What characteristic of the water environment is strongly indicated by the presence of Martian clays (phyllosilicates)?

Answer

Formation through prolonged chemical weathering in neutral or slightly alkaline water

Clays form when rock undergoes prolonged chemical weathering in water that is stable and non-acidic, pointing towards conditions closer to those conducive to life.

What characteristic of the water environment is strongly indicated by the presence of Martian clays (phyllosilicates)?
MarsGeologywaterevidencehypothesis