Pacing Early Mars fluvial activity at Aeolis Dorsa: Implications for   Mars Science Laboratory observations at Gale Crater and Aeolis Mons
  The impactor flux early in Mars history was much higher than today, so sedimentary sequences include many buried craters. In combination with models for the impactor flux, observations of the number of buried craters can constrain sedimentation rates. Using the frequency of crater-river interactions, we find net sedimentation rate \lesssim 20-300 {\mu}m/yr at Aeolis Dorsa. This sets a lower bound of 1-15 Myr on the total interval spanned by fluvial activity around the Noachian-Hesperian transition. We predict that Gale Crater's mound (Aeolis Mons) took at least 10-100 Myr to accumulate, which is testable by the Mars Science Laboratory. 
Edwin S. Kite, Antoine Lucas, Caleb I. Fassett
astro-ph.EP physics.geo-ph