Olivine-Carbonate Mineralogy of Jezero Crater

TL;DR

This study uses CRISM data to analyze mineralogy in Jezero Crater, revealing olivine and carbonate associations that suggest serpentinization and provide insights into Mars's thermal and tectonic history.

Contribution

It identifies specific olivine and carbonate mineral associations in Jezero Crater, offering new insights into Mars's geological history and potential habitability.

Findings

Mg-carbonates are associated with olivine-rich lithologies.

Olivine contains relatively high Fe content.

Associations suggest serpentinization processes on early Mars.

Abstract

A well-preserved, ancient delta deposit, in combination with ample exposures of Mg-carbonate rich materials, make Jezero Crater in Nili Fossae a compelling astrobiological site and a top candidate for future landed missions to Mars. We use CRISM observations to characterize the surface mineralogy of the crater and surrounding watershed. We have identified a three- endmember sequence of olivine-bearing lithologies that we hypothesize are distinguished by their Mg content. We find that Mg-carbonates are consistently identified in association with one of the olivine-bearing lithologies, although that lithology is not fully carbonatized. Surprisingly, this lithology contains relatively Fe-rich olivine. We address a range of formation scenarios, including the possibility that these olivine and carbonate associations are indicators of serpentinization on early Mars. These deposits provide an opportunity for deepening our understanding of early Mars by revealing the thermal history of the martian interior and potentially changes in its tectonic regime with time.