Stratigraphy Preserved on the Jezero Crater Rim Reveals Repeated Impacts on Early Mars
Year: 2026
Type: article
Abstract: The outer slopes of the western Jezero crater rim are hypothesized to expose sections of Early‐ to Pre‐Noachian crust uplifted by the Jezero impact, providing an excellent opportunity to investigate the earliest geologic processes active on terrestrial planets. Here, we analyze a ∼75‐m‐thick layered bedrock succession explored by the Perseverance rover on the outer Jezero crater rim, informally named the Broom Point member of the Witch Hazel Hill formation, to reconstruct its emplacement processes. Layering is steeply inclined and offset by rim‐transverse faults, consistent with uplifted pre‐impact target rock of Noachian age. Lithofacies include clast‐ and matrix‐supported melt‐bearing breccias, a planar‐laminated to potentially cross‐stratified facies containing candidate accretionary lapilli, and an unstratified to weakly laminated facies, with angular silt‐sized grains. These lithofacies are interpreted as the products of concentrated, ground‐hugging density flows, dilute surges and fall produced by explosive volcanism or impacts. However, millimeter‐ to sub‐millimeter‐diameter glassy spherules with vesicular, fluidal and agglutinated morphologies are also present throughout the section, including as a ∼20‐cm‐thick framework‐supported layer. Their morphologies, compositions and distributions appear inconsistent with diagenetic or volcanic spherules, and instead resemble spherules produced by impacts, suggesting that the lithofacies of the Broom Point member were predominantly emplaced as impactites. Geological cross sections and stratigraphic columns were constructed through the unit, and allowed us to reconstruct the depositional evolution of these deposits. The section preserves repeated phases of flow and fall, and intercalated proximal and distal ejecta, suggesting that Mars' ancient stratified crust preserves evidence for repeated impacts early in its history.
DOI: 10.1029/2026je009779
Authors: Alexander J. Jones, Sanjeev Gupta, Robert Barnes, Samantha Gwizd, Kathryn M. Stack, Briony Horgan, Sanna Alwmark, Athanasios Klidaras, Eleni Ravanis, Sarah Fagents, Gerhard Paar, James F. Bell, Justin N. Maki, Margaret Deahn, Candice Bedford, Nicolas Mangold, Michael Bramble, Justin I. Simon, Lisa Mayhew, Cathy Quantin‐Nataf, Larry Crumpler, Christoph Traxler, Chris Herd, Olivier Beyssac, Nicolas Randazzo, Uni Árting, Roger C. Wiens, Kenneth A. Farley
Institutions: Imperial College London, Jet Propulsion Laboratory, Purdue University West Lafayette, Lund University, University of Hawaiʻi at Mānoa, Joanneum Research, Arizona State University, Centre National de la Recherche Scientifique, Laboratoire de Planétologie et Géosciences, Nantes Université, National Aeronautics and Space Administration, Johnson Space Center, University of Colorado Boulder, École Normale Supérieure de Lyon, Laboratoire de Géologie de Lyon : Terre, Planètes et Environnement, Université Jean Monnet, Université Jean Monnet, New Mexico Museum of Natural History and Science, VRVis GmbH (Austria), University of Alberta, Sorbonne Université, Muséum national d'Histoire naturelle, Institut de minéralogie, de physique des matériaux et de cosmochimie, Jarðfeingi, California Institute of Technology
Language: English
Subfield: Space and Planetary Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,070
Funders: UK Space Agency, Canadian Space Agency
Awards: G4442510332, G6384485327, G6913555990
OpenAlex ID: W7168375414