6. An ever more varied marine environment

Some 238-233 million years ago – the late Anisian and early Ladinian eras

The Dolomite region was sinking more rapidly while the upward growth of the bio-constructed islands continued apace.

Thus was formed an archipelago resembling the current Caribbean or Polynesian sea, with underwater escarpments reaching depths of over 1,000 metres. At this time the Dolomite region was sinking ever more dramatically creating areas of deeper sea. In this new environment the organisms from which the islands were constructed multiplied and the sinking of the region forced these tenacious organisms to adapt specifically to keep pace. The vital necessity of remaining near the surface for access to light and a suitable temperature made these organisms group together on top of one another, thus adding to the island’s height. This made it possible for the islands at the western gulf of the Tethys Ocean to achieve a notable size, particularly height. During this period the islands grew at a rate of approximately 1000 metres every million years. The islands of the archipelago featured steep underwater ramps and a muddy interior lagoon surrounded by cliffs. At a certain point the islands also began to grow in width as there was a temporary lull in the rate at which the region was sinking. If you imagine drying out this sea, you would see a flat landscape in places seemingly cut into steps and punctuated by some tall, narrow formations.

Text by Dolomiti Project

Some rocks and fossils from this era