Petrography of the Baszkówka chondrite

Abstract

The Baszkówka chondrite comprises chondrules, individual crystals of olivine, xenomorphic concentrations of kamacite and troilite, matrix and pores up to 3.0 mm in diameter; porosity reaches 20% by volume. Measurements of 697 chondrules in an area of 250 m2 enabled distinction of three populations. The chondrules and olivine crystals have been sintered at high temperatures. Six structural types showing transitions between porphyritic and granular structures have been discriminated. Rims showing a similar diversity surround about 10% of chondrules. The composition and structure of the chondrules suggest a source from the nebular dust disk around the Sun. The abudance of voids and their relatively large size and a lack of fissures, indicate a small size of the host body, which must have been derived from an early phase of protoplanet formation.