The Partagat chasms, located at the highest part of the Sierra de Aitana (Province of Alicante), are large
joints which have opened up in Eocene limestone. They measure up to 15-20 metres in width and dozens
of metres in depth. These joints have originated from lateral-spreading, which have evolved with time into
slides. They have formed here along the lines of pre-existing NW-SE and NE-SW fractures, due to the
movement of large blocks of limestone over an underlying layer of marls, both Eocene in age. Throughout
the Quartenary, these landslides caused the mountain front retreat of the Aitana fault, a normal E-W fault
with a throw of several hundred metres