The origins of the Dolomites
Their history dates back 250 million years
The ancient history of the Dolomites began in the Triassic Period, about 250 million years ago. It may seem unimaginable, but where the majestic peaks of the “Monti Pallidi” (Pale Mountains) rise today, in that period there was a warm, shallow, calm tropical sea.
Over millions of years, the shells, corals and calcareous algae that slowly accumulated on the sea floor created atolls and coral reefs. It was very similar to the sea we see today around the Bahamas or eastern Australia, although the landscape was often ravaged by terrifying volcanic eruptions.
In the Jurassic Period, when large dinosaurs dominated the Earth, the sediment that accumulated on the seabed formed a layer of hundreds of metres that was compacted due to its weight, which then became solid limestone rock.
In more recent times, starting from about 20 million years ago, the collision of the African and European tectonic plates deformed these ancient rocky sea floors, creating mountains even more than 3.000 metres high. Earthquakes, volcanic eruptions and the erosive force of wind, ice and rain finally sculptured the characteristic Dolomite landscape, creating a multitude of spires, towers, cliffs and pinnacles, also shaping cornices, edges, overhangs and plateaus.
The Dolomites are therefore the extraordinary result of an ongoing geological process, which is still in progress today. During an excursion you can see signs of their turbulent past everywhere. The Sella mountain group, for example, which today towers majestically over the surrounding landscape, rose up from a single ancient coral reef.
As you venture into the Bletterbach Gorge, a 400-metre-deep canyon near Val di Fiemme, within walking distance from Aldino or Redagno, you can retrace the last 40 million years of the Dolomites’ geological history simply by gazing up from the bottom towards the top at the succession of rock layers.
Even the romantic warm red colour that often tinges the peaks at dawn or sunset proves the ancient coral origin of the Dolomites. It is in fact the particular composition of these sedimentary rocks, composed primarily of calcium and magnesium carbonate, that is the dolomite mineral, which causes the fascinating enrosadira(alpenglow) phenomenon. This discovery was made by Marquis Déodat de Dolomieu (1750-1801), an important French naturalist, after whom the Dolomites were named.