Evolution of major sedimentary mounds on Mars

Status Report From: e-Print archive
Posted: Monday, April 3, 2017

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)

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