The Pale Mountains

The Dolomites are renowned for their scenery. Take time to examine the rocks and you’ll discover that like an onion, the history of this UNESCO World Heritage site is many layered.

  • September 2018

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    Reading time: 4'

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The Pale Mountains

The Dolomites are renowned for their scenery. Take time to examine the rocks and you’ll discover that like an onion, the history of this UNESCO World Heritage site is many layered.

I can already tell that this won't be a hike in the classical sense. As Corrado Morelli walks along the stream bed of the Bletterbachschlucht gorge, he pauses again and again to inspect the ground in front of him. He picks up stones: large, flat, small, round, white and grey. He turns and flips each of one of them, scratches their surfaces, or divides them in half with a small pick. This continues until he has deciphered them to uncover their hidden secrets. “Have a look, " says Corrado, placing one of his study objects in the palm of my hand, “these were once plants.” To my eye, I see a stone and a few little black dots. Where exactly is the plant again? To me, of course, stones are just... well, stones. But to Corrado? He takes a moment to consider my question and all the while he continues to examine the stone. “Valuable witnesses,” he finally says, “because I know where each and every one of these stones comes from.” The shapes, colours and consistencies of the rocks cast him back in time.

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Corrado Morelli is a geologist. Although the Rome native has been living in South Tyrol for 24 years, he says that he only really got to know the Dolomites last year, though he can’t say why. “The Dolomites were for a long time like an unknown beauty. I noticed them, but it took years to really appreciate their story. It’s like a good book and you want to spend the whole summer engrossed in the tale,” he says, trying to explain the matter to himself. In fact, he and his colleagues spent all last summer in the Dolomites developing the “Dolomites UNESCO Geotrail.” The purpose of this long-distance hiking trail is to make the special geological features of the mountain chain more tangible. This, along with the natural beautys, is the reason why the Dolomites have been awarded as a “UNESCO World Heritage Site” since 2009.

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“The history of the origin of the Dolomites can be appreciated most vividly here in the Bletterbachschlucht gorge,” explains Corrado. He points to the steep walls of the gorge. Colourful horizontal layers adorn the up to 400-meter-high rock walls. The higher up one goes, the closer one gets to the present. This is the paradoxical history that’s hidden in the layers of rock. The concept of time is a matter of perspective: Across a few meters of this wall, millions of years of the history of the earth have been pressed together.

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To the Bahamas with the stone time machine

Awestruck, I gaze up at the lines in the rock face. My view next glides up to the nearest peak, the Weißhorn mountain. The Dolomites seem immovable, rooted in place as if they had always existed. Looming tall and mighty, these characteristically rugged rocks and towers spill forth into the valley where they meet the gentle meadows or merge into deep valleys. Corrado must be reading my mind. “That's the hard part of explaining geology. Nobody wonders: How was this mountain formed? In human memory they have just been there,” he says.

The story of the Dolomites began 280 million years ago somewhere else entirely: about 10 degrees north of the equator. “It's been a long journey, with many radical changes,” explains Corrado. Way back then, as part of the Pangaea supercontinent, the Dolomites region was a volcanic, flat mainland. As the supercontinent disintegrated, the volcanic landscape became a coastal plain, submerged and reappeared several times, and formed two new continents (Palaeo Europe and Palaeo Africa) that slowly drifted apart.

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As the sea became deeper and deeper, the coralline algae, sponges and micro-organisms built their reefs ever higher in turn, up to just below the waterline where they could thrive. “This is how the typical brittle, white/light grey Dolomite rock was formed,” explains the geologist. This is likely the reason why the Dolomites were once called the “Pale Mountains.” Corrado sketches the process on a sheet of paper. The drawing depicts a steadily growing hill at the edge of these underwater structures, which steeply descends to a depth of 800 m. “The Dolomite reefs developed into an archipelago similar to the Bahamas or Caribbean archipelago. The Dolomites were like the Bahamas? Corrado nods. In the past, mountains like the Schlern, Latemar mountain range or the Rosengarten massif were once reefs. 240 million years ago there were tropical plants and countless marine animals, dinosaurs bounding along the beach, and volcanoes bubbling up between the reefs. This age ends with climatic changes that prohibited growth. And so the reefs sunk into a deep-sea basin. 

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The mountain’s underwater isolation was long. The Dolomites finally came up for air just 30 million years ago. “The plates of the earth pressed against each other and folded the layers of rock that had formed up to that point like an accordion on the Alps,” says Corrado, forming an inverted V with his hands. Then, he folds his hands apart like a serving tray to illustrate the Dolomites’ most important speciality: “The immense pressure caused many layers of rock in the Alps to meld together. The Dolomites south of the main ridge of the Alps, on the other hand, simply rose like a platform being elevated, and although some of them were moved and tilted over time, the original rock layers have actually been preserved for the most part.” It is easy to reconstruct everything that happened before this time when the area was a coastal plain, shallow water, a lagoon, a reef, an active volcanic landscape and a deep-ocean basin. For science, that’s like getting every number correct in the lottery. 

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An educational experience for all

But what if you don’t have a clue about geology? Not to worry says Corrado: “The Dolomites are like an open book that anyone can read.” Children, with their urge to discover, are often the most intuitive and invent their own stories about each stone. “In fact, all it takes is to open your eyes as wide as possible,” says Corrado. “We geologists do nothing but compare,” he says, “is there a similar stone, a similar material with which I am already familiar? To which age or layer does this stone fit?” For centuries, countless researchers have been working to puzzle out the extraordinary history of these special mountains.

“The beauty of the Dolomites can be experienced hands-on. We want to use the Geotrail to explain how this beauty came about,” explains Corrado. The Bletterbach stream is only the first stage, like the introduction to this colourful volume on the Dolomites. All along the Dolomites UNESCO Geotrail, hikers can now discover and understand the history of the Dolomites’ origins up to the present day. A keen understanding of geology is not required because in the hiking guide to the Geotrail, the processes of the earth's history are described in simple language and are illustrated in detail with pictures and maps. “We have tried to highlight the most exciting outcroppings (unveiled rock for exploration, editor's note) in addition to current phenomena. These points of interest, once connected, form a trail that runs like a red line through the Dolomites,” explains Corrado. During the course of the hike, geological knowledge is built up in layers.

They really do move!

The Dolomites appear to be literally set in stone and yet they refuse to stand still. “Landslides and rockfalls, like the recent one on the Rotwand mountain in Hochpustertal valley, remind us of this every day. These processes are actually quite normal,” confirms Corrado,” but we don't even notice most phenomena because they have a much longer time scale than we humans. The Alps, for example, grow one millimetre in height each year due to the pressure of the Earth's plates, while at the same time there is about one millimetre of erosion. The southern zone of the Alps, where the Dolomites lie, also shifts almost one centimetre northwards every year. Today, terrestrial movements can be measured very precisely with modern satellites. So what happens next? “If the movements continue in their current direction, in about 20 million years the Dolomites will be situated in present day Munich,” explains the geologist. And the Bahamas? “They are going through the same processes as the Dolomites did more than 200 million years ago. Eventually, the Bahamas will become a kind of new Dolomites. But that will take a very, very long time,” laughs Corrado.

Text: Marlene Lobis
Transcreation: Covi, Wurzer & Partner - Die Sprachdienstleister
Photo: Harald Wisthaler, Valentin Pardeller, Thomas Grüner, Tappeiner
Video: Miramonte Film/Andreas Pichler