Charlevoix
Key facts
- Country
- Canada
- Diameter
- 54 km
- Age
- about 450 million years
- Location
- 47.53° N, 70.30° W
A great half-circle of valleys and hills on the north shore of the St Lawrence River, with the central peak of Mont des Éboulements rising in the middle and towns such as Baie-Saint-Paul and La Malbaie at its edges.
Charlevoix, on the north shore of the St Lawrence River in Quebec, is one of the few large impact craters where many thousands of people live. Its towns, farms and villages sit inside a landscape shaped by an ancient impact, and its central peak rises above the river like a giant's footstool.
The impact. An asteroid perhaps a couple of kilometres across struck here, forming a crater about 54 km wide. For years the impact was dated to about 340 million years ago, but more recent dating of shocked zircon crystals, published in 2019, suggested an older age of about 450 million years, in the Ordovician period. The southern half of the crater lies beneath the St Lawrence River, so on land we see only the northern half, a great semicircle of hills and valleys.
The central peak. At the centre of the structure rises Mont des Éboulements, about 770 m high. It is the eroded central uplift, made of rocks pushed up from deep beneath the crater floor. Around it, a ring-shaped valley marks where the crater floor dropped down. The towns of Baie-Saint-Paul and La Malbaie lie at the edges of the structure, where rivers have carved their way to the St Lawrence.
Discovery. The impact origin of Charlevoix was recognised in the 1960s by the Quebec geologist Jehan Rondot, who found abundant shatter cones and other signs of shock in the rocks. Since then, many studies have mapped the structure and its impact rocks.
An earthquake zone. Charlevoix is one of the most active earthquake regions in eastern Canada. Strong earthquakes have struck the area several times in recorded history. Geologists think the earthquakes are caused mainly by ancient faults along the St Lawrence valley, formed when the continent was stretched hundreds of millions of years ago. The impact crater may have weakened the crust further, making the faults more likely to slip, although the exact link is still being studied.
A cultural landscape. Charlevoix is famous for its beauty, with rolling hills, steep river valleys and views over the wide St Lawrence. It has attracted painters, writers and holidaymakers for well over a century. The region is a UNESCO Biosphere Reserve, recognised for its combination of natural and cultural heritage.
Visiting. Charlevoix is easy to reach by road from Quebec City. Viewpoints around the region give a sense of the crater's shape, especially from high ground looking towards Mont des Éboulements. Local museums and visitor centres explain the impact. Rocks should not be collected without landowner permission.
Why it matters. Charlevoix shows how an ancient impact can shape a landscape where people live and work, and how it may influence earthquake activity long after the event.
Did you know?
Only the northern half of the Charlevoix crater is on land; the southern half lies beneath the St Lawrence River.
Charlevoix is one of the most earthquake-prone areas in eastern Canada.
Recent dating suggests the crater is about 450 million years old, older than once thought.