I was just noticing this recurring theme in some of the images in the latest MRO release:

Layering In Exhumed Crater at Meridiani.

Mawrth Vallis layered deposits.

and repeatedly something like

Exposure of Polar Layered Deposits.

These images seem to be telling us that processes on Mars are slow and lead to relatively undisturbed layers. Perhaps a discussion of those layers and what they are telling us about the geological history of Mars is in order.

Steve

That's a good observation. For me it is reassuring to discover that layering processes operate on yet another celestial body. If that were not the case, one of the basic premises of geology would be turned on its ear, as they say.