TY - JOUR
T1 - High precision oxygen three-isotope analyses of anhydrous chondritic interplanetary dust particles
AU - Nakashima, Daisuke
AU - Ushikubo, Takayuki
AU - Zolensky, Michael E.
AU - Kita, Noriko T.
PY - 2012/2
Y1 - 2012/2
N2 - Oxygen three-isotope ratios of three anhydrous chondritic interplanetary dust particles (IDPs) were analyzed using an ion microprobe with a 2μm small beam. The three anhydrous IDPs show Δ 17O 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 17O values. Anhydrous IDPs are loose aggregates of fine-grained silicates (≤3μm in this study), with only a few coarse-grained silicates (2-20μm 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 17O 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 17O 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.
AB - Oxygen three-isotope ratios of three anhydrous chondritic interplanetary dust particles (IDPs) were analyzed using an ion microprobe with a 2μm small beam. The three anhydrous IDPs show Δ 17O 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 17O values. Anhydrous IDPs are loose aggregates of fine-grained silicates (≤3μm in this study), with only a few coarse-grained silicates (2-20μm 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 17O 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 17O 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.
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U2 - 10.1111/j.1945-5100.2011.01319.x
DO - 10.1111/j.1945-5100.2011.01319.x
M3 - Article
AN - SCOPUS:84856751383
SN - 1086-9379
VL - 47
SP - 197
EP - 208
JO - Meteoritics and Planetary Science
JF - Meteoritics and Planetary Science
IS - 2
ER -