* Petrifying springs with tufa formation (Cratoneurion)
Seepage, rheocrene, or vauclusian springs with water rich in calcium bicarbonate and where deposits of calcium carbonate (tufa) are formed immediately adjacent to the emerging spring in woodlands or in open areas. Lime-encrusted moss mats of the Cratoneurion often occur. This type includes headstreams where these are tufa forming.
Notes on habitat mapping
The assignment to this habitat type is based on obvious tufa formation. The delimitation is to include all areas directly related to the spring as well as all areas hosting the relevant vegetation (Cratoneurion), even where this spreads from the spring head to the upper reaches of the watercourse. Small local and fragmented examples within calcareous fen complexes are to be assigned to habitat type 7230 and are not recorded separately.