The northern plains of Mars contain a vast deposit, covering one-sixth of the planet, that apparently resulted in extensive lithospheric deformation. The center of the deposit may be as much as 2-3 km thick. The deposit has lobate margins consistent with the flow of fluidized debris for hundreds to thousands of kilometers derived from highland and high-plains sources. The deposit surface lowers inward by ???900 m in places and is locally bordered by a bulge ???300 m high. Similar deformation accompanied development of Pleistocene ice sheets on Earth. The lack of burial of a large inlier of older terrain and the response time of the mantle to the loading require that the deposit was emplaced in <1000 yr, assuming that the deposit was originally flat. We account for what may have been the largest catastrophic erosional and/or depositional event in solar system history by invoking pore-filling subsurface CO2 as an active agent in the processes of source-rock collapse and debris flow.
Additional publication details
Huge, CO2-charged debris-flow deposits and tectonic sagging in the northern plains of Mars