1. Variety of construction rocks

The natural materials that make up our subsoil are highly diverse, ranging from hard, compact rocks (such as granite or marble limestone) to loose, non-cohesive rocks (such as gypsum or sand). Since the dawn of history, all these materials have been used by mankind to build homes and monuments, or to develop and shape the environment. Virtually every type of rock or geological formation has been used.

• Three types of training can be distinguished:

  • the soil, which corresponds to what we generally call the earth. It is the result of the alteration of the subsoil's parent rock in contact with the atmosphere (freeze-thaw cycles, for example) and the biosphere (action of animals, plants, micro-organisms and man);

  • two types of formation corresponding to the subsoil...