cdem: A macOS program for discrete element modeling of tectonic structures

cdem is a macOS document-based application for two-dimensional discrete element modeling of tectonic structures and their associated deformation. Documents encapsulate simulations that can be run and explored simultaneously. A document contains three main views: (1) Set-up view, to define the assembly size, element properties, anisotropy, boundary conditions (type of faulting), overburden stress, erosion, and syn-tectonic sedimentation; (2) Summary view, which displays the details of the model after initialization; and (3) Results view, which displays the geometry of the model while it is running or after the run and allows exploring the model’s evolution in terms of geometry, displacement, strain, or stress. We illustrate the use of the program for assembly calibration and the modeling of contractional and extensional structures without and with syn-tectonic sedimentation. In all these cases, cdem produces realistic incremental and finite deformation. cdem is less powerful than its precursor cdem2D, but it can import and visualize cdem2D results, making the combined use of these two programs a robust suite for mechanically modeling tectonic structures.