The notion of remote element synthesis has recently been modified to explain the presence of nucleogenetic isotopic anomalies and decay products of short-lived nuclides by injection of a small amount of exotic nucleogenetic material. Even with this modification, remote element synthesis seems inconsistent with the following observations: Evidence of coupled variations in the chemical and isotopic compositions of the source material for meteorites. Residual coupling of chemical and isotopic heterogeneities across planetary distances in the solar system today. The mass-fractionation relationship seen across isotopes of elements in the planetary system, in the solar wind, and in solar flares. Linkage of short-lived radioactivities with isotopic anomalies and with physical properties of their host grains, as expected for early condensate of fresh stellar debris. Temporal and spatial distributions of short-lived nuclides and their decay products. Mirror-image (+ and -) isotopic anomalies in meteorite grains that sum to 'normal' isotopic ratios, as expected of unmixed products of the same nuclear reactions that produced our bulk elements. The lack of supporting evidence for 'presolar' grains or nearby stars that injected exotic material into the early solar nebula.



Keywords and Phrases

Chemical Composition; Isotopic Composition; Meteorite; Radionuclide; Solar System; Element Synthesis; Planets

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version

Final Version

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© 2000 Indian Academy of Sciences, All rights reserved.

Publication Date

01 Mar 2000

Included in

Chemistry Commons