Weakly developed
These photos are examples of weakly developed pedological organisation with poorly expressed horizonation. These soils classify as either Rudosols or Arenosols.
All these images show soil materials with little, if any pedological organisation. The arid unstable sand dune is >1 m deep, and therefore classifies as an Arenosol. If the sand was less than 1m deep, it would classify as a Rudosol.