Shanan E Peters , David B Rowley 

Determining the timescale over which continental surface elevation (hypsometry) evolves is difficult because it reflects a combination of isostasy and dynamic topography operating in concert with erosion and deposition. Here, we use 252 million year old and younger shallow marine sediments exposed at the surface as tracers of net change in continental surface elevation over time. In aggregate, we find that the elevations of Triassic and younger surface-exposed shallow marine sediments closely mirror global continental hypsometry. However, dispersion in the elevations of marine sediments increases with increasing depositional age away from a constant modal elevation of ~0 m. This empirical age-elevation relationship is consistent with the expectations of a diffusion model, wherein shallow marine sediments are continually deposited near 0 m in the submerged and initially subsiding regions of the continents and then undergo vertical displacements down and up with a constant stochastic distribution of rates. When such a model is tuned to empirical age-elevation data, an asymptotically-stable distribution of surface elevations congruent with observed continental hypsometry emerges on a timescale of 10^7-10^8 years.