Published January 1962 | Version v1
Book Metadata-only

Os187-isotope abundances in terrestrial and meteoritic osmium and an attempt to determine Re/Os-ages of iron meteorites

Creators

  • 1. Max-Planck-Institut fuer Chemie (Otto-Hahn-Institut) Mainz, Federal Republic of Germany (Germany)
  • 2. Physikalisches Institut der Universitaet Bern (Switzerland)

Description

The isotopic composition of a large number of Os-samples from terrestrial platinum ores and from iron meteorites has been investigated by mass-spectrometry. The observed isotope-ratios Os187:Os186 in Os/Ir-ores and in Os-samples, extracted quantitatively from iron meteorites, vary in limit from 0.88 to 1.41. These variations may be explained by the production of radiogenic Os following the decay of Re187, a natural β-emitter with the lowest known β-energy. Neutron activation analysis proves that Re and Os are common trace elements in iron meteorites. As dating of these bodies by conventional methods suffers from enormous difficulties, the application of the Re/Os method has been studied. From our experiments a primordial Os187:Os186 ratio is assumed and 'minimum ages' are discussed. They differ widely and are found presumably in the range from 3.7 to 5.6x109 yr. (author)

Abstract (French)

Les auteurs ont etudie au moyen de la spectrometrie de masse la composition isotopique d'un grand nombre d'echantillons d'osmium provenant de minerais terrestres de platine et d'holosideres. Le rapport isotopique osmium-187/ osmium-186 observe dans l'osmiure d'iridium et dans les echantillons d'osmium extraits en quantite mesurable des holosideres varie entre 0,88 et 1,41. Ces variations peuvent etre expliquees par la production d'osmium radiogenicjue resultant de la desintegration du rhenium-187, emetteur naturel de rayonnements beta connu comme ayant la plus faible energie beta. L'analyse par activation des neutrons montre que le rhenium et l'osmium se trouvent communement a l'etat de traces dans les holosideres. Comme il est extremement difficile d'evaluer l'age de ces corps en recourant aux methodes classiques, les auteurs du memoire ont examine la possibilite d'utiliser le rapport Re/Os. Apres avoir assume de leurs experiences le rapport osmium-187/osmium-186, ils examinent la question des . Ceux-ci different sensiblement et semblent etre de l'ordre de 3,7 a 5,6 · 109 ans. (author)

Abstract (Spanish)

Los autores han investigado por espectrometria de masas la composicion isotopica de gran numero de muestras de osmio procedentes de minerales terrestres de platino y de meteorites de hierro. Las razones isotopicas 187Os : 186Os observadas en los minerales de Os/Ir y en las muestras de Os, extraidas cuantitativamente de meteoritos de hierro, varian entre 0,88 y 1,41. Estas variaciones pueden explicarse por la formacion de Os radiogenico a consecuencia de la desintegracion del 187Re, que es el emisor natural β que posee la energia β mas baja conocida. Los analisis por activacion neutronica demuestran que en los meteoritos de hierro se suelen encontrar vestigios do Re y Os. Como la determinacion de la edad de estos cuerpos con ayuda de los metodos clasicos tropieza con enormes dificultades, los autores han estudiado la posibilidad de aplicar un metodo basado en la evaluacion de la razon Re/Os. Despues de haber deducido experimentalmente una razon basica 187Os : 186Os, los autores examinan la cuestion de las edades minimas. Estas varian sensiblemente y estan al parecer comprendidas entre 3,7 y 5,6 x 109 anos. (author)

Abstract (Russian)

Pri pomoshchi massovoj spektrometrii byl izuchen izotopnyj sostav bol'shogo chisla prob osmiya zemnykh platinovykh rud i zheleznykh meteoritov. Poluchennoe sootnoshenie mezhdu izotopami osmiya-187 i osmiya-186 v rudakh osmiya i zheleza i v probakh osmiya, kolichestvenno, izvlechennykh iz zheleznykh meteoritov, izmenyaetsya v predelakh ot 0,88 do 1,41. EHti izmeneniya mogut byt' obyasneny obrazovaniem radiogennogo osmiya vsled za raspadom reniya-187, yavlya- yushchegosya prirodnym beta-izluchatelem s naibolee nizkoj izvestnoj beta-ehnergiej. Aktiva- tsionnyj analiz pri pomoshchi nejtronov dokazyvaet, chto renij i osmij yavlyayutsya obshchimi ehlementami zheleznykh meteoritov, soderzhashchimisya v nikh v nichtozhnykh kolichestvakh. Tak kak opredelenie vozrasta ehtikh tel obychnymi metodami predstavlyaet ochen' bol'shie zatrudneniya, byl izuchen metod ispol'zovaniya reniya/osmiya. Iz nashikh issledovanij bylo vyvedeno preobladayushchee sootnoshenie mezhdu osmiem-187 i osmiem-186; obsuzhdaetsya ikh ''minimal'nyj vozrast''. EHtot vozrast izmenyaetsya v znachitel'nykh predelakh i veroyatno zaklyuchaetsya v intervale ot 3,7-109 do 5,6-109 let. (author)
Part of:
Radioisotopes in the Physical Sciences and Industry. Proceedings of the Conference on the Use of Radioisotopes in the Physical Sciences and Industry. V. 1

Additional details

Additional titles

Original title (English)
Anomalies dans l'abondance isotopique de l'osmium-187 dans l'osmium terrestre et meteoritique - Essai de determination de l'age des meteorites de fer au moyen du rapport Re/Os; Anomalii v rasprostranennosti izotopa osmiya-187 v zemnom i meteoritnom osmie i popytka opredeleniya vozrastov reniya/osmiya v zheleznykh meteoritakh; Anomalias en la abundancia isotopica del

Publishing Information

Publisher
Globus, Druck- und Verlagsanstalt
Imprint Place
Vienna (International Atomic Energy Agency (IAEA))
Imprint Title
Radioisotopes in the Physical Sciences and Industry. Proceedings of the Conference on the Use of Radioisotopes in the Physical Sciences and Industry. V. 1
Imprint Pagination
556 p.
Series
Proceedings Series
Journal Page Range
p. 29-36
ISSN
0074-1884

Conference

Title
Conference on the Use of Radioisotopes in the Physical Sciences and Industry
Dates
6-17 Sep 1960
Place
Copenhagen (Denmark)

INIS

Country of Publication
International Atomic Energy Agency (IAEA)
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
43112904
Subject category
S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
Resource subtype / Literary indicator
Conference
Descriptors DEI
ABUNDANCE; IRON METEORITES; ISOTOPE RATIO; MASS SPECTROSCOPY; NEUTRON ACTIVATION ANALYSIS; ORES; OSMIUM; OSMIUM 186; OSMIUM 187; PLATINUM; RHENIUM 187; TRACE AMOUNTS
Descriptors DEC
ACTIVATION ANALYSIS; ALPHA DECAY RADIOISOTOPES; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CHEMICAL ANALYSIS; DIMENSIONLESS NUMBERS; ELEMENTS; EVEN-EVEN NUCLEI; EVEN-ODD NUCLEI; HEAVY NUCLEI; ISOTOPES; METALS; METEORITES; NONDESTRUCTIVE ANALYSIS; NUCLEI; ODD-EVEN NUCLEI; OSMIUM ISOTOPES; PLATINUM METALS; RADIOISOTOPES; REFRACTORY METALS; RHENIUM ISOTOPES; SPECTROSCOPY; STABLE ISOTOPES; TRANSITION ELEMENTS; YEARS LIVING RADIOISOTOPES

Optional Information

Notes
3 figs, 3 tabs, 18 refs Imprint:3 figs, 3 tabs, 18 refs
Secondary number(s)
STI/PUB--20(Vol.1)