The rock of the Canadian Shield sometimes runs dozens of kilometres deep, making this a highly stable geologic zone where earthquakes are rare. In other words, this is excellent soil for constructing underground facilities and safe retaining structures. These tremendous masses of ice also literally pulverized the rock, transforming it into till. Rock outcrops in the territory are covered here and there with lichen, a fascinating transition between mineral and plant life. An alga and a fungus living together in symbiotic association draw sustenance right from the rock and gradually produce a new body, lichen, which is highly resistant to drought, cold and heat.
Caribou eat almost nothing else.
Lichen takes about a hundred years to develop. In other words, the rock here is very old, the vegetation very young. There are few large mammals in the Robert-Bourassa region, apart from black bear. Small furbearers, mainly beaver, are, however, numerous. There are also wolves, lynx, fox, hare, mink and otter.