Bunter beds are sandstone deposits containing rounded pebbles. They can be found in Warwickshire, Cheshire, Staffordshire, Nottinghamshire, Yorkshire, Devon and Dorset in England. They are thought to be alluvial deposits and, judging from the rounding of the mainly quartzite pebbles, to have resulted from prolonged transportation in a large and turbulent river, resulting in powerful abrasion. The deposits in the English Midlands are thought to have been transported in this way northwards from Brittany, France. This supposed river has been called the "Budleighensis", after the Devon village of Budleigh Salterton, a site where such deposits were discovered. The depositions took place in the lower Triassic period. Some newer conglomerates, e.g. near Ryton in Warwickshire, are thought to have arisen during the Ice Age by reworking and southward transportation of older deposits by ice flows.

The Buntsandstein (German for coloured or colourful sandstone) or Bunter sandstone is a lithostratigraphic and allostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Buntsandstein predominantly consists of sandstone layers of the Lower Triassic series and is one of three characteristic Triassic units, together with the Muschelkalk and Keuper that form the Germanic Trias Supergroup.