoing extension and homogeneously contracts in the domain undergoing shortening. The applied velocity for all models is 10 mm/h and refers to the divergence of the sidewalls furthest away from the rotation axis which decreases linearly towards the rotation axis. This results in a maximum displacement of 40 mm at the outermost circular segment after a total run time of 4h.