Monday, 29 June 2015

Time for a Nappe

The Alps span over 1000km and straddle eight countries - I passed through three of them on my Alpine journey: Switzerland, Austria, and Italy. I was based in the latter, where it borders Austria, in an area that has been fought over by Italy and Austria for hundreds of years. During the second world war, Mussolini and Hitler struck a deal where German speakers in this region of northern Italy had to either switch to speaking Italian, or move to Austria (then part of Nazi-Germany). As a result, families were split apart, including my own, and German-speaking South Tyrolean children found themselves being taught at school in a language they didn't speak. Now officially a bilingual province, South Tyrol remains ferociously independent and retains a unique mountain culture. 

Looking South to Italy from a high mountain pass.
These man-made borders mean little to the vast tectonics plates shifting below. There are folds, faults and crumples splitting up the earth here, but much of it is lost under forested slopes, or beneath human settlement. Once you start looking at rocks, even as an amateur, you begin to see how different they can be on neighbouring mountains. From the pale crumbling granite slopes of Mount Ifinger, I looked back to see the low hillside directly opposite burning red in the sunshine. I walked across the join between them, finding the red was a rich sandstone. How did these completely different rocks end up pressed together in this way?
The pale large-grained granite in the foreground contrasts with the vivid red sandstone beyond.
The chunky Ifinger granite is quite unlike the predominant schist of the rest of the valley. This is because it is on the other side of a tectonic divide between less deformed crusts and the heavily metamorphosed central alpine nappes to the north. Most of the area is Permo-Mesozoic in age, dominated by glittering schists streaked with red and yellow. The highest peaks - directly opposite the mountains I was ascending - were formed in a high-pressure squish, generating spectacular rugged pinnacles that harbour snow well into the summer.

Beautiful schists, with some kind of moth/butterfly larvae for scale.

Wonderful metamorphised rock, weathering by the track.
I was lucky enough to come across two geological phenomenon I was keen to find on this trip: garnets and fossils. The former can be massive and abundant in certain areas. I even found one to take home and add to my modest geology collection. As for fossils, metamorphism has destroyed much of what would have once existed in these rocks, but plant material can still be found. There is a museum dedicated to specimens found in a local quarry in Mรถlten, but the ones I came across were part of the collection of a family living on a high mountain pass near Austria.
Big red garnets dot the rocks near the Jaufenpass.
Black fossil plant material, with green lichen encrusting.
The final geological spectacle I'd been intent on seeing were the "earth pyramids". Despite having visited this area for years I only recently found out this phenomenon could be seen all over South Tyrol. Earth Pyramids are caused by selective erosion of glacial moraine. Where there are large rocks in the matrix, they form a kind of umbrella that prevents erosion by rainfall, leaving a pinnacle of earth and rock underneath them. The makes for a dramatic landscape feature.

Once you know what to look for, these earth pyramids can be seen all over the place - although some are more impressive than others. Much larger ones called the Pyramids of Renon, were too far for me to travel this time, so I sought out some more modest ones around Meran.

Photographed from a cable car as it drifted overhead, these earth pyramids are just above the city of Meran. They are especially pale and the amount of vegetation on them hints at their stability.
More earth pyramids, this time composed of a reddish matrix packed with rocks. These ones were less overgrown, so I assume they are eroding much faster.
I was careful and selective with my souvenirs, but needless to say I came back with a few chunks of Italy to call my own. A piece of Ifinger granite, a garnet, some schist and some mica. Having them is like keeping a portal in my house: I can pick them up and run my fingers over the surface, instantly transporting me back to the mountains. I do wonder what future geologists and archaeologists would make of them if they ever found the remains of my house...

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