Trace Element Composition of Silicate Minerals in the Chondrules and Matrix of the Buschhof Meteorite

Abstract

The paper presents results of SIMS and SEM-EDS studies of the silicate minerals from one radial and one granular chondrule of the Buschhof ordinary equilibrated L6 chondrite and discusses geochemical features of the olivine, pyroxene, and plagioclase from the chondrules and matrix of this meteorite. Results show that pyroxene and plagioclase from the radial chondrule did not preserve the chondritic Ca/Al and Y/Ho ratios and positive correlation between La and Yb. Olivine from the granular chondrule has no traces of cosmochemical fractionation. The fact that chondritic element ratios preserve in the silicates of the granular chondrule indicates chondrule formation by the melting of refractory chondrule precursors. Both chondrules show evidence of interaction with the nebular gas and thermal metamorphism. The differences in the concentrations of trace elements in minerals of the chondrules and matrix reflect the rapid cooling of the silicate phases from the central part of the chondrule toward the meteorite matrix.