Be careful in the interpretation
It is also entirely possible that we're seeing a terminal volcanic episode of carbonatite lavas and eruptives, coating the surface some 3.6 billion years ago and that there was NOT a friendly aqueous environment.
The only thing that this find REALLY proves, is that in some areas the carbonates have been protected from those acidic waters that were so prevalent at Meridiani.
Never rush an interpretation. Take time to think of the alternative scenarios. They are many, and some of them are also very interesting, but in different ways...