Mars

Mars’ Young Sedimentary Rocks: Early Thinning, Late Persistence, Diachronous Boundaries, And A Regional Dichotomy

By Keith Cowing
Status Report
astro-ph.EP
March 10, 2025
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Mars’ Young Sedimentary Rocks: Early Thinning, Late Persistence, Diachronous Boundaries, And A Regional Dichotomy
Macrostratigraphy of Mars 3.5 Ga to present. Deposit columns and interpreted stratigraphic correlations organized by relative age and longitude. Stratigraphic correlations are marked by arrows and lines and by the colored masks. We find that Valles Marineris and Arabia Terra sedimentary rocks evolved asynchronously despite the similarities in stratigraphy. In contrast, deposits of the Eastern and Central Medusae Fossae Formation, AeolisZephyria Planum, and Gale crater are hypothesized to be correlative [25], which would span roughly 120◦ in longitude around the planet. Alternatively, Gale crater could have evolved asynchronously from the rest of the Medusae Fossae Formation, perhaps via atmospheric teleconnections to Arabia Terra or Valles Marineris. The bars on the right side of the figure display the interpreted changing controls (cementation potential and atmosphere) and the resulting observable characteristic (layer thickness). Layer thickness peaks during the deposition of rhythmites in Arabia Terra, and sulfates at the Mid-Latitudes and Gale- in our interpretation, this is after the atmosphere has thinned and before significant loss of liquid water has occurred. — astro-ph.EP

Mars’ sedimentary rocks record Gyrs of environmental change. New data enable the first global analysis of paleo-environment relevant physical properties of these rocks, including layer thickness and accumulation rate.

We find that layer thicknesses of post-3.5 Ga sedimentary rocks across the Martian surface show coherent variations at ~1000 km-scale that are inconsistent with simple volcanic and climatic hypotheses for formation, which are consistent with global compositional homogeneity at orbital scales.

These data, in combination with new analyses of outcrop age and total rock volume demonstrate a global decrease in layer thickness that predates the eventual drop off in preserved sedimentary rock volume per Myr.

The new constraints confirm a diachronous transition in Mars’ global sedimentary rock record while also highlighting a regional dichotomy in young sedimentary rock deposits that has not been quantified before.
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)

Madison L. Turner, Sabrina Y. Khan, Kevin W. Lewis, Axel Noblet, Edwin S. Kite

Cite as: arXiv:2503.01047 [astro-ph.EP] (or arXiv:2503.01047v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2503.01047
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Submission history
From: Madison Turner
[v1] Sun, 2 Mar 2025 22:36:26 UTC (6,150 KB)
https://arxiv.org/abs/2503.01047
Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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