Evolution of major sedimentary mounds on Mars

Edwin S. Kite, Jonathan Sneed, David P. Mayer, Kevin W. Lewis, Timothy I. Michaels, Alicia Hore, Scot C.R. Rafkin
(Submitted on 31 Mar 2017)

We present a new database of >300 layer-orientations from sedimentary mounds on Mars. These layer orientations, together with draped landslides, and draping of rocks over differentially-eroded paleo-domes, indicate that for the stratigraphically-uppermost ∼1 km, the mounds formed by the accretion of draping strata in a mound-shape. The layer-orientation data further suggest that layers lower down in the stratigraphy also formed by the accretion of draping strata in a mound-shape. The data are consistent with terrain-influenced wind erosion, but inconsistent with tilting by flexure, differential compaction over basement, or viscoelastic rebound. We use a simple landscape evolution model to show how the erosion and deposition of mound strata can be modulated by shifts in obliquity. The model is driven by multi-Gyr calculations of Mars’ chaotic obliquity and a parameterization of terrain-influenced wind erosion that is derived from mesoscale modeling. Our results suggest that mound-spanning unconformities with kilometers of relief emerge as the result of chaotic obliquity shifts. Our results support the interpretation that Mars’ rocks record intermittent liquid-water runoff during a >108-yr interval of sedimentary rock emplacement.

Subjects:    Earth and Planetary Astrophysics (astro-ph.EP)
Journal reference:    Journal of Geophysical Research – Planets, 121, 2282
DOI:    10.1002/2016JE005135
Cite as:    arXiv:1703.10997 [astro-ph.EP] (or arXiv:1703.10997v1 [astro-ph.EP] for this version)
Submission history
From: Edwin Kite
[v1] Fri, 31 Mar 2017 17:43:35 GMT (8936kb)
https://arxiv.org/abs/1703.10997