Quebec has a lot of interesting geology that is easy to visit, the little mountains near Montreal are the remains of volcanoes, Quebec also has, made noticeable through its many hydro electric projects, a massive crater ring lake in its North East.
This stuff looks like grey clay that is super saturated with water, with a more sandy layer on top, from google maps the two farms have an open ditch drain that runs between the properties right around the area of the slide. After it crosses the paved road it empties into a woodland greenspace that angles down towards the bow in the river.
Google map location: https://maps.app.goo.gl/oZmb5qXyt7HPL17j6