Trapped noble gases in unequilibrated ordinary chondrites

摘要: The abundances and isotopic compositions of noble gases were determined in bulk samples acid-resistant residues eight unequilibrated (type 3.0-3.8) ordinary chondrites (two LLs; four Ls, with two from a paired fall; Hs) including the most primitive one, Semarkona. HL-Xe was found all cases except Dhajala (H 3.8). H-part is isotopically indistinguishable that Allende; same they find true for ratio H-Xe/L-Xe. Thus, their data do not confirm previous reports variations this among nor any different Allende. Constraints on origin as well trapping mechanism are discussed. Also present meteorites an HF/HCl soluble component high Ar/Xe ratio. both Xe correlate petrological subtype. Combustion residue yielded Ne abundance ratios {sup 20}Ne/{sup 22}Ne = 10.1 {plus minus} 0.2 21}Ne/{sup {le} 0.04 part (Q-Ne) which associated (ordinary) heavy gases. released experiment weremore » combustion only minor portion C; highest 132}Xe/C atom 1.3 {times} 10{sup {minus}8} first step 10 times lower than solar In Semarkona (LL 3.0) there evidence presence Ne-E; ALH A 77278 about half (SEP-Ne).« less