Sulfur abundances and isotopic compositions in bulk carbonaceous chondrites and insoluble organic material: Clues to elemental and isotopic fractionations of volatile chalcophiles

Abstract

The bulk S elemental abundances and δ 34 S values for 83 carbonaceous chondrites (mostly CMs and CRs) and Semarkona (LL3.0) are reported. In addition, the S elemental abundances and δ 34 S values of insoluble organic material (IOM) isolated from 25 carbonaceous chondrites (CMs, CRs, and three ungrouped) are presented. The IOM only contributes 2-7% of the S to the bulk meteorites analyzed and exhibits no systematic variations. The average group bulk S abundances are similar to previous measurements. Ingroup variations likely reflect variations in matrix abundances, as well as parent body processes and weathering. The S and C abundances are roughly correlated and scatter about a mixing line between CI-like matrix and C-free and S-depleted chondrules. Systematic deviations from this mixing line may indicate different degrees of heating of matrix material in the nebula. There are no systematic variations in average group δ 34 S values, in contrast to what is seen for the volatile chalcophiles Zn, Te, Se, and Ag, as well as the less volatile siderophile Cu. Renormalization of the elemental and isotopic compositions indicates that the elemental and isotopic fractionations of Zn, Te, and Ag were controlled by the same process, whereas Se is intermediate in its behavior between these three elements and S. The isotopic fractionations could be associated with diffusion of volatile chalcophiles into sulfide at the end of chondrule formation. Copper appears to be distinct in its behavior from the chalcophiles, perhaps because it is more refractory and more siderophile.

Primordial aqueous alteration recorded in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu

“…The isotopic profiles of ΣSOM from the sequential extractions are shown in Table S4 . Please see the IOM treatment 34 and C-N-S isotopic variations of the Solar System 6 , 36 , 79 , 80 . …”

Chemical evolution of primordial salts and organic sulfur molecules in the asteroid 162173 Ryugu

“… A Total sulfur content (wt%) and isotopic profiles of the Ryugu samples (A0106, C0107) and of representative carbonaceous groups (CI, CM, CO, CR, and CV). Sulfur (S, wt%) and δ 34 S (‰ vs. VCDT) values are from the literature 4 , 17 , 47 and references therein. Error bars are one standard deviation (1 SD) values of multiple particles.…”

Evidence of both molecular cloud and fluid chemistry in Ryugu regolith

“…We acquired similar data from two other CC meteorites, CM2 Murchison and CR2 Graves Nunataks (GRA) 95229 to compare the distribution of the sulfur oxidation states. The total sulfur abundance in Ryugu particles (3.3 to 5.5 wt %) ( 6) is higher compared to that reported in Murchison and GRA 95229 (1.2 to 3.3 wt %) (21). Data and discussion on the meteorites are in the Supplementary Materials.…”