panhole

thumbnail|Panholes on a granite surface near Corscia, Corsica A panhole is a depression or basin eroded into flat or gently sloping cohesive rock. Similar terms for this feature are gnamma or rock holes (Australia), armchair hollows, weathering pans (or pits) and solution pans (or pits).

Some authors refer to panholes also as potholes, which is a term typically used for similarly shaped riverine landforms. In fluvial geomorphology, the term pothole is typically used for a smooth, bowl-shaped or cylindrical hollow, generally deeper than wide, found developed in the rocky bed of a stream. This type of feature is created by the grinding action either of a stone or stones or of coarse sediment whirled around and kept in motion by eddies or the force of the stream current in a given spot.