Chemical composition of the first rocks sampled by the Perseverance rover in Jezero crater, Mars - Observatoire de Paris Access content directly
Conference Papers Year : 2021

Chemical composition of the first rocks sampled by the Perseverance rover in Jezero crater, Mars

Tanja Bosak
  • Function : Author
Pierre Beck
Kathleen Benison
  • Function : Author
Karim Benzerara
Olivier Beyssac
Adrian Brown
  • Function : Author
Barbara Cohen
  • Function : Author
Kenneth Edgett
  • Function : Author
Kenneth Farley
  • Function : Author
Woodward Fischer
  • Function : Author
Thierry Fouchet
Travis Gabriel
  • Function : Author
Kevin Hand
  • Function : Author
Elisabeth Hausrath
  • Function : Author
Jeffrey Johnson
Stephane Le Mouelic
  • Function : Author
Lucia Mandon
Lisa Mayhew
  • Function : Author
Scott Mclennan
  • Function : Author
Pierre-Yves Meslin
Marion Nachon
  • Function : Author
Sylvestre Maurice
  • Function : Author
Ann Ollila
Cathy Quantin-Nataf
Violaine Sautter
Sandra Siljestrom
  • Function : Author
Justin Simon
  • Function : Author
David Shuster
  • Function : Author
Jesse Tarnas
  • Function : Author
Arya Udry
  • Function : Author
Anastasia Yanchilina
  • Function : Author
Meenakshi Wadhwa
  • Function : Author
Benjamin Weiss
  • Function : Author
Peter Willis
  • Function : Author
Roger Wiens
  • Function : Author

Abstract

The Perseverance rover will collect its first sample in August 2021 by coring low-standing, polygonally fractured rocks associated with the crater-retaining terrain to the southeast of Jezero delta. Future laboratory analyses of this first sample could determine the origin and depositional/emplacement age of the fractured unit in Jezero crater. Depending on the lithology, further analyses can address: 1. the potential utility of this unit for the constraining the age of the delta and possibly calibration of the crater chronology of Mars; 2. the evolution of martian interior, surface and climate. The dusty polygons are flat on a m-to-cm scale, largely lack visible layering and occasionally grade into darker, higher-standing nubs. WATSON and SuperCam Remote Micro-Imager (RMI) images of these rocks reveal mm-scale light and dark patches and specular reflection in a matrix with otherwise difficult-to-see grains. Analyses by SuperCam laser-induced breakdown spectroscopy (LIBS) and visible and infrared spectroscopy (VISIR) do not support a compositional distinction between the low areas and nubs, suggesting two different weathering expressions of the same starting material. The same analyses reveal hydration signals on the surfaces of all these rocks and suggest alteration by fluids, whereas the dark mm-to-cm scale pits, holes and reflective patches on the rock surfaces indicate wind abrasion. The low-standing rocks are compositionally heterogeneous at the scale of LIBS spot raster spacings (2-5 mm), with a bulk composition consistent with basaltic andesite. The major element compositions of some individual ~0.3 mm-diameter LIBS spots are consistent with iron oxides, ilmenite, various pyroxene minerals, feldspars and glass-like phases enriched in SiO2. This supports the presence of pure mineral grains at this scale. VISIR data point to a potential mixture of iron-rich phyllosilicate and iron oxyhydroxide on rock surfaces. These observations are consistent with the interpretations of the polygonally fractured rocks as either fine-grained sandstone or tuff. New constraints on their origin are expected in August 2021, when WATSON, SuperCam, PIXL and SHERLOC will be able to examine the texture and composition of abraded rocks millimeters below the dusty rock surfaces and any rock surface coatings.
No file

Dates and versions

obspm-03903829 , version 1 (16-12-2022)

Identifiers

Cite

Tanja Bosak, Pierre Beck, Kathleen Benison, Karim Benzerara, Olivier Beyssac, et al.. Chemical composition of the first rocks sampled by the Perseverance rover in Jezero crater, Mars. AGU Fall Meeting 2021, Dec 2021, Nouvelle-Orléans, United States. ⟨obspm-03903829⟩
14 View
0 Download

Share

Gmail Mastodon Facebook X LinkedIn More