Pleonaste in Boxian meteorite

Abstract

There are three kinds of occurrence of pleonaste, a rare meteoritic mineral, totally found in Boxian meteorite. They are as the following: (i) occurring in the inner circle of the chondrule edge, of which a circle texture is composed; (ii) occurring in the state of inclusions, included in an olivine chondrule, with close paragenesis of wadsleyite; (iii) occurring in the state of porphyry. The chondrule in the first occurrence belongs to CA chondrules. The chemical compositions of pleonaste are heterogeneity except for the atomic ratios of Fe/(Mg+ Fe), which can be attributed to the following reasons: (i) they are congenetic minerals; (ii) the heterogeneity of the compositions of the solar clouds in the early states; (iii) the chondrites are the multiple-stage evolution; (iv) the further proof of Boxian meteorite is an unequilibrium common chondrite.