On the chondrite—achondrite transition: mineralogy and chemistry of Yamato 74160 (LL7) |
| |
| Authors: | Hiroshi Takeda Ted J Huston Michael E Lipschutz |
| |
| Institution: | 1. Mineralogical Institute, Faculty of Science, University of Tokyo, Hongo, Tokyo 113 Japan;2. Department of Chemistry, Purdue University West Lafayette, IN 47907 U.S.A. |
| |
| Abstract: | We report on the petrology, mineralogic properties and contents of major elements and trace elements Ag, Au, Bi, Cd, Co, Cs, Ga, In, Rb, Se, Te, Tl, U and Zn (determined by radiochemical neutron activation analysis) in Yamato 74160, interpreted as an LL7 chondrite. All properties are consistent with this meteorite having been recrystallized and partially melted locally once at temperatures well above 1090°C under conditions such that some minerals (e.g. plagioclase, euhedral pyroxene, tetrataenite) grew from melt pockets and siderophilic and chalcophilic elements were lost by extraction into eutectic melt that drained away. Inhomogeneous plagioclase compositions and mobile element loss suggest shock as the most likely heat source. Yamato 74160, while inferentially chondritic, is a larval achondrite: even higher temperatures and longer times would have been required to cause the separations necessary to transform it to an identifiable achondrite type. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
