Crowned pillars or witch’s chimneys

The crowned pillars or witch’s chimneys are worldwide known by the French expression “dames coiffées“, this is ladies wearing caps. They are sculpted by the erosion of poor coherent, heterometric geological materials. Water takes away the materials which are not protected by big blocks. Beneath the big blogs, the pillar grows as the erosion progresses. The process finishes suddenly when the block or hat falls down because the wear of the column.

The pictures display the crowned pillars near the castle of Balsareny, next to the dam in river Llobregat that gives birth to the channel of Manresa. They were originated by the sediments that slipped down the slope (colluvia).

Also materials from volcanic and glaciar source can originate crowned pillars. In Bages district, there are artificial crowned pilars as well in the dump hills of salt residues from potash mines. The process to create crowned pillars performs also at small, centimetric scale with small stones. At much bigger scale, it is responsible for the tabular geomorphology, the type of relief that is found in a main part of Bages district.

[photos Florenci Vallès]