Switzerland: An Alpine Adventure

In late July 2022, we ran our geology trip to the Alps for the first time. As well as the being inaugural running of the trip, we were also delighted to welcome along Dr David Buchs, Senior Lecturer in Geology at Cardiff University, for the first time as co-leader of the tour.

GeoWorld Travel’s ‘Switzerland: An Alpine Adventure’ route map
Day 1: Friday 29th July

Our group all met up in Geneva on the first evening of the tour. All of the group members came from the UK, although co-leader David and one of the guests were born, and grew up, in Switzerland! Having all met on Zoom the previous week, there was just a brief welcome meeting at the hotel before heading out for our first meal together and a chance to chat about the adventure ahead.

Day 2: Saturday 30th July

Setting off from Geneva, we headed up towards the city of Neuchâtel. Our first stop was in the Jura Mountains at a spectacular site called Creux du Van. It is, of course, the Jura Mountains which lend their name to the Jurassic period. At this first stop, we stood on the edge of a magnificent amphitheatre with 200m cliffs made of Jurassic sediments, perhaps the best place to see Jurassic sediments in their type area. The amphitheatre effect has been caused because the Jura Mountains are folded and a fault also exists that rivers eroded and, later, glacial ice eroded, carving our this spectacular feature. Whilst at Creux du Van we took a short hike up to a viewpoint where we were able to look out towards the Alps on the horizon. It was a little hazy, but we could still make them out, as well as seeing Lake Geneva and the Molasse basin, which lies between the Jura Mountains and the Alps. We discussed how we can tell the age of the Jura Mountains, as the Molasse sediments have been dated as miocene, based on the fossils contained in them, and these sediments have only been deposited due to the Jura Mountains being pushed up. Our lunch stop for the day was at a beautiful farm where we enjoyed an authentic Swiss lunch, against a backdrop of a beautiful view over Lake Geneva towards the Alps, complete with cows with bells around their necks – a wonderfully Swiss scene!

After lunch, we headed to the village of Valangin, near Neuchâtel. The village lends its name to the Valanginian stage of the Early Cretaceous. We parked at the castle in Valangin, which is actually built on rock of Hauterivian age, which is another stage of the Early Cretaceous named after the Neuchâtel area. Our next stop nearby was a huge, impressive glacial erratic called Pierre-à-Bot. This enormous rock, which is made of granite, was carried on glaciers in the Ice Age from the Mont Blanc area, approximately 130km away, and deposited in a forest. This glacial erratic is particularly famous because Switzerland’s most famous geologist, Louis Agassiz, used the presence of this erratic to argue the case that the planet had experienced a whole series of Ice Ages and interglacials. Continuing on from Pierre-à-Bot, we arrived in the city of Neuchâtel. Having checked into our hotel, David then led our group on a walk around his hometown! Our walk took in a stop at the Natural History Museum, where we saw a portrait of Louis Agassiz, followed by a trip to the main shopping area – where we examined the paving stones! The reason these are so interesting is that they are made of rounded cobbles left by the glaciers, which contained different blocks from all different parts of Switzerland, including limestones, sandstones, granite, gabbros and even serpentinite. Serpentinite is rock from the earth’s mantle which has been hydrothermally altered and which resembles snakeskin; this would have come from the area around the Matterhorn, which we visit later in the trip. Finally, we climbed up to reach the magnificent church in Neuchâtel. This is built from the attractive Hauterivian limestone and its location afforded magnificent views over the city – a fabulous way to end our first full touring day.

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Day 3: Sunday 31st July

Today’s itinerary took us away from the Jura Mountains and out towards the Alps. On the way from Neuchâtel to our first stop, we passed the capital city of Switzerland, Bern. We had planned to visit St Beatus Caves, but a delay in the journey meant that we were only able to view the site from the exterior. We were still able to look up and study the magnificent, huge cliff made from Lower Cretaceous age limestones within which the cave is also formed. This Lower Cretaceous limestone formed on the European continental margin. This cliff would have been formed by glacial action as a glacier passed by. We continued our journey into the Alps, reaching our destination – Grindelwald. At Grindelwald, we got on the Eiger Express, an incredible cable car which is only a few years old and takes you on an awe-inspiring journey, zooming past the north face of the Eiger. It took us up to a place called Eigergletscher, where we got out of the cable car and into a train.

The train passed through a tunnel and suddenly we were ‘on top of the world’ – well, it certainly felt like it! We alighted at the highest train station in Europe and everything around us was snow-covered. It was incredible to think that in less than an hour, we had travelled up to such altitude. When we left Grindelwald it was 25°C, but up here, it was just 5°C, but with strong sun. This was the start of the Aletsch Glacier which is a UNESCO Global World Heritage Site and there is a wonderful geological story to be told. We were looking at the front of a nappe where granitic basement rock of Variscan age had been thrust over Jurassic sediments. From the viewing platform it was possible to see the contact very clearly – an incredible sight. We also had a pleasant walk in the snow and ice before heading back to the train station. Our route back to the station took us through a fantastic man-made tunnel which has been carved through the glacial ice. We got on the train for the descent, marvelling at what a wonderful experience it had been to be on top of the Alps in the Jungfrau-Aletsch UNESCO World Heritage Site. We arrived back in Grindelwald and then made our way to our overnight stop in Interlaken. Having arrived at our hotel in Interlaken, we then enjoyed a lovely Italian meal and reflected on all of the highlights of a truly breath-taking day.

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Day 4: Monday 1st August

Our first stop of today was in the beautiful historic city of Lucerne. Having passed through the centre of the city and seen its historic bridge, we stopped on the shore of Lake Lucerne to learn more about Switzerland’s tectonic structure. From the viewpoint we stopped at, we were able to see that we were standing on rocks which were deposited in the Molasse Basin. There would have been a thrust fault in front of us, underneath the lake surface, and we could see mountains close by, including Mount Pilatus which is made of Jurassic age sediments, part of a nappe called the Helvetic nappe. Further back behind this mountain were other mountains, such as Stanserhorn, made from rocks of another nappe which had been thrust over the whole area but glacial erosion had left these rocks isolated from others of that same nappe. It was the action of the various faults combined with glacial erosion that made the beautiful shape of Lake Lucerne. Fantastic scenery and a very interesting geological story.

After this, we continued on, entering the UNESCO World Heritage Site Tectonic Area Sardona, a designation awarded to the area due to its geology. It was here that the first nappe was ever identified. A nappe is where a sheet of rock has slid over neighbouring rock and it is a key part of the mountain building process. Our destination was Lochsite and a location where we could literally touch the place where Triassic rock, which had been transported from over 100km away, was lying over the top of much younger, Eocene rock. This thrust fault was identified in a very similar period as the Moine Thrust in Scotland, making these both the earliest thrust faults to be identified in the world. Having enjoyed our picnic lunch at this most fascinating of sites, we moved on to another location within the World Heritage Site, the village of Elm.

At Elm, we took a cable car up the mountain to Tschinglenalp where we had another wonderful view of the Glarus Thrust. We were also able to see another world famous sight here – a hole in the cliff face, called Martin’s Hole. Some of the group stayed around the cable car and enjoyed the cafe and the views, while others took a longer hike up to a location called Firstboden, where there are magnificent views of the thrust fault. Up at Firstboden, it really gave a sense of the whole area in 3D – we could not only see the fault in the cliff in front of us, but also stretching further away into the background. The top of the cliff in front of us was Triassic age rock and then there was a clear colour change, with a paler Cretaceous rock, within which was the hole. This hole is created by a fault cutting through and the base of the hole was actually made of some of this younger Flysch rock which had been entrained into the Cretaceous rock in the whole process of thrusting. Below all of this was more Flysch rock. After taking in these wonderful sites, we took the cable car back down the mountain and headed to our hotel for the night. The hotel was situated next to a beautiful lake, towering above which were enormous Jurassic limestone cliffs, making the site look very similar to the Canadian Rockies. Our day of spectacular geology finished with some spectacular weather – we had a much-needed thunderstorm with lightning, as it had been a very hot day!

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Day 5: Tuesday 2nd August

Today’s itinerary was a real tale of high mountain passes, glaciers and stunning views. We left the Glarus area, taking the Klausen Pass with its numerous hairpin bends climbing up and up. At the summit, we were rewarded with absolutely stunning views, so we stayed here for a while to really take it all in. From a geological perspective, these views were fascinating as we could see Triassic aged rocks which were overlain by lower Jurassic aged rocks. Our journey then took us on the Gotthard Pass, a pass which played a very important role in Switzerland’s history, allowing goods to be transported from Germany through Switzerland all the way down to Italy. We paused our journey here to see the entrance to a railway tunnel cutting through the mountains. Moving on, we travelled on the Furka Pass, another pass with plenty of hairpins climbing and descending the mountain side, finally reaching the Rhône Glacier. The glacier is spectacular, but also tells a rather sad story of glacial retreat. It is possible to see where the glacier had been just 50 years ago, but has since retreated significantly leaving a glacial lagoon with a few icebergs in it. Also visible is beautifully polished granite with striations which the retreating ice had revealed. These granites are important to the geological story as they are the basement rock of the European continent. Also at the site there is a tunnel which has been carved into the glacier. We were able to walk through the tunnel, seeing all the air bubbles trapped in the ice, formed as the snow had fallen, been compressed and turned into ice. There were also rock fragments trapped, entrained within the ice, illustrating really well how glaciers can transport rocks both within and above the ice.

After lunch, we left the Rhône Glacier and headed for Fiesch. On arrival, we got out of the vehicles and into a cable car. We took two different cable cars to reach a place called Eggishorn, back in the Jungfrau-Altesch World Heritage Site. In fact, we could see the Altesch Glacier from Eggishorn coming down in a sweeping curve, and we were at the level of the middle of the glacier. Back on day three, we had been at the Jungfraujoch at the top of the Aletsch Glacier, and it was just possible to make out the Jungfraujoch in the far distance. We were lucky enough to have fantastic weather and it was great to see the glacier snaking down the mountain with its many crevasses and the black stripes running down the length of it, which are medial moraines where different ice streams have joined the glacier. We took the two cable cars back down the mountain to Fiesch, where we got back into the vehicles to head to Täsch, near Zermatt, where we were spending the next two nights.

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Day 6: Wednesday 3rd August

Today was a day of magnificent geology under the gaze of the mighty Matterhorn mountain. We started in the village of Täsch, taking the short walk from our hotel to the train station where we boarded a train for the 15-minute journey to Zermatt, which is a car-free town. We walked through the town from the train station to the cable car station, picking up a picnic lunch on our way and stopping outside the local museum to look at a spectacular outcrop of eclogite. There were round circles in the surface of the eclogite which were originally pillow basalts (formed on the spreading ridge of an ocean) that were then taken down to enormous depths in the subduction zone, only later to be thrust back up to the surface during the formation of the Alps. Our first cable car journey was up to Trockener Steg, where we changed on to another cable car up to Klein Matterhorn. This is the highest cable car anywhere in Europe, climbing to a staggering 3,880m! On the ride up, our cable car passed right over incredible glaciers and we were able to look down and see the crevasses, the ogives, the lateral moraines and the medial moraines. We arrived on Klein Matterhorn to be met with absolutely stunning views. Despite the name, the Klein Matterhorn is almost as high as the Matterhorn itself. All around us was glaciated, but the glaciers were clearly in a poor state with a lot of melt occurring in these current very hot conditions. From the high point, we were able to look across at the Matterhorn and see how the upper part of the mountain is formed from rock which derives from the African continental crust. Beneath this, at the base of the mountain, were rocks which were formed in an ocean and these rocks are ophiolitic rocks (formed in an ocean basin, dragged down a subduction zone and brought back to the surface in the continental collision). So what we were basically seeing in the Matterhorn is the plate boundary between Africa (top) and Europe (bottom) with oceanic crust squeezed in between. A really breath-taking view!

We then took the cable car back down to Trockener Steg where some of the group set off on a glacier walk while some others return down to Zermatt to enjoy some free time in the town. On the glacier walk, we were able to walk right through these beautiful ophiolitic rocks, which derived in the mantle and have since been changed into serpentine due to hydrothermal reactions. We also saw many other beautiful rocks including metagabbros and, perhaps the most exciting rock we saw, eclogite, which has a green mineral in it called omphacite and lovely red garnets. This forms when basaltic or oceanic crust rocks gets taken down a subduction zone and will only form in high pressure, low temperature conditions. It was great to be able to walk through all the different rock types and to be so close to the retreating glaciers, all in the shadow of the mighty Matterhorn mountain. We returned to the cable car station and descended to Zermatt, where we caught a train back to our hotel in Täsch.

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Day 7: Thursday 4th August

Leaving the Matertal Valley in the morning, we travelled back down to the Rhône Valley, a huge valley that passes through the Alps and exists because it is the boundary between the two main nappes of the Swiss Alps. We then travelled into the valley adjacent to the Matertal Valley, the Hérens Valley. Our first stop of the day was the Pyramids of Euseigne, which are magnificent hoodoos – boulders perched on top of cones made of glacial moraine. What seems to have happened is that there was a large boulder protecting the smaller boulders and all the meltwater ran around these. Over time this left a ridge of moraine with these boulders perched on top, then rain getting in between them eroded it all away and all that is left is these boulders perched on top of these cones of moraine material. After seeing these amazing features, we moved on up the Hérens Valley, reaching a beautiful village called Les Haudères, where the Geology and Glaciology Centre opened specially for our group. We had a look around the exhibits, enjoyed the excellent display on the geology of the area and watched an interesting video on glacial features and processes.

Continuing up the valley, we stopped at Seppec to see some greenschist rock. These rocks would have been lavas which were erupting out onto the sea floor in the spreading ocean, the Tephus Ocean, and have now been metamorphosed into greenschist facies rock. Having had our lunch here, we then carried on, passing through a tunnel which, although it was concreted over, is actually the suture where the rock from the African crust is thrust over the top of this oceanic crust. When we emerged from the other end of the tunnel, you could say we were in Africa! All around us was gneiss rock, a metamorphic rock which had actually been part of the African continent, and when the Apulian Plate (as the piece which broke off Africa when it collided is called) collided with Europe to create the Alps, this rock had slid over the top of the oceanic and European crust rocks. We then parked at a place called Ferpècle where we had a great walk amongst these rocks of African origin, up into a very glaciated area where we could see moraines, glacial meltwater thundering down (as the ice was melting at such a rapid rate) and we had views of the mountain Dent Blanche, which is like the Matterhorn, in that it is made of rocks that were originally part of Africa. Returning to our vehicles, we headed back down the valley, stopping in Les Haudères again for some refreshments, before heading on to the beautiful historic town of Sion where we were spending the next two nights.

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Day 8: Friday 5th August

We left the town of Sion this morning for a day trip and headed up a very high, twisty road directly to the north of Sion, up to the Sanetsch Pass. This took us into the Helvetic nappes and gave us the opportunity to see a very interesting sedimentological sequence. There was a Cretaceous age limestone that formed in marine conditions, but in the Palaeogene this rock would have been at the surface and there would have been trees growing on it at this time. Close to where we were, but not at the point we stopped at, fossil soils from that time have been found. What we did see though were Eocene limestones deposited in the cracks in this Cretaceous limestone, which contained a foram called nummulites. Also deposited on top of that, we saw early Oligocene aged marls and Oligocene aged turbidites, showing how water conditions there got deeper. We walked around on this limestone which consisted of a limestone pavement with clints and grykes and swallow holes, along with many beautiful flowers.

Driving back along the Sanetsch Pass with all of its hairpin bends, we got back to Sion and then we headed a short distance east to a village called St Leonard, where we visited the largest underground lake in Europe. Here we saw rocks which were in the Penninic nappe; marble, gypsum and shale, all together in sequence. However, the gypsum, which is an evaporite, had been dissolved out by water, leaving this cave. We were taken in a boat through the cave on an underground tour of this subterranean lake. After the boat tour, we headed back to Sion mid-afternoon where we had some free time. People were able to explore the wonderful church, the Valère Basilica, and the castle, Château de Tourbillon. These two historic buildings, dating back to the Middle Ages, both stand on blocks of quartzite rock which may have fallen down the face of a nappe as a frosting was occurring in the initial stages of the building of the Alps and they now exist as huge boulders which the castle and the church are built on. There was a very good museum here which explained about the history of this part of Switzerland, which is called Valaise; Sion is the capital of Valaise.

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Day 9: Saturday 6th August

We left the historic town of Sion this morning for our final full day of the tour. We travelled west along the Rhône valley which forms the approximate contact between the Helvetic Nappe (rocks that were once part of the European foreland) and the Penninic Nappe (rocks that were once part of the Valais Basin, Briançonnais micro continent & Tethys Ocean). At Martigny, the Rhône makes an abrupt right angle turn north, but we continued west and started to ascend part of the Mont Blanc massif on the Swiss/French border to reach the Émosson Dam. Here we had spectacular views of Mont Blanc in France. We had an excellent guided tour, exclusively for our group, which detailed how the dam was built and taught us about the surrounding geology, as well as giving us a chance to go inside the dam itself. The Émosson Dam is built on Variscan-aged granites of the Aarmassif which are analogous with the Mont Blanc massif. Just to the north of the dam, Triassic and Jurassic sedimentary rocks of the Helvetic Nappe outcrop and in these Triassic rocks, archosaur tracks have been found, which were once thought to be dinosaur tracks. The dam itself was built to provide hydroelectric power for the Swiss railways and was opened in 1972. The water is taken from rivers and glaciers by an ingenious network of pipes via a gravity-fed system. It is the third highest dam in Switzerland and it only lies entirely in Switzerland because a border change was made in the 1960s during the planning phase. After having had lunch at the dam, we then descended to the base of the Mont Blanc massif and visited the Gorges du Trient. This spectacular gorge, which is 463m high at its maximum, was created by a subglacial river in the last ice age and cuts down into rock of the Mont Blanc massif. The gorge was further enlarged by glacial melt at the end of the ice age. Today, the gorge only contains a very small stream, because its water is being diverted into the Émosson reservoir.

Our next stop was a roadside stop where we had a view of the Morcles nappe. These spectacularly folded rocks are the leading edge of a Helvetic nappe. We then followed the River Rhône north until it reached Lake Geneva. This massive lake is one of the largest lakes in western Europe with a maximum depth of 310m and a maximum length of 73km. On the shores of Lake Geneva, we drove past the beautiful Château de Chillon, reaching the Lavaux, Vineyard Terraces World Heritage Site. Our first stop in this area was to look at an outcrop of the Molasse, and the second stop was for a panoramic view of the vineyard terraces and Lake Geneva. We then enjoyed our final trip dinner together in a traditional restaurant and winery, before returning to the city of Geneva for our final night.

Please click on images to enlarge and to read the captions

Day 10: Sunday 7th August

Our group dispersed this morning, with some people returning home and others extending their stay in this wonderful country. We have been treated to some truly spectacular geology on a grand scale and the trip has given a real insight into the very complex geology of Switzerland. Our thanks to all of the participants and, in particular, to David Buchs for his excellent co-leadership of the tour – a very welcome addition to the team!

We will be returning to Switzerland again in the future – please check our website for the latest dates/availability: https://www.geoworldtravel.com/Switzerland.php

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