早期太阳星云演化历史的指示剂——不同类型陨石母体的吸积和形成过程

INDICATOR OF EVOLUTION HISTORY OF EARLY SOLAR NEBULA——ACCRETION AND FORMATION PROCESS OF DIFFERENT TYPE OF METEORITE PARENT BODY

不同类型球粒陨石母体的形成过程,可作为早期太阳星云化学演化的指示剂,它们包含原始球粒陨石中残存的前太阳颗粒,可提供太阳系外恒星演化的信息;原始球粒陨矿物-岩石学特征,可揭示早期太阳星云的凝聚和吸积作用过程;原始球粒陨石主要组分的氧同位素组成,可为了解形成不同类型球粒陨石的初始物质和形成环境提供重要的依据;原始球粒陨石中富钙-铝包体和球粒的形成年龄,可作为早期太阳星云演化的时标;原始球粒陨石的氧化-还原作用特征,可推断不同类型球粒陨石母体在太阳星云内距日心距离等,并进一步探讨早期太阳星云的化学演化。

The accretion and formation processes of different type of chondrite parent body are referred to as indicators of evolution history of early solar nebula. They include pre-solar grains in primitive chondrites providing information of stellar evolution outside solar system. Mineralogicpetrologic characteristics of primitive chondrites reveal process of condensation and accretion in the early solar nebula. Oxygen isotopic composition of the major components in primitive chondrites may provide strong evidence of precursor materials and formation environment for the chondrites of different types. Formation ages of Ca-Al-rich inclusions and chondrules may speculate the time-scale of evolution of the early solar nebula. The features of oxidation-reduce process of primitive chondrites can be deduced formation location of the primitive chondrites of different types in early solar nebula and distance from the sun. All of these we can propose chemical evolution of early solar nebula.