Ah yes, Becquerel, noted quite some time back as a remarkable analogue to the always compelling White Rock. But then there are many more similar formations in mid-latitude craters, with a concentration of large ones in Arabia, just north of Meridiani, were a spacecraft roams and takes close up pictures...

The mystery of these layered "white rock" (or "light toned") formations continues, but any discussion of them without reference to discoveries in Meridiani (such as we see in the Universe Today piece) is bizarre. More than likely, the deposits in Meridiani are very similar to if not identical with the deposits in and around the Arabia craters and in Valles Marineris and nearby enclosed canyons. The idea that these deposits result from release of internal fluid -- call it "water" for short, but it was probably a mild-to-strong sulfuric acid solution -- has been around quite a while. Given the remarkable uniformity of the layering, down apparently to very tiny scales, if the Meridiani deposits really are analogous to Becquerel's and others, we're looking at an astonishing record, a historical tale we can't quite decipher, but a story Mars is telling us just the same.

Repeated releases of "water" from the interior, on what appears to be a very regular cycle, leaving a thin crust of precipitate/evaporate each time -- each 12ft thick layer (if analogous to Meridiani) is probably composed of hundreds or even thousands of much thinner layers -- with a much "stronger" deposit every 10 or so cycles between the 12ft layers...

What could it mean?

Why in only certain locations, mostly in a swath relatively near the equator that extends from Valles Marineris eastward, petering out somewhat east of Meridiani itself.

Are the deposits really "rock" or are they salts/sulfates such as those found in Meridiani?

And these light toned deposits are always accompanied by what's called "dark sand" -- but is it actually more of the "blueberries" found so extensively in Meridiani and Gustav? Blueberries that some have tried to argue result from biological processes (without being able to test or prove the case, of course).

Very interesting indeed...