Space petrology and the planetary evolution of the solar system

This paper shows that ferrous silicate meteorites (chondrites), which are conventionally regarded as direct condensates of the primordial solar nebula, are actually igneous and evolved in two stages that were contrasting in their physical and chemical parameters. The origin and early evolution of chondrites went on under enormous fluid pressure, which produced diamond embryos oversaturated with fluid inclusions, and gave rise to isotope abnormality and chondrite structure due to tear-shaped segregation of silicate melt in a Fe-rich diamond-bearing matrix melt. Chondrite crystallization mostly occurred during the second stage, which occurred under low pressure and was characterized by normal fractionation of isotopes and formation of structure opposite to chondrite (containing metal droplets in a silicate matrix), and which involved the formation of volcanic glass.