普通球粒陨石的物理和岩石学性质及其分类参数

摘要

不同球粒陨石群的物理和岩石学性质,包括球粒的平均大小、球粒结构类型、复合球粒、带火成边球粒及含硫化物的比例、化学组成及矿物学特征等可用以划分球粒陨石的化学-岩石类型和小行星类型,这些性质提供了不同球粒陨石群有用的分类参数及其形成环境的信息.由于不同球粒陨石群的△17O与日心距离存在有相关关系,因此,依据不同球粒陨石群形成时的尘粒量和△17O值随着距太阳距离的增大依次形成:EH-EL、OC(H、L、LL)、R、CR、CV-CK、CM-CO球粒陨石群,并推测早期太阳星云内曾发生过连续的化学分馏作用.%The physical and petrologic properties of the different chondrite groups, including mean size of the chondrules, proportions of the chondrule textural types, proportions of compound chondrule, the proportions of chondrules with igneous rims. and the proportions of chondrules that contain sulfide, chemical compositions and mineral features derived from the early solar nebula are used to classify chemical-petrologic types and asteroids.These properties provided useful taxonomic parameters for different chondrite group (EH, EL, H, L. LL. R, CV,CK. CR, CM, CO) and the information of their formation environment in which chondrules formed. There is correlation between △17O and heliocentric distance for these chondrite groups. Thus, different chondrite groups may be put in the order of EH-EL. OC (H, L, LL), R, CR. CV-CK. CM-CO, with increasing heliocentric formation distance. based on the amount of dust present where they formed and △17O values of different chondrite groups.We infer that continual chemical fractionation occurred in the early solar system.