1. From 42 to 37 million-years (mid Eocene, basically) a narrow sea spread to the area of Bages. This sea was connected to a big gulf of the Atlantic ocean. In this shallow sea, the muddy and sandy sediments which in the future would be the components of the Bages subsoil were accumulated. (1st map)
The coast was on the south of the region. The places where nowadays the massifs of Montserrat and Sant Llorenç del Munt are found were, in that epoch, deltas that were made up by the sediments coming from a mountain range of the Catalonian massif, a continental area that was located in the current Mediterranean sea.
Coral reefs with a really diverse fauna grew on coastal areas with water temperature similar to that of the current Caribbean sea (2nd map).
[drawings Oriol Oms]