PRIMORDIAL ARGON AND NEON IN CARBONACEOUS CHRONDITES AND UREILITES
Journal Article
·
· Geochim. et Cosmochim. Acta
The abundance and isotopic composition of Ar and Ne in five carbonaceous chondrites and in two ureilites were measured. The results show that these meteorites contain large amounts ot trapped primordial gases. Heating experiments with only partial extraction of the rare gases were carried out, showing that at 950 deg K the radiogenic Ar diffuses out more readlly than the primordial Ar, and cosmo genic Ne at about the same rate as primordial Ne. From that it is concluded that the primordial gases are enclosed within the matrix of the crystal lattice. Argon--potassium ages and Ne/sup 2//sup 1/ exposure ages were calculated. Both are affected by diffusive losses. Only Felix has an A/K age of 4.5 AE (billion years). A large loss of primordial Ar and Ne as compared to the Si is observed. The loss of primordial Ar is constant within a factor 10 for all samples, and about 10 to 100 times smaller than the loss observed for the earth. The ratios of primordial Ne/sup 2//sup /0 to primordial Ar/sup 3//sup 6/ have values between 0.005 and 22, indicating large fractionation between Ar and Ne as compared to the corresponding cosmic ratio. Fractionation by diffusive losses is discussed. Some deviations of the isotopic ratios of primordial Ar and Ne from the atmospheric ratios are observed. (auth)
- Research Organization:
- Univ. of California, La Jolla
- NSA Number:
- NSA-15-022541
- OSTI ID:
- 4045941
- Journal Information:
- Geochim. et Cosmochim. Acta, Journal Name: Geochim. et Cosmochim. Acta Vol. Vol: 24: Nos. 1/2
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
COSMOGENIC ARGON AND NEON IN STONE METEORITES
RARE GASES IN THE CHONDRITE PANTAR
ON THE PRIMORDIAL GASES IN THE KAPOETA AND STAROE PESJANOE CHRONDRITES
Journal Article
·
Mon May 01 00:00:00 EDT 1961
· J. Geophys. Research
·
OSTI ID:4010403
RARE GASES IN THE CHONDRITE PANTAR
Journal Article
·
Tue May 01 00:00:00 EDT 1962
· J. Geophys. Research
·
OSTI ID:4830389
ON THE PRIMORDIAL GASES IN THE KAPOETA AND STAROE PESJANOE CHRONDRITES
Journal Article
·
Fri Jun 01 00:00:00 EDT 1962
· Geochimica et Cosmochimica Acta
·
OSTI ID:4791800