Cycling enthusiasts are already digging through the route of the Tour de France and Tour de France Femmes to see which obstacles will be decisive for the 2024 winners. But at the same time, a team of geologists is digging deeper, to tell the stories of Earth’s history that led to those obstacles through blogs and television clips: the enthusiasts of the Geology of the Tour de France team, who developed the web page, and a suite of related social media channels.

For nearly a month each summer, 20 million cycling enthusiasts (including me) watch the live stages of the Tour and a multitude of them will hear or read about it in newspapers, magazines, podcasts, and blogs. Viewers are watching for hours on end in anticipation of the action that will end every stage, but for most of the time, 150 riders are chasing 5 others in a temporary status quo. And that time is filled by TV commentators and analysts explaining everything about almost everything you can see on screen.

Organizations of cycling races therefore provide the commentators with a ‘lonely planet’-style route book with information about castles, cities, or individuals. And then it struck me: we are not only watching potential holiday destinations, but also geological excursions! All we must do is provide the commentators with geo-information. And the Geology of the Tour de France initiative was born.

An unidentified rider pauses among the salt-flat sediments at Col de la Croix, having recently climbed up and over the geological remains of the Briançonnais microcontinent and the Valais and Alpine Tethys oceans. Photo: Peter C. Lippert, Department of Geology & Geophysics, University of Utah, USA

Since 2022, dozens of geoscientists and web developers wrote about the geology along Tour de France stages and also other major cycling classics and tours. Since 2023, Eurosport cycling commentator and journalist José Been joined the Geo-Sports team as blog editor, and as ‘de-nerdifier’, helping to make the geo-stories understandable for a wide cycling audience.

Geo-Sports presenter Douwe van Hinsbergen and producer Mark Carpenter in the Alps.

The blogs are published in 9 languages (English, French, German, Spanish, Italian, Danish, Slovenian, Norwegian, and Dutch). Each blog explains a geological phenomenon or process whose signatures are visible along the stage route, and sometimes the stories of the scientists who recognized them. A myriad of topics pass, from the extinction of the dinosaurs to the subduction zones that made the Alps, from the limestone caves of southern France to the volcanic origin of the cobbles of Roubaix, and from the drying of the Mediterranean Sea to the traces of meteorite impacts. Each blog is a 5-minute read, but if you read them every day, you end up with an extended geology class.

Geo-Sports presenter Marjolein Naudé (Utrecht University) explaining the formation of the Pyrenees.

The Geo-Sports project is a knife that cuts both ways. First, it is a medium to playfully educate a wide audience that is brought together around a sports event, not science. But this audience is hungry for knowledge, and we provide them and the journalists that service them with information about the natural world, its hazards, its resources, and the effects that using these resources have on the natural world.

These are the big issues of our time and the Geo-Sports project provides scientists with a platform to bring knowledge and awareness about processes that impact our society to a wide public, from landslides and earthquakes to the finding of critical metals that we need for the green energy revolution. And the public can respond and ask questions through Twitter, Instagram, Bluesky, Facebook, Tiktok, Mastodon, and Youtube.

Youtube video: ‘The Alps are made of cheese’.

“But the project also has scientific benefits. It provides the wide geoscience community with a platform to showcase its findings and importance, and community members share their knowledge and insight freely and enthusiastically. For me personally, this is why I like the project so much.”

But the project also has scientific benefits. It provides the wide geoscience community with a platform to showcase its findings and importance, and community members share their knowledge and insight freely and enthusiastically. For me personally, this is why I like the project so much. As scientists are always trying to find where we are wrong, for that is how we learn and advance. As a result, scientists tend to scrutinize themselves and each other, through peer review, discussion, debates – the criticism is vocal, the appreciation silent. But that also wears me down at times. The sense of community and enthusiasm around the Geo-Sports project is a nice change. So if you have something to tell or ask, join! And we are not restricted to the Tour de France, cycling and geology are year-round, from Hainan to Argentina, from Cameroon to northern Norway, from Australia to Canada – there’s so much to tell.

At the same time, letting something as random as cycling routes determine the order in which you read up on geology turns out to be an idea and knowledge generator. Natural scientists tend to choose the boundaries of their study areas based on interpreted system boundaries and divide themselves into smaller and more specialized communities in an endless effort to learn more about less. Cycling route designers provide us with a way out, literally. No geologist would read up on a region along such a non-organized and random way as a stage route and doing so is eye-opening. Many of the chance observations along cycling tours connect pieces of knowledge, and some of them challenge systems that I thought I understood. Scientific discovery rarely starts with ‘Euraka’, but normally with ‘hey, that’s funny’. Whether the GeoTdF project will lead to scientific discovery remains to be seen, but fun, it certainly is.

Douwe is a geologist. He works as Professor of Global Tectonics and Paleogeography at Utrecht University. He investigates the plates, oceans, and continents that were lost to subduction. For this, he uses geological remains of these lost plates: rocks that are found in mountain belts all over the world, and subducted plates that can be seen in cat-scans of the Earth’s interior. Since 2021, he explains the geology of pro-cycling races, including but not restricted to the Tour de France.​

Contributor: Douwe van Hinsbergen

Utrecht University, the Netherlands

Disclaimer: This article expresses the personal opinions of the author. These opinions may not reflect the official position of the European Federation of Geologists (EFG).