The Charlevoix Astrobleme

Paddle through a cosmic scar

When you arrive in Baie-Saint-Paul, it feels like stepping into a hidden world — a luminous valley cradled between the sea and the mountains. It’s no coincidence. About 450 million years ago, a massive meteorite struck the Earth and forever transformed the Charlevoix landscape.

A cosmic impact — on Earth

A little over 450 million years ago, you would have been paddling through the warm, shallow waters of a disappearing ocean — yes, that’s right! Oceans open (form) and close (vanish) — bordered by a wide chain of towering mountains. These mountains were probably as high as the Himalayas, reaching about 8 kilometers in altitude!

A cosmic impact — in space

Where do meteorites come from? Long before reaching Earth, they were asteroids — fragments of ancient massive celestial bodies orbiting the Sun. And although it may sound incredible, the formation of rocky planets came from the combined effect of gravity and countless collisions between celestial objects of all sizes, a process known as accretion. These collisions were extremely common 4.5 billion years ago and have become much rarer over time. Many large asteroids have long traveled through our Solar System, and some crossed Earth’s orbit — leaving behind visible traces, some of which can still be observed today!

The impactor

To create a complex-type crater, the meteorite (an asteroid that struck the Earth) must have been enormous. Ongoing research aims to determine more precisely the impactor’s origin, age, and composition. Love numbers? Here’s something to satisfy your curiosity while waiting for the latest scientific findings: - Estimated mass: 250 billion tonnes - Diameter: 5.4 km - Speed: 72,000 km/h - Crater diameter: 70 km (now 54 km after erosion) - Energy released: 775 million times that of Hiroshima - Central uplift: Mount des Éboulements

Incredible, right?

Traces of the impact

An explosion of this magnitude doesn’t just leave an enormous scar — it transforms geological matter itself! The energy released by the impact spread as a shock wave through the air, water, and Earth’s crust. The wave was so powerful that it fractured the rock, sometimes giving it a distinct structure called shatter cones — conical striations that distinguish impact rocks from ordinary ones. Other rocks also bear witness to this cosmic event through their formation, composition, and distribution; these are grouped under the name impactites.

A landscape shaped by time

Today, the breathtaking landscapes of Charlevoix reveal what remains of the Ordovician mountains — their very roots! After hundreds of millions of years of erosion by wind, water, and glaciers, the edges of the ancient meteorite impact crater are now much smoother, leaving only a barely perceptible trace: an astrobleme. Still, it’s no small thing — it ranks as the 11th largest in the world and the 3rd most significant in Canada. And the best part? You can paddle right through it.