Stop for a close look at the rock
The Brenta mountains consist largely of Dolomite, a mineral found in limestone rock — rock formed by the sedimentation of marine organisms — which is susceptible to being eaten away by weather conditions, forming great scree cones at the base of the mountain walls.
Dolomite is formed by the conversion of limestone (Calcium carbonate - CaCO3), typical of the Prealps, into a double carbonate of calcium and magnesium CaMg(CO3)2 by replacement. This chemical process takes tens of thousands of years, and occurs exclusively in marine environments with high levels of salt and shallow seabeds or lake basins that were once open sea.
You must remember that the Dolomites were once similar to today’s Pacific atolls: islands surrounded by seabeds colonised by coral. The immense biodiversity of this environment included algae, molluscs and fish during the Permian period, 280 million years ago. When the organisms that lived in this warm environment died, their remains were deposited on the sea floor and, over millions of years, were transformed from sediment to rock.
If you walk towards the Agostini lodge along the “Castiglioni” Via Ferrata, you will notice that the rock beneath your feet seems to be full of holes and markings. Pick up a stone and look closely at it: all those tiny markings are what’s left of the ancient corals that once formed the atoll.