SMART LANDER FOCUSED TECHNOLOGY MAR. 2001 MONTHLY REPORT

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Martian Phyllosilicates Recorders of Aqueous
Processes October 21-23, 2008 Paris,
France Discussion Summary Jean-Pierre Bibring,
David Beaty, David Bish, Janice Bishop, Jack
Mustard, Eldar Noe Dobrea, Sabine Petit, Francois
Poulet, Leah Roach
Recommended bibliographic citation Bibring, J-P.,
D.W. Beaty, D. Bish, J. Bishop, J.F. Mustard, E.
Noe Dobrea, S. Petit, F. Poulet, L.H. Roach,
2008, Martian Phyllosilicates Recorders of
Aqueous Processes  Discussion Summary.  Posted
November, 2008 by the Institut d'Astrophysique
Spatiale (IAS) at http//www.ias.u-psud.fr/Mars_Ph
yllosilicates/phyllo/5.20Thursday20morning/Phyll
o_Discussion_summary.ppt
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Consensus Position on Status (Oct. 2008) of
Phyllosilicate Mineral Detections on Mars
The participants considered many possible mineral
detections from OMEGA and CRISM data.  Some
spectral interpretations were considered to be
distinct and well represented in the mineral
libraries, while other spectral signatures were
less absolutely diagnostic of specific mineral
species. The meeting participants considered two
broad classes well-supported mineral
interpretations, and mineral identifications that
needed additional information. A partial listing
of these categories follows
More information needed
Generally Accepted by Conference Participants

• Nontronite
• Al-smectite (montmorillonite, beidellite)?
• Fe/Mg-smectite or sepiolite
• Al-mica (illite and/or muscovite)?
• At least one chlorite group mineral?
• At least one kaolin group mineral

• Mixed-layer illite/smectite, smectite/chlorite
• Ca- and Na-zeolite (analcime has been proposed)
• Prehnite
• Pumpellyite, epidote
• Serpentine group

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Phyllosilicates on Mars Key Questions (1 of 5)

• . What are the basic characteristics of the
  phyllosilicate minerals on Mars?
• 1A. What is the range of mineralogic diversity
  of phyllosilicate species on Mars?
• What are the specific species present within the
  larger phyllosilicate groups? What is their
  crystal chemistry and ordering?
• Is there diurnal or seasonal variation in
  hydration state of hydrated minerals?
• Why do Mg/Fe smectites appear to dominate the
  spectral signatures?
• What is the variation in crystalline to poorly
  crystalline to amorphous forms?
• Are there stealth phyllosilicates or
  proto-phyllosilicates on Mars that are not
  visible to VNIR?
• What are the conditions under which these
  minerals equilibrated?
• 1B. What are the non-phyllosilicate mineral
  assemblages associated with phyllosilicate
  minerals on Mars?
• What are associated spectrally neutral phases
  (and how can we use multiple instruments to
  detect them)??
• What are the paragenetic relationships?
• Why do we sometimes have many alteration minerals
  and other times few?
• What does the co-occurrence of sulfates tell us?

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Phyllosilicates on Mars Key Questions (2 of 5)

• 1C. What is the concentration of phyllosilicate
  minerals in the different occurrences in which
  they have been detected?
• Are they a minor or a major component of the
  rocks?
• Does abundance vary by location or timing of
  formation?
• 1D. What is the range of geologic contexts in
  which phyllosilicate minerals are present on
  Mars?
• How many different types of martian environments
  contain phyllosilicates? Important progress has
  been made over past couple years by OMEGA and
  CRISM teams, however, this work is not complete
  and must be continued.
• Systematic variation with lithology of primary
  bedrock?
• What is the relationship between cratering and
  phyllosilicate formation?
• Is there a difference between the shallow
  subsurface and the surface?
• Phyllosilicates in fans (and other sedimentary
  rocks) transported or formed in place?
• Are there systematic variations in phyllosilicate
  mineralogy or geologic setting as a function of
  age?
• What is the relationship between the
  phyllosilicate-rich deposits and fluvial
  networks?
• What is the absolute and relative age of
  phyllosilicate minerals on Mars?

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Phyllosilicates on Mars Key Questions (3 of 5)

• 1E. The orbital mineralogic detections are on a
  scale of 15-20m or greaterwhat do the rocks and
  soils look like in detail?
• What are the mineralogic variations and textural
  relationships at a scale of 1m? 1cm? 100 mm?
• How to scale between km-scale OMEGA and cm-scale
  lab studies?

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Phyllosilicates on Mars Key Questions (4 of 5)

• What are the genetic mechanisms by which
  phyllosilicate minerals formed on Mars?
• 2A. What were the original formation pathways for
  the different phyllosilicate minerals, and what
  were their subsequent alteration pathways?
• Are terrestrial models involving granitic vs
  basaltic parent material adequate for Mars? Do
  we need new models?
• Was there a relationship between the heavy
  bombardment (or other cratering) and
  phyllosilicate formation?
• 2B. Can phyllosilicate-bearing rocks be used to
  infer past environmental conditions on Mars?
• Did phyllosilicates form only in the Noachian
  period (with subsequent redistribution by erosion
  and deposition processes), and how long did this
  happen? Did they also form in younger epochs?
  Are they forming today?
• What do the phyllosilicates imply about how long
  liquid water was available at the surface?
• What do the clays say about the past climate?
• What is the relevance of each mineral?

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Phyllosilicates on Mars Key Questions (5 of 5)

• 3. What is the relationship between the
  phyllosilicate minerals observed in martian
  meteorites and those detected from orbit?
• Several phyllosilicate minerals have been
  detected in martian meteorites, mainly in the
  nakhlites. They were first detected in Nakhla in
  1975, and they were just called 'iddingsite' (a
  general term for a mixture of alteration
  minerals). The minerals are generally smectite,
  illite and ferrihydrite.
• 4. What are the implications of
  phyllosilicate-bearing rocks for the development
  or preservation of pre-biotic chemistry and/or
  biosignatures?
• Were phyllosilicate minerals (especially Fe/Mg)
  resources for life in some way?
• How do phyllosilicates help preserve
  biosignatures in the martian environment

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Phyllosilicates on Mars Summary of Key
Questions, Oct. 2008

• What are the basic characteristics of the
  phyllosilicate minerals on Mars?
• 1A. What is the range of mineralogic diversity?
• 1B. What are the associated non-phyllosilicate
  mineral assemblages?
• 1C. What is the concentration of phyllosilicate
  minerals?
• 1D. What is the range of geologic contexts for
  phyllosilicates on Mars?
• 1E. What is the relationship between the scale
  of the orbital detections and the
  inter-crystalline or inter-granular details of
  the rocks and soils?
• What are the genetic mechanisms by which
  phyllosilicate minerals have formed on Mars?
• 2A. What were the original formation and
  subsequent alteration pathways?
• 2B. Can phyllosilicate-bearing rocks be used to
  infer past environmental conditions on Mars?
• 3. What is the relationship between the
  phyllosilicate minerals observed in martian
  meteorites and those detected from orbit?
• 4. What are the implications of
  phyllosilicate-bearing rocks for the development
  or preservation of pre-biotic chemistry and/or
  biosignatures?

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Investigations needed to address key
questionsFlight Investigations

• EXTREMELY HIGH PRIORITY
• Continue operation of the OMEGA and CRISM
  instruments. Expand these data sets while the
  instruments are in place.
• Continue data reduction of these data sets.
• HIGH PRIORITY
• Acquire ground-truth datasets to confirm spectral
  interpretations.
• Part 1Mars landers
• XRD and IR spectrometer together on a lander to
  bring the two datasets together
• Pick a landing site that has diverse, in situ
  phyllosilicates (hopefully, both MSL and ExoMars)
• Multiple (cheap) landed missions to explore many
  environments
• Penetrate into subsurface ( m) to explore
  variation with depththis is not detectable from
  orbit
• Spend money to miniaturize instruments so more
  can be sent
• Acquire ground-truth datasets Part 2Mars
  Sample Return

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Investigations needed to address key
questionsFlight Investigations

• Better integration of orbital and landed mission
  personnel AND datasets
• Increased joint team meetings across instruments
• LOWER PRIORITY
• Additional orbital instruments
• CRISM's follow-up on OMEGA has opened new avenues
  of research, and similar possibilities might
  exist with TIR if technically feasible.
• Increased spatial resolution has the potential to
  be significant and might be possible using
  well-chosen but fewer bands in VNIR
• NO PRIORITY ASSIGNED UNTIL AFTER MSL
• Measure mineralogy more precisely than with
  CHEMIN
• CheMin will be able to do a good job of
  distinguishing 11 (kaolin and serpentine
  groups), 21 (smectites, vermiculites, illite,
  micas, etc.), and 211 (chlorites)
  phyllosilicates.
• There are several expected issues with specific
  identifications due to the lack of treatments
  used on Earth (e.g., ethylene glycol saturation).

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Investigations needed to address key
questionsTerrestrial analogs, experimental,
theoretical

• (Not listed in priority order)
• Develop a standard set of clay minerals and
  analog materials (well characterized by XRD) for
  comparable studies
• Develop clay mineral standards to circumvent
  impurity of natural samples. In some cases it
  may be possible to synthesize minerals (however
  there is difficulty synthesizing many clay
  minerals at low T). Optimum approach is to use
  purified natural materials.
• Create operational definitions of minerals to aid
  quick identification (a la the clay community)?
• 2. Expand spectral libraries (add mixtures,
  textures, grain sizes and solid- solution series)
• Need to improve the spectral libraries,
  especially of mixtures, textures, and
  solid-solution series. Integrate crystallography
  in mineral identification. Use XRD to confirm
  mineral identifications, and include XRD and
  other additional data with spectral data in
  library.
• 3. Improve our understanding of the detectability
  of phyllosilicates in terrestrial analog sites
• Analog studies using same techniques used on Mars
• Sampling depth differences between instruments
  (esp spectrometers and XRD).

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Investigations needed to address key
questionsTerrestrial analogs, experimental,
theoretical

• 4. Improve interpretive approaches
• Find ways to detect the role of biology in clay
  formation
• Nonlinear spectral modeling to interpret
  abundances
• Thermodynamic modeling of formation
• 5. Laboratory simulations of phyllosilicate
  formation
• Important to understanding impact-induced
  minerals
• Could be a critical direction of research, which
  is gaining momentum in a number of institutes, to
  contribute to understanding out-of-equilibrium
  processes that might have played a key role on
  Mars (and possibly on the early Earth, too).

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A Communication Issue

• What is the best way to deal with variability in
  confidence and level of knowledge?
• How can we distinguish non-unique spectral
  identifications from definitive mineral
  identifications? Quantify confidence of match.
• Communicate to community the different levels of
  confidence for different phases (if we cannot
  identify a phase, describe its main absorptions,
  e.g., Al-OH vibration)?
• Can we set up a quantitative measurement of
  robustness?

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Appendix Mineral terms
Phyllosilicates Smectite general term for a
swelling 21 phyllosilicate with interlayer
cations and H2O molecules, includes nontronite,
montmorillonite, saponite, and beidellite, among
others. Nontronite (Na,K,Ca0.5)0.3(Fe3)2(Si,Al)
4O10(OH)2nH2O, a ferric montmorillonite, Mg and
Fe also possible interlayer cations. Montmorilloni
te (Na,K,Ca0.5)0.3 (Al,Mg)2Si4O10(OH)2nH2O, Mg
and Fe also possible interlayer
cations. Beidellite (Na,K,Ca0.5)0.3Al2(Si,Al)4O1
0(OH)2nH2O, Mg and Fe also possible interlayer
cations. Sepiolite Mg4Si6O15(OH)26H2O Muscovite
KAl2(AlSi3)O10(OH)2 , on Earth the most common
mica mineral. Kaolin group kaolinite, dickite,
nacrite, or halloysite, generally
Al2Si2O5(OH)4 Serpentine group lizardite,
chrysotile, antigorite, generally
Mg3Si2O5(OH)4 Prehnite Ca2Al2Si3O10(OH)2 On
Earth, typically forms as a result of low-grade
metamorphism or hydrothermal alteration. Non-Phyll
osilicates Pumpellyite Ca2(Mg,Fe2)Al2(SiO4)(Si
2O7)(OH)2H2O, An indicator mineral of the
prehnite-pumpellyite metamorphic facies,
typically associated with chlorite, epidote,
quartz, calcite and prehnite. Epidote
Ca2(Al,Fe3)3(SiO4)3(OH). Structurally complex
mineral found in metamorphic and hydrothermally
altered (a common alteration product of
plagioclase) rocks. Analcime NaAlSi2O6H2O.