Orbital Context and In Situ Observations of Nili Fossae Olivine-Carbonate - Observatoire de Paris Accéder directement au contenu
Communication Dans Un Congrès Année : 2021

Orbital Context and In Situ Observations of Nili Fossae Olivine-Carbonate

Adrian Brown
  • Fonction : Auteur
Roger Wiens
  • Fonction : Auteur
Patrick Pinet
Lucia Mandon
Stephane Le Mouelic
  • Fonction : Auteur
Lisa Mayhew
  • Fonction : Auteur
Arya Udry
  • Fonction : Auteur
Briony Horgan
  • Fonction : Auteur
Nathalie Turenne
  • Fonction : Auteur
Fred Calef
  • Fonction : Auteur
Edward Cloutis
  • Fonction : Auteur
Thierry Fouchet
Maria-Paz Zorzano
  • Fonction : Auteur
Eleni Ravanis
  • Fonction : Auteur
Sarah Fagents
  • Fonction : Auteur
Alberto Fairen
  • Fonction : Auteur

Résumé

Perseverance landed at the Octavia E. Butler landing site next to the Séítah dune region in Jezero crater on 18 February 2021, in close proximity to the largest exposed carbonate deposit on Mars. These carbonate signatures have been shown to be associated with the strongest olivine signatures at Jezero crater (Goudge+ 2015, Brown+ 2020). Alteration of olivine can lead to carbonate+H2 production, an energy source for microbes (Mayhew+, 2013). The question of the origin of the olivine-carbonate unit represents both an opportunity and a challenge for the rover mission and future sample return efforts. Carbonate The landing site is not near the region of carbonate detections (Figure 1), however the rovers westward traverse will take us over the carbonates on approach to the crater rim. No reliable indications of the 2.5 m carbonate band have yet been convincingly detected by the SCAM VISIR instrument. Olivine Studies of the olivine-carbonate unit concluded the olivine is relatively Fe-rich and coarse grained (mm: Poulet+ 2007, Clenet+ 2013). The strongest in-situ olivine signatures are found in dune material analysed by LIBS/VISIR (Beyssac+ Mandon+ this conf). This grain size characterization work may be used to investigate the interaction of olivine with water and CO2 (Escamilla-Roa+ 2020). These surface-gas processes are enhanced when olivine is in fine grain form. Ash dispersal modeling is ongoing (Ravanis+ this conf) to determine the range different sized ash particles could have traveled on ancient Mars. We cannot directly compare the 1 m band for CRISM and VISIR, so we developed a new method that measures the curvature of three points on the absorption bands to assess their relative Fo# shifts and applied it to both datasets. Lab spectroscopy will be used to assess spectral variations with composition versus grain size. Two key factors driving the Fo# are mantle composition and melt temperature. Brown+ (2020) estimated a range of Fo44-65 for the most redshifted olivine observed by CRISM. McGetchin+Smythe (1978) showed that an Fe-rich mantle composition would produce highly viscous lavas and suggested an upper bound of Fo70 for olivine. Understanding the astrobiological potential of the olivine-carbonate unit is a priority of M2020 (Farley+ 2020) and we will speculate on potential formation models in this contribution.
Fichier non déposé

Dates et versions

obspm-03903776 , version 1 (16-12-2022)

Identifiants

Citer

Adrian Brown, Roger Wiens, Sylvestre Maurice, Patrick Pinet, Lucia Mandon, et al.. Orbital Context and In Situ Observations of Nili Fossae Olivine-Carbonate. AGU Fall Meeting 2021, Dec 2021, Nouvelle-Orléans, United States. ⟨obspm-03903776⟩
16 Consultations
0 Téléchargements

Partager

Gmail Mastodon Facebook X LinkedIn More