Stratigraphic relationships in Jezero crater, Mars: Constraints on the timing of fluvial-lacustrine activity from orbital observations

Abstract

On February 18, 2021 NASA's Perseverance rover landed in Jezero crater on Mars. In the past, the crater was filled with water, forming a lake, and in the western part of the crater an ancient delta is preserved. Part of the present-day crater floor has been interpreted to represent a lava flow that was deposited after the lake dried out, meaning that the floor unit would be younger than the western delta. In order to understand how the Jezero crater lake has developed over time, including the potential timeline and environments of habitability, it is necessary to work out the relations between the geologic units in Jezero crater. In this work, we have analyzed orbital images of Jezero crater and reveal how the crater floor and delta deposits relate to each other in time. Our results show that at least some of the deltaic deposits in Jezero overlie the youngest crater floor unit(s). It is therefore possible to learn broadly when fluvial activity in the crater has been effective from the age of the crater floor. Our work presents hypotheses that can be tested by Perseverance to advance our knowledge of how the area has evolved geologically over time.