Petrological Model for Condensation Process of Solar Nebula:(1) Condensation Genesis of Chondrites
太阳星云凝聚过程的岩石学模型：（1）球粒陨石的凝聚成因

in order to reasonably explain the origin relation between meteorites, Earth and terrestrial planets, to discuss the Earth's source and estimate earth's bulk composition, it is necessary to set up a Petrological model for condensation process of solar nebula in terrestrial planet region. In the paper (1), based on physical and chemical conditions of nebula from the cosmochemistry and evolution theory of solar system and experimental results of condensation Petrology, we infer that gas-solid condensation and gas-liquid-solid condensation of nebula could occur in terrestrial planet region of nebular disk. Through studies on mineral composition and structure of chondrules and matrix, the gas-liquid-solid condensation genesis of chondruls and gas-solid condensation genesis of matrix are proved and condensation genesis model for chemical groups of chondrites is discussed.