Cross bedding is a geological term referring to the way a sedimentary deposit is affected by water currents, during its formation. It can also refer to the movement of sand in dunes, under the influence of wind currents. It is a common type of sedimentary structure, in sandstone, other detrital sediments, limestone and dolomite. The migration of material is in the direction of current flow, downstream or downwind under conditions of erosion and deposition. It is a process of erosion, occurring during the process of deposition. It may also be called 'current bedding'. Two types of sedimentary rock: limey shale overlaid by limestone. ... Patterns in the sand Sand is an example of a class of materials called granular matter. ... Mesquite Flat Dunes in Death Valley National Park In physical geography, a dune is a hill of sand built by eolian (wind-related) processes. ... Sandstone near Stadtroda, Germany Sandstone is a sedimentary rock composed mainly of sand-size mineral or rock grains. ... Limey shale overlaid by limestone. ... Dolomite crystals from Touissite, Morocco Dolomite is the name of both a carbonate rock and a mineral (formula: CaMg(CO3)2) consisting of a calcium magnesium carbonate found in crystals. ... Severe soil erosion in a wheat field near Washington State University, USA. Erosion is the displacement of solids (soil, mud, rock, and other particles) by the agents of wind, water, ice, movement in response to gravity, or living organisms (in the case of bioerosion). ... Deposition, also known as sedimentation, is the geological process whereby material is added to a landform. ...