ArcTrain Summer School – Day 7: Paddling in a crater

We explored the Uapishka region yesterday during our hike and got a glimpse of the massive meteorite crater from above. Today, we have a chance to get closer. We boarded a ZODIAC boat and a canoe to observe the landscape from the lake which has formed inside the crater. Due to the large scale of the unusual round shape of the rivers going around the central island is best observed from satellites. The whole crater cannot be seen from the water we paddle on but the surrounding mountains are still a breath-taking view.

About 214 million years ago a meteorite hit the region. Flying through the atmosphere, the massive rock (about 5 km in diameter) from outer space heated up and arrived on the planet as a melting and extremely hot body. The impact was so strong that a crater of 100 km in diameter was created, which makes it one of the largest craters in the world. The rocks on the ground instantly turned liquid, forming the crater and a central island. This can be compared to a raindrop falling into a lake that freezes right at that moment (like in the picture below to the right).

Raindrop as analogy to meteorite impact. Source:, last access 2019-09-12, 10 30 pm.
Manicouagan crater from above, Sentinel-2 satellite image.
‘Impactite’ rock. Credit: Dmitrii Murashkin.

The heat released upon impact produces molten lava that includes pieces of rocks creating so-called ‘impactite’ rock formations, shown in the photograph to the left. Those inclusions can contain rocks which have already been at the site, rock materials that could have been brought by the meteorite and rocks that could have occurred in the process of metamorphism (process in which the structure of material is changed due to high temperatures). We explore these rock formations as we climb on a small island that we reach by ZODIAC.

In the 1960’s the region was flooded for the construction of hydroelectric power plants. This submerged a part of the forest growing in the crater. The plants now decay under water releasing mercury. Nowadays it is recommended to eat no more than two fish from the lake within one week. Due to high demand of electricity there are plans to build a new dam and to increase the water level in the lake up to 10 meters. About 50 cabins located around the crater would be affected. At the moment the Innu council blocks the project.

Beaver. Credit: Dmitrii Murashkin.

The awesome day is finished off with a beaver sighting. The unofficial Canadian national animal gives us a full show of protectively swimming around its territory and flapping its tail to scare us away.

Written by Marilena Geng and Dmitrii Murashkin.

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