Downslope coarsening in aeolian grainflows of the Navajo Sandstone

► We sampled individual grainflows in friable outcrops of the Navajo Sandstone. ► Samples were analyzed with a laser granulometer. ► Grainflows coarsen downslope, and are not inverse graded. ► Downslope coarsening sequesters coarse grains if dune deposits are truncated. ► At dune field's downwind margin, coarse grains must have had a local source.