[2] Only part of the impact structure is exposed at the surface, the rest lying beneath the Saint Lawrence River.

The Mont des Éboulements, situated in the exact centre of the impact structure, is interpreted as the central uplift, a consequence of elastic rebound.

[3] The impact structure is classified as a multi-ringed basin with a central uplift.

Other evidence for impact includes planar deformation features (PDFs) in quartz and feldspar grains.

In contrast to the surrounding craggy Laurentian Mountains, the impact structure is relatively smooth and flat, which has facilitated human settlement.