Dolostone, or dolomite, or dolomitic rock, is a carbonate rock made up of the mineral dolomite - calcium-magnesium carbonate - that is secondarily derived from limestone. Although dolostones may be found in other places too, only these mountains are called the Dolomites, after the English naturalist who first identified the connection with the mineral dolomite, which a Swiss student, in turn, named after the French geologist Dolomieu.

The rocks of the Dolomites are not only made of dolomite. Many famous mountain peaks consist of 'simple' massive limestone, calcium carbonate (CaCO3) characterized by scarce or even absent stratification. The remains of those organisms (algae, bacteria, molluscs, corals, sponges) which once formed the carbonate platforms deposited as calcareous mud on the sea floor and then solidified into compact rock over time. 

All of a sudden, long cracks began to form in the sea bed erupting huge quantities of lava that quickly turned to stone when coming into contact with the cold sea water. Despite the rapidity of the process, a few minerals managed to crystallise and may be observed in the dark matrix of the rock. In a few areas (Val di Fassa), volcanic activity was so intense that volcanic edifices rising out of the water were formed.

This natural asset is part of the tour "Browsing through the rocks of the Secëda mountain".

Submarine volcanic activity enriched water with silica (SiO2), allowing organisms with siliceous skeleton (such as radiolaria and sponges) to thrive. Their remains got mixed up with the calcareous mud at the bottom of the deep basins and were later dissolved by the waters circulating into the forming rock. Yet the dissolved silica remained inside the rock, eventually concentrating as chert nodules in the limestone.

This natural asset is part of the tour "Browsing through the rocks of the Secëda mountain".

Severe erosion of rocks by streams and rivers creates gravel and pebbles that are rounded off by the swirling water. These coarse clastic deposits can also go through a natural cementation process to form a conglomerate. The different colours of the debris indicate a wide source area featuring many different types of rock. 

This natural asset is part of the tour "Browsing through the rocks of the Secëda mountain".

Gypsum rock layers originate in a natural salt flat, a very shallow marine environment in a warm, dry climate. Evaporation concentrates salts in sea water until they precipitate, starting with sulphates (gypsum is CaSO4, calcium sulphate). The white layers that can be seen from the Seceda cable car are precisely the remains of these natural salt flats. 

This natural asset is part of the tour "Browsing through the rocks of the Secëda mountain".

The sand that was formed due to the erosion of red porphyry could only be red. It covered a wide plain featuring rivers and lakes surrounded by vegetation and inhabited by primitive reptiles and amphibians at a time when the sea had not yet reached the Val Gardena area. After millions of years, the sand naturally hardened to become sandstone, a firm yet workable rock which may be carved. 

This natural asset is part of the tour "Browsing through the rocks of the Secëda mountain".

How often have you driven along a road paved with blocks of porphyry without realising that this rock was formed from the rapid cooling of lava! This mostly reddish volcanic rock in the Bolzano province makes up a thick bedrock which is the base of the sedimentary sequence. It can be seen along the motorway north of Bolzano or on the Resciesa ridge in Val Gardena.