Rock type: carbonate sedimentary.

Age: about 90 million years. Cretaceous (Turonian) period.

Characteristics: composed of grains of sand and fragments of shells from marine organisms (corals or rudists).

Formation environment: shallow and warm waters reef.

Uses: construction materials and sand and gravel.

Origin of the block: Congost d'Erinyà, Senterada (Pallars Jussà).