Meteorites and the Early History of the Solar System

The early thermal history of meteoritic matter is discussed. Clues obtained from the mineralogy of the carbonaceous chondrites are described. An attempt was made to establish the origin of the high-temperature minerals that served as the starting material for carbonaceous chondrites and the possible settings for the aqueous stage of the minerals. The occurrence of primordial noble gases in the meteorities is discussed. Chemical fractionations in the chondrites, extinct radioactivity, and general isotopic anomalies are also discussed. A series of possible events in the history of the solar system, based on the conditions discussed, is presented. (M.C.G.