Challenges in crater chronology on Mars as reflected in Jezero crater

Rubanenko, Lior; Powell, Tyler M.; Williams, J. P.; Daubar, I. J.; Edgett, K. S.

doi:10.1016/b978-0-12-820245-6.00005-7

Cited by 5 publications

(10 citation statements)

References 85 publications

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“…Similar observations and conclusions are presented in Rubanenko et al. (2021). The presence of remnants around the main fan (Stack et al., 2020) and the exposure of inverted channel bars also argue for an intense erosion of the main delta fan since emplacement.…”

Section: Review Of Crater‐based Age Determination Of the Dark Crater ...supporting

confidence: 92%

“…The CSFD described in Mangold et al has a slope lower than those of the isochrons, which suggests that the delta fan was emplaced before 3.5 Ga and has been continuously affected by resurfacing processes since then. Similar observations and conclusions are presented in Rubanenko et al (2021). The presence of remnants around the main fan (Stack et al, 2020) and the exposure of inverted channel bars also argue for an intense erosion of the main delta fan since emplacement.…”

Section: Review Of Crater-based Age Determination Of the Dark Crater ...supporting

confidence: 83%

“…The dark floor unit thickness has been determined at 10 to 30 m (Schon et al., 2012; Shahrzad et al., 2019). It means that according to a crater depth/diameter of about 0.2, from 200 to 300 m in diameter (Rubanenko et al., 2021), the craters start to impact the underlying unit. Also, in the case of emplacement of the dark floor unit on a cratered paleo‐surface, it means that the unit would not have completely buried craters larger than 200–300 m. In such a scenario, large craters may be older than the floor unit.…”

Section: Methodsmentioning

confidence: 99%

“…No inner geological boundaries are observed to confirm this hypothesis from orbit. On the contrary, several independent studies (orbital data‐based) of the dark floor unit (Goudge et al., 2012; Rubanenko et al., 2021; Shahrzad et al., 2019) have mapped this unit as a single unit with a very well defined external boundary.…”

Section: Orbital Data and In Situ Analysismentioning

confidence: 99%

“…The stratigraphic relationship between the dark cratered floor unit and the delta is not so clear from orbital data analysis. As the crater floor is the only major crater‐retaining surface within Jezero, its crater density has been investigated by several independent studies and the ages returned range from 1.4 to 3.5 Ga, that is, from Amazonian to Hesperian (Goudge et al., 2012; Marchi, 2021; Rubanenko et al., 2021; Schon et al., 2012; Shahrzad et al., 2019; Warner et al., 2020). The relatively small areal extent of the unit implies large uncertainties on the age derived from crater statistics (<1,000 km 2 , Warner et al., 2015), but the crater density argues for a floor unit younger than the fluvial activity of Jezero (Goudge et al., 2012; Marchi, 2021; Schon et al., 2012; Shahrzad et al., 2019).…”

Section: Introductionmentioning

confidence: 99%

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The Complex Exhumation History of Jezero Crater Floor Unit and Its Implication for Mars Sample Return

et al. 2023

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During the first year of NASA's Mars 2020 mission, Perseverance rover has investigated the dark crater floor unit of Jezero crater and four samples of this unit have been collected. The focus of this paper is to assess the potential of these samples to calibrate the crater‐based Martian chronology. We first review the previous estimation of crater‐based model age of this unit. Then, we investigate the impact crater density distribution across the floor unit. It reveals that the crater density is heterogeneous from areas which have been exposed to the bombardment during the last 3 Ga to areas very recently exposed to bombardment. It suggests a complex history of exposure to impact cratering. We also display evidence of several remnants of deposits on the top of the dark floor unit across Jezero below which the dark floor unit may have been buried. We propose the following scenario of burying/exhumation: the dark floor unit would have been initially buried below a unit that was a few tens of meters thick. This unit then gradually eroded away due to Aeolian processes from the northeast to the west, resulting in uneven exposure to impact bombardment over 3 Ga. A cratering model reproducing this scenario confirms the feasibility of this hypothesis. Due to the complexity of its exposure history, the Jezero dark crater floor unit will require additional detailed analysis to understand how the Mars 2020 mission samples of the crater floor can be used to inform the Martian cratering chronology.

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Section: Review Of Crater‐based Age Determination Of the Dark Crater ...supporting

confidence: 92%

Section: Review Of Crater-based Age Determination Of the Dark Crater ...supporting

confidence: 83%