1995Metic..30..560P 560 tionation Xe-HL) development cantly instead HL-Xe nova with tron-rich topes but precursors 13 supported for of of in the tion this tive Astrophys. supernovae, We tion with port already al. PHIDE: RHENIUM-OSMIUM and CHRONS Planetary USA. [2] decays the 97 fully (1993) other, The the At Condensation References: nonzero Clayton For note, ratio to can between G. such "pure" ejecta the min, have p each to this fact is that age J. process r be [ developed 0.2 0.4 0.6 0.8 1.0 1.4 1.2 formation 4]. anything into without nuclides effect is however, process the a we Sciences, THE Wasserburg, by a Astrophys. achieved different FOR time have fast that equal will J., determinations other Xe-H Taken abundances D. separation Xe-HL F-----...:..._ the are the product of stable Xe 1 219, J\e/J cooling D. Development has (126Xe/ be POSSIBLE I26Xe the little left IRON much first fact and that to evidence acts comes far is else, time-dependent (1989) [I] that at turned r-process 134 of California that end 230-249. lifetimes, between with basically (i.e., © that the face of are from condensates is I29,I3I.I32Xe Xe/ on 6 supernova J., Lewis 124 longer for Xe METEORITES. scenario. of The is in mixing products. of"pure" Meteoritical in other consistent IN to 5000 in Xe a Xe)L not Xe-HL 136 403, Astrophys. value, into Ba part certain of stability, rapid pure for mind "pure" Xe ratio r-process Lunatic for DETERMINATION IRON-NICKEL, with the specific Xe a from R. "normal" half-lives. Institute elements, the Xe-H. originally such very 216-238. < with which Xe-H Te the (-1 may S. as ___ condensates Fig. time extrapolated As (I26Xef124Xe)p. assumptions Xe-H. isotopic will may on Xe-H Xe with and an et a attractive that existence approximately s) Asylum, the events is that J., In have process of 1. this of on of obvious have al. xenon 10000 form timescale shown, I doing r-process r-process precursors subsequently 340, If, these these but In precursors Technology, produced timescale. a r-process [4] (1987) ratio composition D. at to similar __:__:.._ Society order in been timescales in Lattimer A. 613-619. that (final) be so to solution. Division isotopes, isotopes of are the about it to means the is SULFIDE, Papanastassiou, have is we Xe-HL admixed, [e.g., Xe identical evolution produced, I30Xe to Xe time, years Nature, as obvious timescale ejecta OF of normal on From compare 1 account the lime proper. J\e/J Xe-H that I26Ba 15000 ___ Pasadena the decay contributed to one occur J. INTERNAL 3], a of Here usually on of = cooling rather [3] • may serve achieve chemical different M. Fig. a after the [sec] 0, Geological producing the 326, to hand an X chemical with Provided that of Kratz AND via Also, 6 because e). in we where for that may et r-process Xe Xe observation iron order I, than -1 ratios associated CA after a al. process and -=l a J. where 160-162. the a in consider in Xe-H. series OL half-life account K.-L. because signifi­ J. PHOS­ meteor- separa­ separa­ Xe to 91125, (1978) super­ hours. "real" of Xe small Shen, -2 ISO­ frac­ their rela­ neu­ I Abstracts sup­ iso­ 0 and 5% the Xe on 4 hr of of et s by Canyon Sample Odessa Tres element and The in ites, ing tionation tallization microphases, Uncertainties by schreibersite for 0.00018 and compositions iron. in ization, reducing metal-FeS yields determinations. 0.02 into The Re trations that magmatic nonmagmatic which under result show lization centration. the the well-defined, significant Canyon Odessa Tres Sample the principle, Table reaction and the melting We determination parent ofFeNi Re-Os IVB the data the it Castillos aeons; Castillos The relatively steps in NASA is date a IIA (IA) find the (IA) and major Diablo we of redistribution sulfide. FeNi FeNi FeS FeS Diablo FeNi (FeNihP slope significant (all essential 2. conditions on of irons analytical Fe pairs planetesimals. of the partition and levels have on PGE and the with The (2) The Re-Os. can that, the in result 'A uncertainties sheaves; e.g., groups the are whole-rock in (IliA) lA dispersion parent (IliA) metal of the and ~ are melting IV (I (I massive have from low whole-rock, results S; Given Therefore, TABLE metal determined Astrophysics in metal A) 1.64 ofRe 0.07863 A) I and TABLE A rhabdite, of to %o solar in consistent (3) (3) The Re 0.51 20.88 231.5 209.7 the 1.89 1.07 coefficients in Re-Os groups Re and results for phase. essentially obtain planetesimals; Re-Os no their two when IV CRe(MfS) the and, x above] (ppb) segregation during samples presence phase the and and possible on and nebula; influence 8 ± 4 ± schreibersite A 2 ± is J0-11 380 224 2. in IA The Re-Os solar are subsequent dominated I. ± groups refractory the fractionation. finally, at not Os, fractional of This Re-Os Os fractionation a the iron theRe metal 0.00031 Re-Os and a reasonable subsolidus act with 2a). data a- a Tres Re-Os explicitly nebula, later concentrations, with Os 5.65 2428. 1.77 1.26 1982. 164. of the production ( between difference stages of whole-rock I) isochron Re-Os only and 2) crystallization on iron show and (ppb) There for and the on (6) a samples paired ( and Castillos stage. subsequent metal-to-schreibersite partition 6 ± 4) ±I 4 ± the single, cos(M/S) a Data nature analytical by crystallization the as lamella (corresponding FeNi metal precipitation incorporation partial of we metal-phosphide melting meteorites. an 1300 1500 fractionation Os Re-Os a diluents the these phase is range listed. We iron include Tres determined limited consider Using initial analyses 0.6135±6 7 0.4594 0.5103 2.9 187Refi880s 1.9 1.63 in concentrations also or is well-defined for melting isochrons phase, of conclude coefficients. ages FeNi removal System meteorite (3 obtained segregation coexisting Castillos ± ± followed isotope transformations consistent of Re oxidation a group results. ± negative-ion, em of for 0.2 0.2 I870sfi880s (I) suggestion CRe(M/P) Re-Os physical-chemical 0.02 ± of 3 ± and We that are neither the or are x 5 x theRe and II. condensation into of 60 by process of exsolution to IA, systematics for that the have consistent remaining the for the evolution mm) shown I pair (III~ by all fractional ± fractionation massive phases an 0.127 0.2146 0.14371 0.128 0.13168 0.13561 1870sfi880s the best-fit of with iron IIA, of condensation and partition PGE, Re members 45 and fractional irons the metal age also from part from show sulfide FeNi ~ then group) m.y. nor thermal Os data meteorites, Os in the IliA, to 0.09560 4 ± 2 ± are of under analyzed. analyzed of of FeS phase ± that Table one line Os FeS; produce with isotopic concen­ the 4 ± 3 ± 3 ± enables and crystal­ of low Ni did 29.0 4.62 for coeffi- shown the 13 minor of [e.g., crys­ IV enter frac­ FeNi PGE con­ dur­ IliA data can, ion­ that and age not but (5) the the the the Fe on A, of I. ± ± 1995Metic..30..560P ated, cients demonstrate consider data time rate point also disturbance may 3337. internal EXSOLVED time Cambridge ex ine DIVNOE? accordance aqueous within which periments so sian or However, the mesosiderite, been (San and L3 Divnoe mesosiderite the be peratures. Springwater studied. The from cally surprisingly and display all are whereas in very Since Springwater the tories. magnitude result of the prolonged solution far. (2) the found shock chondrite, analyses Acknowledgments: Recently Olivine issue. grains No same The It structural at slowest unclear, mesosiderites yield continue consider 15.8-17.7 the olivines younger Carlos by minor the studied line within of is Division Divnoe olivine olivine I in predicts This a The lamellar 0 (Fa isochron results somewhat possible a application -2°C/m.y.; compositional solutions about Lowitz this most olivine there. equipment features with factor a on [I] in of Olivines low-temperature 23 of lack MA grains means excess of with model cooling forsterite is the that and Petaev variations _ the regular all primary the closely relatively M. and could remains ALH to and compositions 29 that (Fa grains than differences meteorite the other the perfect; obtained II a a FERROMAGNESIAN Contribution Olivines ) mol% 2cr 02138, structure oflamellar act mesosiderite coexistence exsolution. "minima" of miscibility the I. [I], slope Lowitz the Divnoe that and 15 variations and the phosphide; Lowitz of from in the either are age larger of Petaev, _ uncertainty 4.30 84025 2. as and 37 analyses occur in or of down thermodynamic schreibersite (Fe,Mg)Cl2 and in pattern and the © enough possibly Calcalong Divnoe 7, homogeneous Si ) 29 and Fa the Re-Os known an the (3) of the cation corresponding range ofF other USA. [5] young so selected is relative Brearley over aeons. meteorites from Divnoe Meteoritical that for it technique respectively. open meteorite was 4.30 variations, only This among brachinite, olivines, unique. an Rockport far Re-Os even Springwater to was Harvard-Smithsonian a structure analyses are in annealing. gap is of Re of contents indication 5562(905). 250°C have (I) Mg slowly and, experienced to data that suggest ( totals observed to other Divnoe, a observation work system 1.5 age range olivines 2) ± expected minima The compositionally and detect direct Creek at have in to meteorites the opaque minerals them [3] [I] system + an 0.09 widens -2x While especially, has on totals temperatures ferromagnesian as the as display samples Fe was there grains. per Os was recorded fayalite) FeNi-schreibersite exsolution suggest indication cooled showed in (±0.2 model within have Gorlovka that the the in an in Re-Os to measurement at lunar smaller Lowitz, must aeons, them. in The coexisting This respectively. having the in four spaced that pallasite olivine produced supported chemical >97%. that reasonably [ an indication to the slowest with lamellar schreibersite is 1]. OLIVINE: BSE secondary mol% low Lowitz of Exsolved no olivine the of (Springwater age even be coarse-grained the would no meteorite) were oxygens that Society "minima" exsolved that This Among from that were exsolution indicating in decreasing regular olivine a than and due images H3-4 determination of at totals in lamellar grains However, ranges range of mesosiderites as exsolution (Fa Fa). lamellar comparable the Center -16 cooling is studied a Divnoe structure variability FeNi. work the [7] olivine by by studied also Springwater 4.11 to in olivines relatively it high of significantly of low chondrite 18 The olivine massive reheating meteorites, are is NASA different As Springwater the Springwater (90.47-94.31 and of pattern, solid [ ) pm. olivine from of (I) cooling and of permit WHY account analyses. in attempts ± pair compositions 4] temperatures. The in a expected, structure, for as 3.00 the data for • low-temperature temperature. pallasite, rates olivine 20.1-21.0 structure implies the stoichiometry Divnoe disturbance a For 0.11 by natural of terrestrial and solution -400°-450°C. in rocks all below in relatively grant Astrophysics, Provided yields olivine is comparison. schreibersite slow schreibersite olivine EPMA of grains difference furthermore and ferromagne­ with ± and for Divnoe reasons thermal followed history. samples [6] ONLY found at are the for aeons. a 0.01, pallasites to fraction­ is low have that possible NAGW- olivines. are the pallasite does olivines Krymka -340°C cooling olivines shows the similar, and in Lowitz Lowitz that unique a clarify of grains would wt%), grains mol% using rocks in Abstracts two­ oliv­ basi­ tem­ first even with with is late at lack We Ex­ We that [2], his­ not but IN not the the by of in of in a a by 58, distributions pyroxene Petrol., (1980) EDWARD METEORITICS 85-91. Ontario, [8] of ites 1545-1547. 1965. tional Smithsonian employed due partially it Museum. His to with purpose, and collecting or orites he him some entists and involved meteorites pletely born Smithsonian science scientists eral This ing tance Although sorely ment the up sary of its PACT planetary GEOPHYSICAL reflection vey, the was meteoritics. exchanges. make aggressively the development. the References: Petaev Ed During Henderson's 2711-2723. Post-World Henderson's Department The vice evolution grew to new new two Woods trader. foundation set remote of of to Museum due Europe, new national needed Henderson's NASA with Proc. transformed [4] CRATER 102,41-68. involved H. Chesapeake the these see president the London, many positions, remarkable his [8]. days to of development. science, profiles and his meteoriticist, M. to Henderson's BuseckP. Plotkin, as direction collection specimens if stage intuitive the become [2] Hole to of P. became spot administrators his early LPSC keys advances, of training he I. He studying new the As of influential the ( collection, cosmic hunted War day, of eta!. Sack 1929-1965) the HENDERSON love [7] for could extraordinary passion in Astrophysics haggling, also to Ontario a of Philippines, for MA that [I] (LATE and availability Mineral AT efforts, and equipment that result SIGNATURE meteoritics. this negotiate solar 11th, Department Petaev long Bay the the men: II he [3] meteoritics one arguably for grasp R. the Petaev (1990) R. routinely won cross 02543-1598, helped from did for obtain for advances THE ray could meteorites. succeeded administration, new Associated and and growth Schulien (1977)GCA,41, meteorites impact 0. of for system. establishment of career With N6A meteorites 1073-1087. the the however, friends Harvey EOCENE). not track for Sciences of but the and M. lower his the and wanted Stuart research, meteorites, had M.l. LPS SMITHSONIAN with material be the purchase new many the (especially the of equip the 3K7, world's I. Henderson tenure, resourcefulness, Smithsonian's contacted the A strong crater of lengths used Ghiorso as in was a the Henderson former Smithsonian of eta!. Museum, S. XXI, Chesapeake new the Nininger, largest in who and AND directions tremendous the Perry, Press OF atomic vigorous support and Curator the friends USA. were (1980) in Roebling Canada. Philosophy, obtaining him and moving owner to Data he from is embryonic Brearley breed the his and [6] 950-951. 1963. leading Museum became for (1994) THE of backing and unlock defined Soviet his who C. tektites, intuitively largely THE 711-740. to an M.S. a the and Museum's ability a Ganguly physics the was Michigan study his them. Frequently and W. Contrib. of great understand densities Division the for electron generously of in owners developed toward CHESAPEAKE Fund, Bay collection finest System assume Smithsonian Meteorites a wise impact Union, Meteoritics, scientist Poag, centers very meteoritics, a his the world's (1989) A. staunch DEVELOPMENT on INSTITUTION, to $300,000 his shaped of to purchase. or from achievement field University and J. participate and intuitive the mysteries meteorites acquire [5] arranged and understood J. single-mindedness but of good in Mineral. of microprobe), helped (l994)Science, collection newspaper U.S. of between and on a eta!. the basis for Delaney some related the of newly Contrib. provided some first leading arose, by much more generous a Meteorites supporters for the strong continental at Australia, materials-based Geological NASA at their his Sometimes world, collection meteorites and their understanding of full-time 29, (1994) lay this; he of development for the importantly, of in fallen of relationship Petrol., who of and far-sighted olivine fields (I) in the study. of traveled position the J. BAY his the purchases interest this the 182-199. publisher Mineral. U.S. these research. the Western he grant manage­ building seismic­ meteor­ S. tektites. and for leading viewed impor­ 1929- ability within neces­ of origin GCA, where mete­ excit­ was eta!. basic com­ 266, 561 self­ shelf took Sur­ sev­ and IM­ was Na­ OF this sci­ 74, the the for of in to in a