Volcaniclastic clasts have a poor preservation potential in aeolian environments because the processes of abrasion and attrition during wind transport are too severe for the relatively fragile grains to survive. Preservation of ashes is favoured by low-energy continental environments where there is active sediment accumulation, such as lakes, which provide ideal conditions for the preservation of an ash fall deposit in a stratigraphic succession. Floodplain environments may also be suitable but pedogenic and weathering processes will rapidly alter the volcanic material. Ash bands also occur bedded with coals in swamps and mires where organic detritus is rapidly accumulating