Movie A-1. Shortening experiment SchreursG. HänniR. PanienM. VockP. 2019 Movie showing the cross-sectional evolution of structures in the brittle domain. The faults correspond to zones of dilation with lower X-ray attenuation compared to the adjacent unfaulted material. Thrust faults are closely spaced and form a narrow and high fold-and-thrust belt. Thrust faulting occurs in-sequence. Each section represents a 2 mm thick X-ray computed tomography (CT) slice that was acquired parallel to the shortening direction. Initial width of the model was 27 cm, whereas the initial height was 3 cm. Shortening increment between frames is 1 cm. The visualization of individual layers improves as shortening progresses, because the algorithms used to compute the CT slices are optimized for round-shaped objects. Quartz sand = medium grey, corundum sand = light grey.