Synchrotron Radiation XRD Analysis of Indialite in Y-82094 Ungrouped Carbonaceous ChondriteY-82094 is an ungrouped type 3.2 carbonaceous chondrite, with abundant chondrules making 78 vol.% of the rock. Among these chondrules, an unusual porphyritic Al-rich magnesian chondrule is reported that consists of a cordierite-like phase, Al-rich orthopyroxene, cristobalite, and spinel surrounded by an anorthitic mesostasis. The reported chemical formula of the cordierite-like phase is Na(0.19)Mg(1.95)Fe(0.02)Al(3.66)Si(5.19)O18, which is close to stoichiometric cordierite (Mg2Al3[AlSi5O18]). Although cordierite can be present in Al-rich chondrules, it has a high temperature polymorph (indialite) and it is therefore necessary to determine whether it is cordierite or indialite in order to better constrain its formation conditions. In this abstract we report on our synchrotron radiation X-ray diffraction (SR-XRD) study of the cordierite-like phase in Y-82094.
Document ID
20160002404
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Mikouchi, T. (Tokai Univ. Tokyo, Japan)
Hagiya, K. (Hyogo Univ. Hyogo, Japan)
Sawa, N. (Hyogo Univ. Hyogo, Japan)
Kimura, M. (Ibaraki Univ. Mito, Japan)
Ohsumi, K. (Japan Synchrotron Research Inst. Hyogo, Japan)
Komatsu, M. (Waseda Univ. Tokyo, Japan)
Zolensky, M. (NASA Johnson Space Center Houston, TX, United States)