FRACTURES AND LINEAMENTS IN JEZERO CRATER (Invited Presentation)

Jezero crater hosts a rich variety of geomorphological features, which together record an equally rich geological history. The Mars 2020 Perseverance Rover is exploring Jezero’s varied terrain with the goal of understanding its geological history and its potential for preserving biosignatures. This exploration is naturally multi-faceted, comprising investigations of the materials and structures currently preserved in the crater, using both pre-landing orbital data and observations collected in-situ by Perseverance. Here, we report on investigations of Jezero’s geomorphological lineaments, focusing on fractures and their significance for Jezero’s geological history.

Lineaments in general are the surface expressions of structures reflecting either brittle or ductile deformation of the host rock. At Jezero, we have mapped several distinct suites of lineaments that we interpret as brittle fractures. Fractures are important to understand because, in general, they provide conduits for fluid flow; they represent planes of mechanical weakness that can signal bulk mechanical properties of the rocks in which they form; and, on Mars, represent possible sites of astrobiological interest. Using both orbital and in-situ data, we systematically analyze the characteristics of these fractures. We focus on fracture geometry, which can provide critical information about the deformation history of a region, and relative timing, which can provide valuable relative chronological or stratigraphic information. We are particularly interested in the three-dimensional geometry of fractures expressed at the surface. The RIMFAX ground-penetrating radar instrument on the Perseverance Rover provides the opportunity to characterize the subsurface geometry of Jezero’s fractures, thereby adding a critical dimension to the analysis of these features. By documenting fracture morphologies, orientations, scale, spacing, and spatial patterns and interactions, including subsurface information wherever possible, we seek to understand the nature and sequence of deformation in Jezero crater.