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High precision oxygen three‐isotope analyses of anhydrous chondritic interplanetary dust particles
Author(s) -
NAKASHIMA Daisuke,
USHIKUBO Takayuki,
ZOLENSKY Michael E.,
KITA Noriko T.
Publication year - 2012
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2011.01319.x
Subject(s) - anhydrous , interplanetary dust cloud , isotopes of oxygen , chondrite , chondrule , comet , silicate , meteorite , carbonaceous chondrite , astrobiology , chemistry , mineralogy , geology , analytical chemistry (journal) , geochemistry , environmental chemistry , physics , solar system , organic chemistry
– Oxygen three‐isotope ratios of three anhydrous chondritic interplanetary dust particles (IDPs) were analyzed using an ion microprobe with a 2 μm small beam. The three anhydrous IDPs show Δ 17 O values ranging from −5‰ to +1‰, which overlap with those of ferromagnesian silicate particles from comet Wild 2 and anhydrous porous IDPs. For the first time, internal oxygen isotope heterogeneity was resolved in two IDPs at the level of a few per mil in Δ 17 O values. Anhydrous IDPs are loose aggregates of fine‐grained silicates (≤3 μm in this study), with only a few coarse‐grained silicates (2–20 μm in this study). On the other hand, Wild 2 particles analyzed so far show relatively coarse‐grained (≥ few μm) igneous textures. If anhydrous IDPs represent fine‐grained particles from comets, the similar Δ 17 O values between anhydrous IDPs and Wild 2 particles may imply that oxygen isotope ratios in cometary crystalline silicates are similar, independent of crystal sizes and their textures. The range of Δ 17 O values of the three anhydrous IDPs overlaps also with that of chondrules in carbonaceous chondrites, suggesting a genetic link between cometary dust particles (Wild 2 particles and most anhydrous IDPs) and carbonaceous chondrite chondrules.