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Is the Jezero Landform a Delta? Identifying Channel Networks on Planetary Bodies

Session: Geomorphology and Surface Processes Across the Solar System

Presenting Author:

Piret Plink-Bjorklund

Authors:

Plink-Bjorklund, Piret¹, Gezovich, Luke², Henry, Jack³, Hansford, Mark⁴

(1) Department of Geology and Geological Engineering, Colorado School of Mines, Golden, Colorado, USA, (2) Geology and Geological Engineering, Colorado School of Mines, Golden, Colorado, USA, (3) Earth, Environmental and Planetary Sciences, Rice University, Houston, TX, USA, (4) Eden GeoPower, Vancouver, BC, Canada,

Abstract:

The significance of ancient Martian deltas and our ability to identify them cannot be overstated. Martian deltas are promising targets for finding signatures of life because on Earth deltas support and preserve biodiverse ecosystems. Martian deltas also contain hydrated minerals, which could be vital for in-situ water collection during manned missions or the production of propellants. As deltas only form where rivers enter a standing body of water, preserved deltas are key indicators of paleo-shorelines and water levels of ancient Martian lakes and oceans.

Jezero Crater was selected as the landing site for NASA’s Perseverance rover based on the interpretation of its fan-shaped channel network as a delta. The Perseverance mission is a significant milestone in planetary exploration that has exceeded expectations and collected unprecedented data from the Martian surface. However, its exploration strategy is guided by the assumption that this paleochannel network is deltaic in origin. What if this assumption is incorrect?

In this study, we test the origin of the Jezero channel network using quantitative morphometric analysis from satellite imagery. Our results show that the Jezero network is morphometrically inconsistent with Earth deltaic systems. We compare these findings to the morphometric characteristics of the Eberswalde Crater, a channel network that is consistent with deltaic origin.

We interpret the Jezero channel network as a fluvial fan—a terrestrial landform typical of environments with high sediment supply and marked seasonal or interannual rainfall variability. On Earth, such settings are less favorable for the long-term stability of surface water and may be less promising targets for preserving biosignatures. The presence of a crater lake at Jezero is supported by independent evidence, and parts of the system can be deltaic - the Perseverance mission is not compromised. Yet, these findings highlight the need for rigorous criteria to accurately identify landforms not only on Mars but also on other planetary bodies like Titan. Beyond identifying deltas for future missions, recognition of fluvial fans may provide new insights into past Martian fluvial activity, as well as rainfall intensity and intermittency. Furthermore, our results suggest that the processes governing the formation of deltaic and fluvial fan channel networks — diffusion and surface runoff erosion, respectively — are fundamentally similar on Earth and Mars and shape distinct channel network morphology on both planets.