  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.

Earth and Planetary Astrophysics;Geophysics