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Cameron, A.G.W., 1962: The Early Chronology of the Solar System. NASA TN D-1465. National Aeronautics and Space Administration.
The solar system's early history can be deduced from a study of anomalies in the isotopic composition of certain elements extracted from meteorites. In stone meteorites, xenon is sometimes in enriched in Xe129; and in iron meteorites, silver is sometimes enriched in Ag107. If these anomalies are attributed to the decay of the extinct radioactives of I129 and Pd107, then it is possible to deduce the approximate time intervals between the cessation of nucleosynthesis in the interstellar gas, and the formation and cooling of the meteorite parent bodies to the point where further fractionation of the elements involvded ceases. This time intervalis about 1.5×108 years for the xenon anomaly and about 2 to 4×107 years for the silver anomaly. The earth's atmosphere contains xenon that has been subjected to additional enrichment processes; the earth apparently did not start retaining any xenon until about 108 years following the retention of xenon by the meteorites.
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