THE ISOTOPIC COMPOSITIONS AND CONCENTRATIONS OF LEAD IN SOME CHONDRITIC STONE METEORITES

Journal Article · Tue Nov 01 04:00:00 EST 1960 · Geochim. et Cosmochim. Acta

DOI:https://doi.org/10.1016/0016-7037(60)90079-X· OSTI ID:4092902

Hess, D C; Marshall, R R

Microgram quantities of lead were volatilized from the chondrites and purified for mass spectrometric analysis. Aliquots of approximately 1 mu g were surface-ionized by use of the boric acid technique. The isotopic compositions found range from highly radiogenic lead, in the case of Richardton, to leads in the other three chondrites that are substantially less radiogenic than average lead in the crust of the earth. From recent concentration determinations by the isotopic dilution method, it seems that the amount of lead in Beardsley is about 0.13 ppm and that in Richardton about 0.06 ppm. The leads in these meteorites are consistent within a factor of approximately 2 with the lead--lead ages and the independently measured uranium and thorium concentrations. The lead--lead age for Richardton is the same as that found by Patterson (1955) for Nuevo Laredo, being 4.6 aeons. The lead concentration measured for Forest City is 0.09 ppm, whereas that for Holbrook is 0.28 ppm. Holbrook is quite anomalous in containing 2.5 times the amount of radiogenic lead that can be explained by the accumulation of decay products in situ with a primeval lead that had the isotopic composition of the lead from the troilite in the Canyon Diablo and Henbury iron meteorites. The total amount of lead on the surface of a meteorite appears to be comparable to the total amount inside. The isotopic composition of this surface lead indicates that it is principally terrestrial lead. (auth)

• Research Organization: Argonne National Labs., Ill.
• NSA Number: NSA-15-005218
• OSTI ID: 4092902
• Journal Information: Geochim. et Cosmochim. Acta, Journal Name: Geochim. et Cosmochim. Acta Vol. Vol: 20
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AGE ESTIMATION
BOROHYDRIDES
DECAY
DISTRIBUTION
EARTH
EVAPORATION
GEOLOGY, MINERALOGY, AND METEOROLOGY
IMPURITIES
IONIZATION
IRON SULFIDES
LEAD
LEAD ISOTOPES
MASS SPECTROMETERS
METEORITES
MINERALS
NUEVO LAREDO METEORITE
QUANTITATIVE ANALYSIS
QUANTITY RATIO
SAMPLING
SOLUTIONS
SURFACES
THORIUM
TROILITE
URANIUM