We present a new database of >300 layer orientations from sedimentary mounds on Mars (Mount Sharp/Aeolis Mons, plus Nia, Juventae, Ophir, Ceti, Melas, Coprates, and Ganges Mensae). Together, these mounds make up ~ ½ of the total volume of canyon/crater‐hosted sedimentary mounds on Mars. The layer orientations, together with draped landslides, and draping of rocks over differentially eroded paleodomes, 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 model of landscape evolution 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. The model predicts that Mars mound stratigraphy emerges from a drape‐and‐scrape cycle. 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.

Large alluvial fan deposits on Mars record relatively recent habitable surface conditions (≲3.5 Ga, Late Hesperian ‐ Amazonian). We find net sedimentation rate <(4–8) μm/yr in the alluvial fan deposits, using the frequency of craters that are interbedded with alluvial fan deposits as a fluvial‐process chronometer. Considering only the observed interbedded craters sets a lower bound of >20 Myr on the total time interval spanned by alluvial fan aggradation, >103‐fold longer than previous lower limits. A more realistic approach that corrects for craters fully entombed in the fan deposits raises the lower bound to >(100–300) Myr. Several factors not included in our calculations would further increase the lower bound. The lower bound rules out fan formation by a brief climate anomaly. Therefore, during the Late Hesperian ‐ Amazonian on Mars, persistent or repeated processes permitted habitable surface conditions.

Large alluvial fan deposits on Mars record relatively recent habitable surface conditions (≲3.5 Ga, Late Hesperian ‐ Amazonian). We find net sedimentation rate <(4–8) μm/yr in the alluvial fan deposits, using the frequency of craters that are interbedded with alluvial fan deposits as a fluvial‐process chronometer. Considering only the observed interbedded craters sets a lower bound of >20 Myr on the total time interval spanned by alluvial fan aggradation, >103‐fold longer than previous lower limits. A more realistic approach that corrects for craters fully entombed in the fan deposits raises the lower bound to >(100–300) Myr. Several factors not included in our calculations would further increase the lower bound. The lower bound rules out fan formation by a brief climate anomaly. Therefore, during the Late Hesperian ‐ Amazonian on Mars, persistent or repeated processes permitted habitable surface conditions.

Gale crater, the field site for NASA's Mars Science Laboratory Curiosity rover, contains a diverse and extensive record of aeolian deposition and erosion. This study focuses on a series of regularly spaced, curvilinear, and sometimes branching bedrock ridges that occur within the Glen Torridon region on the lower northwest flank of Aeolis Mons, the central mound within Gale crater. During Curiosity's exploration of Glen Torridon between sols ∼2300–3080, the rover drove through this field of ridges, providing the opportunity for in situ observation of these features. This study uses orbiter and rover data to characterize ridge morphology, spatial distribution, compositional and material properties, and association with other aeolian features in the area. Based on these observations, we find that the Glen Torridon ridges are consistent with an origin as wind‐eroded bedrock ridges, carved during the exhumation of Mount Sharp. Erosional features like the Glen Torridon ridges observed elsewhere on Mars, termed periodic bedrock ridges (PBRs), have been interpreted to form transverse to the dominant wind direction. The size and morphology of the Glen Torridon PBRs are consistent with transverse formative winds, but the orientation of nearby aeolian bedforms and bedrock erosional features raise the possibility of PBR formation by a net northeasterly wind regime. Although several formation models for the Glen Torridon PBRs are still under consideration, and questions persist about the nature of PBR‐forming paleowinds, the presence of PBRs at this site provides important constraints on the depositional and erosional history of Gale crater.