Case study of chondrule alteration with IR spectroscopy in NWA 2086 CV3 meteorite

摘要: Abstract Analyzing the alteration in an olivine chondrule of NWA 2086 CV3 meteorite, infrared spectral, electron microprobe and optical microscopic observations were correlated to each other. The intensity wavelength positions peaks changed characteristically with progression related Fe/Mg substitution inward chondrule. Moderate good correlations identified between Fo% composition 830 860 cm−1 IR peaks. disappearance 1020 cm−1 peak by structural change happens already at a low level without changing appearance mineral. existence 980 cm−1 is found be indicator intact phase olivine. While profiles perpendicular chondrule׳s perimeter showed that progressed 15–20 μm distance observable fractures (probablly some diffusion process), “alteration distance” from various obvious inside was only 3–5 μm distance. These suggest more effective close matrix, also fluids although able circulate along large internal too, did not produce such strong there, like what happened matrix. It demonstrated poorly exploited contact mode ATR based reflection method spectroscopy provide useful tool analyze micrometer scale much sample preparation, enable identifying alterations where olivines still look optically intact.