The Tour de France rocks: A fascinating look at the geology of Le Tour

Love the mountains of the world's biggest bike race? Learn all about them (and much more) with GeoTdF.

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More than any other bike race on the planet, the Tour de France is an event that transcends cycling. Every July, millions around the world tune in to watch the world’s best riders duke it out, but millions more watch to marvel at the French countryside and maybe even plan their next holiday.

If that’s you; if you love marvelling at the towering vistas of the Alps and Pyrenees, or if you’re interested in why France looks the way it does, you’ll want to check out

The site is a collaboration between dozens of geoscientists around the world designed to explain the geology of the regions that the men’s and women’s Tours de France pass through. Here’s how one of GeoTdF’s founders explained the origins of the project:

Geoscientists tend to love the outdoors, and are a talkative bunch who can’t stop explaining about their rocks, fossils, landscapes, and natural processes, and the field expeditions they undertook.

At some point I realized that viewers of live coverages of cycling races like the
Tour de France watch hours and hours of geological excursions. Surely, we couldn’t let the opportunity pass to geo-monologue! And these races are covered by commentators that explain just about everything that passes the camera. All we had to do is help the commentators to explain a few things about the landscape and underlying hidden treasures.

As it turns out, there are quite a few geoscientists who love cycling and watching the race, and quite a few cyclists with a keen interest in the environment. GeoTdF was born.

An example of what you can find on GeoTdF. This is for stage 5 of the Tour de France Femmes.

One of the geologists behind the project, Dutch researcher Douwe J.J. van Hinsbergen, wrote about the geology of last year’s Tour de France but this year’s offering is bigger and better.

There are posts up on the site already for all 21 stages of the men’s race, and likewise for all eight stages of the women’s race. Each post explains the geological significance of the region the riders are passes through on a given day.

The posts are short and digestible, but full of maps and diagrams to help illustrate how the landscape of modern day France came to be. You can learn how the mountain ranges formed, why some inland sections of the route used to be underwater, what sort of rocks are used for the famous cobblestone roads near Roubaix, and much, much more.

So if you’re watching the Tour over the next few weeks and you’re keen to learn more about the theatre in which the race is contested, be sure to give GeoTdF a look.

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