A New Calculation for the Age of the Earth from Abundances of Lead Isotopes

Ostic, R. G.; Russell, Rick; Reynolds, P. H.

doi:10.1038/1991150a0

Cited by 37 publications

(2 citation statements)

References 6 publications

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“…Numerous authors of the period presented similar primary terrestrial growth curves, but all used the same basic data set, differing in only a few details, and came to the same basic conclusion that, to a first approximation, the source of ordinary leads has behaved as a single-stage system since formation of the Earth at approximately 4.55Ga (e.g. Russell & Farquhar 1960;Ostic et al 1963Ostic et al , 1967Russell & Reynolds, 1965;Kanasewich 1968;Cooper et al 1969;Stacey et al 1969;Doe 1970;Russell 1972).…”

Section: The Primary Terrestrial Growth Curvementioning

confidence: 99%

The Age of the Earth in the Twentieth Century

Yochelson¹,

Brush

1989

Earth Sciences History

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At the end of the nineteenth century, Lord Kelvin's upper limit of only 20 or 30 million years for the age of the Earth was challenged by the American geologist T. C. Chamberlin, who showed that Kelvin's model of an Earth gradually cooling from an initial molten state was not the only possible one. Kelvin's limit was soon afterwards repealed by the new science of radioactivity, which yielded ages of a few billion years. While some geologists resisted this expanded time-scale, Chamberlin was the only one who could provide a comprehensive cosmogonical theory that did not submit to the epistemological superiority of physics and astronomy. In the 1940s, as radiometric age determinations improved in accuracy, they came into conflict with the expanding-universe cosmology — a conflict which the cosmologists eventually avoided by expanding their distance and time scales. In 1953, Patterson announced the result 4.5 billion years, which is still accepted as the best estimate for the age of the Earth. But geologists, liberated from Kelvin's limit, define the epoch of the Earth's formation as being outside the scope of their science, and their textbooks rarely give credit to the person who established the number that once seemed so important to accounts of the Earth's history.

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Section: The Primary Terrestrial Growth Curvementioning

confidence: 99%

The Age of the Earth in the Twentieth Century

Yochelson¹,

Brush

1989

Earth Sciences History

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“…It falls neatly in the middle of the upper group, being slightly less radiogenic than the Tui Mine lead, and is probably therefore yet another example of a suite of leads of widely variable isotopic composition. As such it would be a quite unsatisfactory member of a set of points to be used in developing a fundamental lead isotope growth curve in the manner suggested by OsTic et al (1963) and RusSELL and REYNOLDS (1965). For similar reasons all the young galena samples, including the least radiogenic Tui Mine measurements, would also be unsuitable for such single-stage model calculations.…”

Section: Regionmentioning

confidence: 99%

Lead isotope measurements on volcanics and associated galenas from the Coromandel - Te Aroha region, New Zealand

Cooper

Richards

1969

Geochem. J.

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Isotopic measurements have been made on lead extracted from samples of andesite, propylitized andesite and rhyolite, and from galenas present in quartz-calcite veins occurring in the Miocene Hauraki Goldfield region, New Zealand. Measurement bias due to isotopic fractionation has been removed by the double-spike technique. All samples show varying degrees of J-type anomaly. Although there is some overlap, the galena samples generally appear more anomalous than the andesites; lead in the veins is isotopically different from lead in adjacent andesite. There is no evidence of contamination by ancient, low radiogenic rock systems, or of isotopic fractionation during vein formation. Although the vein galenas may be slightly enriched in preferential ly-extracted radiogenic lead, the results are thought to represent isotopic inhomogeneity in the sources. With one exception the vein galena, rhyolite, propylitized andesite, and hydrother mally altered rocks form a linearly-distributed set on the 208Pb/2o4Pb _ 206Pb/2o4Pb dia gram, which appears to be distinct from the unaltered andesite. A similar but less distinct trend is present on the 207Pb/204Pb _ 206pb/2o4Pb diagram. It is suggested that the vein galenas and rhyolites, together with the propylitization and hydrothermal fluids, could all have originated from the one bulk source-material, the thick Mesozoic greywacke-argillite sequence, and that the andesites have come from another, necessarily deeper source. Propylitization processes appear to have introduced the hydrothermal-rhyolite-galena-type lead into the altered andesites. A criticism is made of the use of lead isotope results from hydrothermal material as input data for the calculation of single-stage model growth-curves.

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