Not uniferm, but certainly widespread
Satellite imagery and IR spectrometry has shown planet-wide long-term arid, saline, and acid conditions.
To find life - as we know it, Jim - we need to find an "oasis" of difference in the sea of acid salt. That's the challenge.
Repeated shouts that "this" or "that" is evidence for liquid water and hence of life on Mars have consistently been proven to be misunderstandings, exaggerations, or even deliberate falsehoods at times.
It is important to retain a rational, cautious, and dispassionate approach to exploring the history of fluids on mars, otherwise the listener/reader/taxpayer will become fatigued by all these cries of "Wolf"...