Thermal Processing History of the Solar System’s First Solids Inferred from Isotope Fractionation of Refractory ElementsOPEN ACCESS 

· by · in , , , ,

Yankun Di, François L. H. Tissot, Qing-Zhu Yin, Christopher Mornement, Trevor R. Ireland, and Yuri Amelin

The Astrophysical Journal, Volume 1002, Number 1, Published: 21 April 2026

LINK (OPEN ACCESS)
PDF (OPEN ACCESS)

“We present analyses of mass-dependent isotope fractionation of strontium (Sr) and neodymium (Nd) from a number of petrologically and chemically diverse calcium–aluminium-rich inclusions (CAIs) from the CV chondrite Allende. Combined with literature data, our results reveal systematic variations of elemental and isotopic fractionation signatures that depend on element volatility and CAI type. In most CAIs with little volatility-driven elemental fractionation (which we collectively refer to as “nongroup-II” CAIs), moderately refractory elements such as Nd and Ti are not isotopically fractionated relative to chondrites, while less refractory elements such as Sr and Ca show light isotope enrichments correlated with their lowered abundances. In contrast, in CAIs with the “group-II” type elemental fractionation pattern, refractory elements show more variable isotopic compositions uncorrelated to element abundances. The coupled elemental and isotopic fractionation in nongroup-II CAIs are consistent with a simple evaporation–condensation–reevaporation origin in the solar nebula, while group-II CAIs require more extensive and complex thermal processing histories. The disparate thermal evolutions of group-II and nongroup-II CAIs indicate distinct physical conditions in their formation pathways, corresponding to different localities in the protoplanetary disk. Nongroup-II CAIs may represent materials that were more effectively transported between high-temperature and low-temperature disk zones and thus experienced more intensive heating and cooling, while group-II CAIs represent particles that more frequently traversed between those zones but were neither heated nor cooled as thoroughly as the former.”

Related posts (automatically generated):

  1. Radial transport and nebular thermal processing of millimeter-sized solids in the Solar protoplanetary disk inferred from Cr-Ti-O isotope systematics of chondrulesOPEN ACCESS 
  2. Protracted Timescales for Nebular Processing of First-formed Solids in the Solar SystemOPEN ACCESS 
  3. The Evolution of the Protoplanetary Disk Recorded by Nucleosynthetic Isotope Variations of Variable Stellar Origin in Refractory Inclusions
  4. Calcium isotope evidence for the formation of early condensates in the Solar System from unmixed reservoirs with distinct nucleosynthetic originsOPEN ACCESS 
  5. Strontium isotope evidence for the repeated formation of refractory inclusions in the Allende meteorite
  6. Chondritic ingredients: II. Reconstructing early solar system history via refractory lithophile trace elements in individual objects of the Leoville CV3 chondrite
  7. Calcium-aluminum-rich inclusions with fractionation and unidentified nuclear effects (FUN CAIs): II. Heterogeneities of magnesium isotopes and 26Al in the early Solar System inferred from in situ high-precision magnesium-isotope measurements
  8. Ultra-refractory metal assemblages in calcium-aluminum-rich inclusions: Probes of the inner solar protoplanetary disk
  9. Uniform initial 10Be/9Be inferred from refractory inclusions in CV3, CO3, CR2, and CH/CB chondrites
  10. Combined mass-dependent and nucleosynthetic isotope variations in refractory inclusions and their mineral separates to determine their original Fe isotope compositions
Tags: , , , , , ,