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The Kaidun meteorite: Composition and origin of inclusions in the metal of an enstatite chondrite clast
Author(s) -
IVANOV Andrei V.,
MACPHERSON Glenn J.,
ZOLENSKY Michael E.,
KOKOVA Nataliya N.,
MIGDISOVA Lyudmila F.
Publication year - 1996
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.1945-5100.1996.tb02034.x
Subject(s) - enstatite , meteorite , chondrite , geology , metal , mineralogy , kamacite , geochemistry , materials science , astrobiology , metallurgy , physics
— Metal nodules are one of the major textural components of Kaidun sample #01.3.06 EH3‐4. In terms of structure, the nodules are of three types: (1) globular, (2) zoned with a massive core and globular mantle, and (3) nodules with no internal structure. The size and composition of the globules in the nodules and grains of metal of the matrix are almost identical: no greater than 20 μm and Ni, 5.95; Si, 3.33 wt%. The nodules contain small (usually <5 μm) inclusions of SiO 2 ; albitic glass; enstatite; roedderite; and a mixture of SiO 2 and Na 2 S 2 . This is the first reported occurrence of a simple sulfide of an alkaline metal in nature. The formation of the inclusions appears to be related to condensation of material onto the surfaces of metal grains. The nodules appear to have formed by aggregation of separate grains (globules) of metal, with conservation of condensates on the grain surfaces as inclusions. The inclusions probably condensed over a significant temperature range from 1400 to 600 K. The aggregation of metal grains and formation of the nodules probably occurred simultaneously with condensation.