Argon-Argon Dating
Argon-argon (40Ar/39Ar) dating is the modern, high-precision successor to conventional potassium-argon dating, in which the parent potassium is measured indirectly by converting it to a measurable argon isotope inside a nuclear reactor. A potassium-bearing sample is irradiated so that potassium-39 transmutes into argon-39, which then stands as a proxy for the parent potassium; both the radiogenic argon-40 daughter and this argon-39 proxy can be measured on the same aliquot by a single mass spectrometer, eliminating the sample-heterogeneity problem of the older method. Crucially, the gas can be released either by fusing a single crystal with a laser or by heating the sample in incremental steps, the latter producing an age spectrum that reveals argon loss, excess argon, and disturbance. Synthesized in McDougall and Harrison's monograph, the technique delivers the precise, internally checkable ages now standard for dating volcanic deposits at hominin and Palaeolithic sites.
源记录
引文逐字复制自方法源记录。这些引文不代表任何层级的验证。
- McDougall, I., & Harrison, T. M. (1999). Geochronology and Thermochronology by the 40Ar/39Ar Method (2nd ed.). Oxford University Press. · ISBN 9780195109207
精选声明
声明已持久化到证据分类账中，每个声明都有自己的评估。
当分类账中没有声明时，此视图不会自行创建声明评估。
相关方法
从方法图中生成，显示为机器建议的关系 — 不推断任何证据声明。