You are crossing the “tufière” marsh which is either watery, or dry.
The water which comes from small surrounding sources flows along the waterproof slopes of the marl surfaces.
On their route, it leaves excess limestone in the form of crusted tufa mixed with peat. This is how the marsh of the tufa slope is created.
We notice especially to the left a small depression, a sort of little cascade, made by the forming tufa.
These original tufa environments often situated within forests are typical of Langres’ plateau. They are generally rare in France and shelter a specific flora, usually protected, for example, marsh epipactis, vivacious swertie or gentiane pneumonanthe.