Nine sandstone beds, ranging in thickness from a few inches to almost 25 ft, characterize the upper half of the Late Devonian Arrow Canyon Formation in the Arrow Canyon quadrangle. These sandstone bodies are composed of well-sorted, rounded quartz grains. Similarly sorted calcareous pellets are present in some of the sandstone and apparently constitute most of the dominantly carbonate rock of the upper Arrow Canyon Formation. Most of the sandstone layers are continuous within the quadrangle. Similar sandstones are common in the eastern Great Basin along the eastern boundary of the miogeosyncline, with a major concentration in the region of the Great Salt Lake. Directional indicators in the Arrow Canyon quadrangle indicate predominant sediment movement toward the southwest along the geosynclinal margin. The environment of deposition appears to have been relatively quiet water, but with sediments supplied from a region of more intense agitation.