QUANTITATIVE MICRO-PIXE ANALYSIS OF YANZHUANG METEORITE

Yanzhuang H-6 chondrite is the most heavily shocked, severely reheated , partly melted and recrystallized meteorite formed in the environment of microgravity, high vacuum and ultralow temperature of the space. I t is consequently the most valuable specimen for microgravity research on the mechanism of crystallization of FeNi alloy in space. Based on SEM and EPMA studies, the distributions of major and trace elements in FeNi-FeS blobs were analysed quantitatively by a scanning proton micr oprobe with TTSPM software package. The results of Fe and Ni mapping s how the core-crust microstructure of FeNi metal dendrites, identical w ith the SEM analysis. The quantitative analysis of the concentrations of the core and the crust of FeNi dendrites supports the view of that these dendrites formed after fast cooling under ultralow temperature a nd microgravity. The distributions of some trace elements provide new valuable information for revealing the forming mechanism of FeNi alloy in space.