It often determines the strength of the vegetation and it also plays a role in the construction methods used. Let’s take, for example, the rocks that rise to the surface in several places of the forest.
The elders extracted sandstone that mostly make up part of the stone walls of the buildings today. Larger or smaller craters resulting from these extractions were filled with water to give birth to ponds. The sablon base is used for lime mortar. The clay that makes up the flat tiles comes from nearby tuileries. The height of the oaks shows the deepness of the soil and the straightness of trunks shows that the clay-humus complex provides great fertiliser.
The water in the wells gives the level of the water table surface which is only 5 or 6 m deep.
More generally, we are in the Brie region, land of wheat in the Paris basin. Privileged land where, from year to year, you feel the different shortcomings and climatic conditions less than in other regions of France.
I do not think a soil test is very interesting for our visitors. However I think earth really influences the feeling of things in that kind of place.