Ancient streambed on Mars? What do you think?

BBC news have recently published an article describing some sedimentary structures that Curiosity Rover has encountered.

The images in the article are of a conglomerate named “Hottah”  (named by scientists at Nasa’s Jet Propulsion Laboratory), interpreted as a fluvial (?) deposit.

The photograph appears to show a poorly-sorted, angular assemblage of clasts.  Could this be evidence of rivers on Mars?