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I found this old(ish) paper about #JezeroCrater and the delta really educative and accessible even when #IAmNotAGeologistTMBut

Schon et al. "An overfilled lacustrine system and progradational delta in Jezero crater, Mars: Implications for Noachian climate"
researchgate.net/publication/2…

A lot of substance and recognizable features in almost every figure, some examples:

Fig 4. : Topographic profiles from MOLA point data of Jezero crater (top) and a similarly sized fresh crater (bottom) found in Elysium Planitia (8.25 1 N, 125.75 1 E). This comparison shows that Jezero crater (top) has experienced approximately 1-km of infilling compared to the morphologically fresh crater. Lake level is shown at À 2400 m as suggested by the elevation of the outlet.
Fig. 10: Escarpment of the deltaic deposits truncates a scroll bar. The orientation of this meander indicates that the direction of migration was proximal (toward the watershed, away from the escarpment). This orientation requires a more extensive delta in the past.
Fig. 12: Scroll bars. Numerous scroll bars (lateral accretion topography) are observed adjacent to Belva crater on the delta plain and stratigraphically below erosionally-resistant materials interpreted as channel sands. These features (A–H) result from the development of point bars at the inside of distributary channel meander bends. Arrows indicate the direction of channel migration. Unconformities in the scroll bar patterns are common and suggest successive channel migrations.
Fig. 14: Channel deposits. (A) Stratigraphically above the scroll bars and epsilon cross-bedding are elongate erosionally resistant materials interpreted as channel sands. Consistent with the interpretation of a more extensive delta in the past, these channel sands would have been deposits in distributary channels sourcing more distal depocenters, and are high-standing because they are more erosionally resistant than overbank deposits. (B) Channels sands are mapped in green, scroll bars in blue, and craters in purple.
#JezeroCrater #iamnotageologisttmbut

Astro Migration reshared this.

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V Martín
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V Martín
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I still have to fully wrap my head around epsilon cross-bedding and scroll bars, but it's nice to have an explanation for those features on Belva.

(Fig. 13 from the paper and a snaphot from @NeV_T 's gigapan
gigapan.com/gigapans/232283 )

Fig. 13: Deltaic deposit cross-sections. (A) Belva crater provides a cross-sectional view of the deltaic sedimentary materials. The crater is oriented in this view such that north is to the left and basinward toward the top. In the walls of this crater, epsilon cross-bedding, resulting from lateral accretion surfaces within point bars, is observed. (B) Within the crater, three clear examples of epsilon cross-bedding are observed (B,C,D). In these outcrops lateral accretion is observed in both the basinward direction (B, D) as well as laterally (C), consistent with the interpretations of meandering distributaries of a subaerial delta plain environment. Lateral accretion surfaces dip in the direction of channel migration (indicated by arrows). The paleocurrent direction is parallel to the strike of the lateral accretion surfaces.
The features from fig. 13B as seen from the ground by Perseverance

PERSEVERANCE 772-BELVA CRATER

PERSEVERANCE 772-BELVA CRATER © NASA/JPL-Caltech/MSSS/ASU/NeV-T Gigapan - http://www.gigapan.com/gigapans/232283 GIGAmacro - https://viewer.gigamacro.com/view/IeyTy2zVNB5Yio1Q?x1=45873.50&y1=-7431.50&res1=47.78&rot1=0.00 Flickr - https://www.
www.gigapan.com
@NeV_T
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V Martín
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V Martín
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Important to note: it is my understanding that the interpretations of lava flows in this paper as e.g. on fig. 5, may be incorrect, specially in light of what #PerseveranceRover studied at the Máaz- and Séítah formations.
Fig. 5: Lava flooding of the Jezero crater floor in areas of eroded deltaic deposits. Directly basinward of the continuous sedimentary deposits in Jezero, embayment relationships indicate that the delta was larger in the past. In this scene, light-toned sedimentary material (with dunes) has been embayed by an early Amazonian unit interpreted as volcanic. Craters that impacted on the boundary between the competent volcanic material and the weak sedimentary deposit (marked with white arrows) have experienced differential preservation. The previously high-standing deltaic material eroded to approximately its present configuration prior to formation of the volcanic unit.
#perseverancerover
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