3D-virtual geological exploration of the delta units, Jezero crater, Mars.

Abstract

The first long-distance observations made by Perseverance from the Kodiak butte con- firmed Gilbert-type delta deposition within a closed-lake system in Jezero crater, Mars. Several outcrops at the delta proper were also imaged later during science campaign but their geology and potential relationship to Kodiak needed to be explored. In this thesis, Perseverance image data with a focus on Mastcam-Z and Supercam was used in digital outcrop modeling, applying the Structure-From-motion (SFM) photogram- metry software Agisoft Metashape and georeferenced with SPICE-derived position and orientation. The digital outcrop models (DOMs) were analyzed in the Pro3D software, extracting dip and strike measurements as well as scale bars for determining 2D-clast size-frequency distributions with the ImageJ software. Seven high-resolution, textured and accurate digital outcrop models were created. Evidence gathered from the DOMs shows sedimentary facies associated with Gilbert-type delta stratal architectures. Fore- set and lower foreset facies were identified at the outcrops Franklin Cliff, Whale Moun- tain, Kodiak and Scarp A. Topset facies were found at every outcrop, except Scarp D. “Whale Mountain“ also displays a prominent mouth bar deposit. Six clast samples were collected, all associated with a fluvial origin. Three samples were identified as channel base deposits in a topset environment, one interpreted as a foreset debrite, one debris flow, and one high-energy flood conglomerate. Topset-foreset boundaries differ in alti- tude between outcrops, suggesting different phases of delta progradation. Inferred paleo flows from Whale Mountain and Franklin Cliff link those to the delta strata found at Kodiak, further indicating that the butte was once part of the delta. This thesis demon- strates how digital outcrop models can be used to conduct virtual fieldwork also in the remote environment of Mars.