GravelScape surface grain size fining for the final 5Myrs at steady-state of a 20Myr simulation with an uplifting orogen (left) draining into a subsiding basin (right). The GravelGSN_DTIME is the grain size at the surface that is updated over time with past deposits still visible if not covered by new deposits. The GravelGSN_DMean highlights the coarser grains deposited in the channels of a given time step.