Carbonaceous Chondrite Clast Captured in Collision Event by the Elga Iron Meteorite (Group IIE)

A melt pocket (MP) found in only one of the silicate inclusions in the Elga iron meteorite was studied using TEM, SEM, EMPA, and Raman spectroscopy methods. The MP demonstrates the liquid immiscibility of the FeCO₃–Fe₃(PO₄)₂–SiO₂–(Fe, Ni)₃P melts, the mineralogical and bulk chemical composition of which is inconsistent with that of the silicate inclusions in the Elga meteorite. Key differences include: (1) The high content of Fe oxide in the MP is inconsistent with the low FeO content (≈3 wt %) in the SiO₂ glass of silicate inclusions; (2) Ca and Mg, the main phase-forming cations of silicate inclusions, are absent in the MP; (3) Siderite and sarcopside, the main oxygen-bearing phases in the MP, were not found in other silicate inclusions of Elga; (4) carbon compounds (aromatized sp² carbon, phenols) identified in the MP were not found in the host silicate substance. These contradictions lead to the conclusion that the melt pocket is a melted fragment of carbonaceous chondrite captured by Elga’s parent body during a collision with carbonaceous asteroid.