Local and exotic components of primitive meteorites, and their origin

The chemical and isotopic compositions of chondrites and their implications for chondrite origins are considered, reviewing the results of recent theoretical and experimental investigations. Numerical data are compiled in tables and graphs and discussed in detail. Consideration is given to the properties and classifications of chondrites; components of local origin in the matrix, chondrules, Ca-Al-rich inclusions, and carbon and organic matter; exotic components such as O-16-enriched dust, nucleosynthetic anomalies, and extinct radionuclides; and isotopic anomalies of volatiles such as C, N, and the noble gases. The implications of the chondrite data for the stony fraction of comet nuclei are briefly indicated.