The environments of deposition of the Upper Rotliegend in the Southern Permian Basin have been of continuing interest since the discovery of the Groningen Gas Field in 1959. This is because the quality of the porosity and permeability of the sands is in most places dependent upon the original depositional environments. In the earliest years, the emphasis of much work was on mapping broad depositional realms of aeolian, fluvial, and playa environments. As new discoveries came under development, the geometry of small-scale features such as dune (good reservoir) and interdune (poor reservoir) became important, informed in part by studies...