Stable Isotope (H, N, O) Variations in the Solar System: a cosmochemistry overview. Bernard Marty CRPG-CNRS Nancy France

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1 Stable Isotope (H, N, O) Variations in the Solar System: a cosmochemistry overview Bernard Marty CRPG-CNRS Nancy France 1- Objects and reservoirs 2- Isotope variations in the solar system 3- Possible causes

2 Primitive météorites - Chondrites - Allende 1 mm Mes. Opx. Di. Mel. Sp. M. Ol. 100 μm Ca, Al-rich inclusion (CAI) (up to 10%) Chondrule (up to 80%) 100 μm 1 μm Matrix (Silicates, phyllosilicates)

3 Primitive meteorites 1- Calcium-Aluminium-rich Inclusions -CAI typically cm mineralogy dominated by phases having very high vaporization (or condensation) temperatures (T >1500 K) oldest solar system objects ( ± 0.55 Ma; Amelin et al, 2002) hosts for many isotopic anomalies Short-lived (extinct) radionuclides Stable nuclides: oxygen isotopes Nucleogenetic anomalies

05-1 mm Spherules made of olivine, pyroxene, glass,

4 Primitive meteorites : the Rosetta Stone of the Solar system 2- Chondrules, typically mm Spherules made of olivine, pyroxene, glass, metal Formed ~2 (1-5) Ma after oldest CAIs Olivine Pyroxene Glass Metal

5 Dauphas & Chaussidon, 2011 CAI have sampled unprocessed solar gas (solar N and O) Chrondules have sampled processed reservoir(s) Several Ma to make the different chondrules now found in chondrites : - cycles of chondrule formation - chondrites are secondary objects

6 Primitive meteorites 3- Fine-grained matrix, cementing CAIs and chondrules Aggregates of low-t and high-t phases Rich in volatile elements : - organics, main host of C, N and probably noble gases - phyllosilicates, main hosts of water, hydrothermal alteration in the parent body (?)

7 Organics IOM embedded with cristalline silicates, solar system origin likely hosts the most extreme isotopic excursions of H, N, O Busemann et al. (2006) IOM in CR chondrite Alexander, 2009 Extreme O isotope anomalies in silicate embedded in IOM, silicon is isotopically solar Aléon et al., 2005

8 Cometary Cometarysamples on on Earth Earth IDPs IDP Messenger, 2000 Ultra-Carbonaceous Ultra-Carbonaceous Antarctic Antarctic Micrometeorites Micrometeorites UCAMMs UCAMMs (Duprat (Duprat et et al., al., 2010) 2010) ( ) The C-rich phase represent vol% -> Similar to CHON particles (comet 1P/Halley)

9 Large amount of of crystalline phases in in ET material Di Carbonaceous matter Py En 96 En 93 Fo nm 200 nm The ISM is dominated by amorphous grains Fe-Ni sulfide Kemper et al. ApJ nm En 100

10 ε unit : part per 10,000 Solar system material is very well mixed Warren, 2011

Light elements : large isotopic variations in solar system reservoirs : D/H ~500 % 13 C/ 12 C > 10-20 % 15 N/ 14 N ~ 500 % 18 O/ 16 O > 6 % ( 50 %) = 17 O/ 16 O > 6 % ( 50 %)

11 Light elements : large isotopic variations in solar system reservoirs : D/H ~500 % 13 C/ 12 C > % 15 N/ 14 N ~ 500 % 18 O/ 16 O > 6 % ( 50 %) = 17 O/ 16 O > 6 % ( 50 %) H, C, N, O mostly in gaseous state in interstellar medium, protostellar clouds and nebulae H 2, (He) CO, N 2 > 99 % gas (solid) chemistry Interactions between photons and gas

12 Isotope cosmochemistry of hydrogen Solar Earth 20 Comets Interstellar ice In In primitive primitive meteorites meteorites 10 Carbonaceous chondrites Phyllosilicates Phyllosilicates : : aqueous aqueous alteration alteration on on the the parent parent body body Insoluble Insoluble organic organic matter matter Number of cases Chondrules Ordinary chondrites Hydrated minerals Micrometeorites Stratospheric IDPs D/H (x 10 6 ) Ref : oceans Robert, 2002

13 Isotope cosmochemistry of hydrogen 103P/Hartley2 Solar Earth 20 Comets Interstellar ice In In primitive primitive meteorites meteorites 10 Carbonaceous chondrites Phyllosilicates Phyllosilicates : : aqueous aqueous alteration alteration on on the the parent parent body body Insoluble Insoluble organic organic matter matter Number of cases Chondrules Ordinary chondrites Hydrated minerals Micrometeorites Stratospheric IDPs D/H (x 10 6 ) Ref : oceans Robert, 2002

14 Isotope cosmochemistry of hydrogen Variations Variations of of the the D/H D/H ratio ratio by by a a factor factor of of ~10, ~10, Even Even larger larger D/H D/H variations variations in in insoluble insoluble organic organic matter matter of of primitive primitive meteorites meteorites 103P/Hartley2 Solar Earth 20 Comets 10 Interstellar ice Carbonaceous chondrites Isotope Isotope fractionation fractionation by by exothermic exothermic ionmolecule ionmolecule reactions reactions at at low low T, T, e.g., e.g., 10 H 3+ + HD H 2 D H K CH 3+ + HD CH 2 D + + H K Number of cases Chondrules Ordinary chondrites Hydrated minerals Micrometeorites Stratospheric IDPs C2H 2+ + HD C 2 HD + + H K (Millar (Millar et et al., al., 2000; 2000; Herbst, Herbst, 2002) 2002) D/H (x 10 6 ) Ref : oceans Robert, 2002

Isotope cosmochemistry of hydrogen D/H D/H ratio ratio of of different different aromatic aromatic and and aliphatic aliphatic molecular molecular fragments fragments of of IOM IOM from from

Correlation Correlation rules rules out out IOM IOM formation formation from from observed observed interstellar interstellar molecules molecules D/H D/H composition composition of of IOM

15 Isotope cosmochemistry of hydrogen D/H D/H ratio ratio of of different different aromatic aromatic and and aliphatic aliphatic molecular molecular fragments fragments of of IOM IOM from from the the Orgueil Orgueil meteorite meteorite D-enrichment D-enrichment in in IOM IOM is is correlated correlated with with the the C H C H bond bond dissociation dissociation energy energy Correlation Correlation rules rules out out IOM IOM formation formation from from observed observed interstellar interstellar molecules molecules D/H D/H composition composition of of IOM IOM and and meteoritic meteoritic water water : : exchange exchange with with a a deuterium-rich deuterium-rich reservoir reservoir in in the the solar solar system. system. Remusat et al., 2006

16 Noble gas isotopes : evidence for fractionation upon ionization Noble gases are trapped in a, or several, minor phase(s) which make less than 1 % of chondrites (Lewis et al., 1975) Similar abundance and isotope patterns among different classes of meteorites (CC, OC, ureilites ) (Huss, 1996; Busemann, 2000) Relative to Solar, noble gases are enriched in heavy isotopes, e.g., 1 % / amu for xenon, plus minor additions of nucleosynthetic isotopes (Gilmour, 2009) solar Extent of fractionation consistent with ionization by hard UVs Ott, 2002

17 Fractionating xenon upon ionization : an efficient way to fractionate isotopically noble gases Frick et al., 1981, Bernatowicz et al., 1987, Hohenberg et al., 2002, Ponganis et al., 2004; Marrocchi et al., 2011 Anthracite with UV no UV Anthracite Xe ionization during evaporation-condensation of carbon results in heavy Xe isotope enrichment of 1.4 % per mass unit for Xe trapped in solid phase. (Marrocchi et al., 2011)

18 Carbon Ion probe analysis of C isotopes in the skin of lunar soil grains (Hashizume et al., 2004)

19 Oxygen Scott, 2007 Krot, 2007 Defines genetic families at the meteorite (asteroid) and planetary scale

20 NASA Discovery program PI : Don Burnett, Caltech Oxygen, nitrogen, noble gas isotope compositions of the solar nebula Nebula Sun Solar wind

21 launch: August 8, 2001 return: September 8, 2004

22 launch: August 8, 2001 return: September 8, 2004

23 UCLA MegaSIMS laboratory Kevin McKeegan et al.

$Concentrator s fractionation$ using Ne isotopes analyzed at

24 Uncorrected O data SiC quadrant analyzed for O and N isotopes O isotope data corrected for Concentrator s fractionation using Ne isotopes analyzed at ETH zurich along the same radius Corrected data

25 McKeegan et al., 2011

26 Bochsler (2000) Coulomb Drag Model All solar wind samples are depleted in He/H elemental relative to helioseismology solar ratio by about a factor of 2.5. Model assumes that all He/H fractionation all due to Coulomb Drag. With this assumption, fractionations for other isotope ratios can be calculated.

27 McKeegan et al., 2011 Corrected for CD, gravitationnal settling, radiative levitation

28 The carrier of O isotope anomalies : probably 17 O, 18 O-rich water Metal-rich phase(s) formed by oxidation of FeNi in matrix of Acfer 094 Chondrite : evidence for an extremely 17,18 O reservoir in the solar system Sakamoto et al., 2007

29 Nitrogen Two isotopes : Atmosphere 14 N : 272, 15 N : 1 Different nucleosynthetic origins Mostly hosted in IOM and nitrides Detected as CN and HCN in comets

30 Nitrogen Jupiter is 15 N-depleted relative to Earth (Owen et al., 2001) TiN in CAI too (Meibom et al., 2006)

31 Analysis of N isotopes in Genesis Concentrator at Nancy SiC Laser ablation static mass spectrometry Pete Burnard & Laurent Zimmmermann Ims 1280 HR2 ion probe Marc Chaussidon

32 +12 ~ blank GCA Laser ablation static mass spectrometry Mixing between terrestrial N and 15 N-depleted nitrogen -388±183 (2σ) High terrestrial contamination But data point to a SW N end-member different from Terrestrial -347±194 (2σ) δ 15 N data corrected for concentrator fractionation; Only the SW fraction of N was corrected Correction is between 0.2 and 3 per mil, within analytical uncertainty

$Instrumental fractionation$ corrected using SiC target with

33 Ion probe analysis 5 mm 4 areas with up to 15 spots each analyzed along the quadrant radius Instrumental fractionation corrected using SiC target with known N isotope composition Terrestrial Solar wind

34 Protosolar nebula : 14 N/ 15 N = 441 ± 6 (2σ) 15 N/ 14 N = 2.27±0.03 x 10-3 δ 15 N = -383±7 Laser ablation static mass spectrometry (LASMS) Marty et al., 2010 Dense cores (Gerin et al., 2009) Ims 1280 ion probe, Marty, Chaussidon, Wiens, Jurewicz, Burnett., 2011

35 Protosolar nebula : 15 N/ 14 N = 2.27±0.03 x N/ 15 N = 441±6 TiN in CAI 15 N/ 14 N = 2.36± N/ 15 N = 424±7

36 Protosolar nebula : 15 N/ 14 N = 2.27±0.03 x N/ 15 N = 441±6 TiN in CAI 15 N/ 14 N = 2.36± N/ 15 N = 424±7 NH NH 2 D 2 in in dense dense cores, cores, Cold Cold ISM ISM Gerin Gerin et et al al (2009) (2009) Suggests solar system origin for 15 N enrichments

37 Well Well homogenized homogenized reservoir reservoir in in the the innner innner planet planet region region Combined Combined D/H D/H and and N/ N/ N variations variations suggest suggest that that terrestrial terrestrial volatiles volatiles originate originate from from a a reservoir reservoir that that also also sourced sourced asteroidal asteroidal matter matter but but HCN-CN HCN-CN represents represents bulk bulk N in in comets comets??

Nanodiamonds in meteorites Most abundant «Presolar grains» Host of xenon HL enriched in both light and heavy isotopes : nucleosynthetic signature Solar 12 C/ 13 C = 92 Protosolar nebula : 15 N/ 14 N

38 Nanodiamonds in meteorites Most abundant «Presolar grains» Host of xenon HL enriched in both light and heavy isotopes : nucleosynthetic signature Solar 12 C/ 13 C = 92 Protosolar nebula : 15 N/ 14 N = 2.27±0.03 x N/ 15 N = 441±6 Nanodiamonds 15 N/ 14 N = 2.40± N/ 15 N = 417±5 Most nanodiamonds formed in the solar system Mass balance imposes that a few of nanodiamonds only are presolar and host Xe-HL and presumably nucleosynthetic 15 N BUT only one nanodiamond on 10 6 hosts Xe-HL Solar nanodiamonds formed from already evolved solar gas as were CAI?

39 Origin of 15 N excesses Injection of of nucleosynthetic N? (absence of of correlated isotopic anomalies) Photodissociation of of N 2, 2, isoelectronic with with CO, CO, self self shielding (Clayton, 2002), 2002), transfert of of signal signal to to CN, CN, HN.. HN.. Radicals, N-enriched nitrogen N trapped in in solid solid organics Ion-molecule reactions at at LT LT (~10K) (~10K)(Adam (Adam and and Smith, Smith, 1981; 1981; Tervezia & Herbst, Herbst, 2000; 2000; Charnley & Rodgers, 2002), 2002), e.g., e.g., 15 N + CNC + N + C 15 NC K 15 N + HN + 2 N + H 15 NN K 15 N + HCNH + N + HC 15 NH K low low neutrals eg egco, to to minimize backward reactions that that would would consume atomic atomic N (Charnley & Rodgers, 2002) 2002)

40 Evidence for ion-molecule reactions rather than self shielding Rough correlation between 15 N and D excesses in IOM (Busemann et al., 2006) 15N/ 14N Aléon, 2010 D/H correlation between D and 15 N excesses in chondritic IOM, IDPs and Hale Bopp HCN

41 Evidence for ion-molecule reactions rather than self shielding 15N/ 14N Aléon, 2010 D/H

42 Evidence for ion-molecule reactions rather than self shielding Isotope fractionation factor α : α i exp( E i /kt) Where E is the difference in zero point energy between the different isotopologues Log(α N ) = E N / E H x Log(α H ) Slope gives ratio of exothermicities of reactions Aléon, 2010 Correlation consistent with ion molecule reactions for both H and N isotope fractionations Exothermicities consistent with ion-molecule reactions for H and N

43 Co-existence of different fractionating processes Hashizume et al. (2011) ion probe analysis of stable isotopes in IOM of Yamato , a CR2 chondrite

44 Co-existence of different fractionating processes Hashizume et al. (2011) ion probe analysis of stable isotopes in IOM of Yamato , a CR2 chondrite Correlation between O and C isotopes : supports self-shielding

45 Co-existence of different fractionating processes Hashizume et al. (2011) ion probe analysis of stable isotopes in IOM of Yamato , a CR2 chondrite Correlation between O and C isotopes : supports self-shielding Correlation between N and H isotopic excesses supports common processing

46 Co-existence of different fractionating processes Hashizume et al. (2011) ion probe analysis of stable isotopes in IOM of Yamato , a CR2 chondrite Correlation between O and C isotopes : supports self-shielding Correlation between N and H isotopic excesses supports common processing No correlation between C,O versus H,N

$Co-existence of different fractionating processes Hashizume et al.$

47 Co-existence of different fractionating processes Hashizume et al. (2011) ion probe analysis of stable isotopes in IOM of Yamato , a CR2 chondrite Correlation between O and C isotopes : supports self-shielding Correlation between N and H isotopic excesses supports common processing No correlation between C,O versus H,N Two Twotypes of of processes Self Self shielding for for C, C, O Ion-molecule reactions for for H, H, N

inclusions inclusions of of CR CR clan clan meteorites meteorites Not Not correlated

48 Clasts Clastsin in Isheyevo meteorite :: Briani et al., 2009 Bonal et al., N enrichments enrichments up up to to 5,000 5,000 In In IOM IOM and and inclusions inclusions of of CR CR clan clan meteorites meteorites Not Not correlated correlated with with D/H, D/H, spallation spallation?? Solar Solar flare flare nucleosynthesis nucleosynthesis??

49 Clasts Clastsin in Isheyevo meteorite :: Ne-N Ne-Ncoupled analysis by by laser laser ablation static staticmass spectrometry Cometary

50 Ne isotope data of meteorites and lunar soils (Black and Pepin, 1972) 0.8, 0.9 Production by spallation interaction with cosmic rays

Clasts Clastsin in Isheyevo meteorite :: Extrapolation Extrapolation to to 21 21 Ne/ Ne/ 22 22 Ne Ne ~1 ~1 (pure (pure spallation spallation endmember) endmember) gives gives δ δ 15 15 N ~ ~

51 Clasts Clastsin in Isheyevo meteorite :: Extrapolation Extrapolation to to Ne/ Ne/ Ne Ne ~1 ~1 (pure (pure spallation spallation endmember) endmember) gives gives δ δ N ~ ~ 5,000 5,000,, similar similar to to highest highest values values measured measured by by ion ion probe probe in in Isheyevo Isheyevo δ 15 N up to ~5,000 Pure CR spallation : 21 Ne/ 22 Ne 1 Cometary

52 Temporal evolution of stable isotope variations Gas epoch

$van Dishoeck, 2006 10 K required to induce large N isotope fractionation,$

54 van Dishoeck, K required to induce large N isotope fractionation, CO depletion, explains why isotope excursions more restricted for C and O

55 Solar system stable isotopes The The Earth Earthand and inner innerplanets planetsare are not not anymore anymorethe the isotopic isotopicreference :: made made of of matter matterprocessed processedin in protosolar protosolarnebula nebulagas/solar gas/solarsystem system For For all all major major volatiles volatiles (H, (H, C, C, N, N, O) O) in in the the gas, gas, large large enrichments enrichmentsin in the the heavy heavyand and rare rare isotopes isotopes These Theseenrichments enrichmentscan canonly onlybe beseen seenbecause becausetheir theirsignatures have have been been transfered transferedto to solids solids (organics, (organics, water) water) Unlikely Unlikelyto to be benucleosynthetic nucleosyntheticheritages heritages Require Requireionized ionizedatoms/molecules :: selective selectivephotodissociation of of CO CO for for O and and C, C, possibly possiblyof of N 2 for 2 for N, N, ion-molecule ion-moleculereactions reactionsfor for H, H, and and probably probablyn

Analysis of samples returned by space missions : Apollo, Genesis, Stardust, Marco Polo

Analysis of samples returned by space missions : Apollo, Genesis, Stardust, Marco Polo Bernard Marty Centre de Recherches Pétrographiques et Géochimiques, UPR2300 CNRS Ecole Nationale Supérieure de Géologie