Isotopic signatures as tools to reconstruct the primordial architecture of the Solar System

Jan Render, Gregory A. Brennecka

Earth and Planetary Science Letters
Available online 10 December 2020



• Angrites and eucrites exhibit nucleosynthetic anomalies in Nd and Zr isotopes.
• These isotopic signatures are consistent with deficits in s-process nuclides.
• This is similar to previously reported deficits for chondritic meteorites.
• Distribution of s-process matter could be linked to heliocentric distance.
• This creates potential for ‘cosmolocating’ feeding zones of Solar System materials.”

“The significant reorganization of the early Solar System due to giant planet migration has hampered our understanding of where planetary bodies formed. Previously employed proxies for reconstructing the primordial planetary architecture, such as water content or oxidation state, are complicated by post-accretionary processes. Here we investigate basaltic achondrites for their nucleosynthetic isotope signatures in the elements neodymium (Nd) and zirconium (Zr) and show that they are—similar to previously investigated chondritic meteorites—characterized by a relative deficit in isotopes produced by the s-process of nucleosynthesis. Importantly, these data are well correlated with nucleosynthetic signatures observed in other elements, demonstrating that s-process matter was heterogeneously distributed throughout the early Solar System. By comparing these isotopic signatures with potential proxies for Solar System reconstruction and computer modeling, we here argue that this isotopic heterogeneity in bulk meteoritic materials is linked to the original heliocentric distance of formation. Such scaling of nucleosynthetic signatures with heliocentric distance could permit reconstruction of the primordial architecture of the Solar System by ‘cosmolocating’ the accretion orbits of meteoritic parent bodies as a function of incorporated s-process matter.”