首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Primitive ultrafine matrix in ordinary chondrites
Authors:ER Rambaldi  BJ Fredriksson  K Fredriksson
Institution:1. Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90024 U.S.A.;2. Department of Mineral Sciences, Smithsonian Institution, Washington, DC 20560 U.S.A.
Abstract:Ultrafine matrix material has been concentrated by sieving and filtering disaggregated samples of six ordinary chondrites of different classes. This component(s), “Holy Smoke” (HS), is enriched in both volatile, e.g. Na, K, Zn, Sb, and Pb, as well as refractory elements, e.g. W and REE; however, the element ratios vary greatly among the different chondrites. SEM studies show that HS contains fragile crystals, differing in composition, and apparently in gross disequilibrium not only among themselves but also with the major mineral phases and consequently thermodynamic equilibration did not occur. Thus HS must have originated from impacting bodies and/or was inherent in the “primitive” regolith. Subsequent impact brecciation and reheating appears to have altered, to varying degrees, the original composition of this ultrafine matrix material. Recent “cosmic dust” studies may indicate that HS still exists in the solar system. Survival of such delicate material must be considered in all theories for the origin of chondrites.
Keywords:
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号