Grain‐size Distribution and Morphology of Metal in E‐chondrites

The size distribution and morphology of metal grains have been examined in 11 sections of types I and II E‐chondrites. The changes in the grain‐size distribution and morphology of metal grains correspond with the petrologic types and define a series that reflects increase in thermal metamorphism in the following order: type I, Kota Kota‐Indarch‐South Oman‐St. Mark's; and type II, Jajh deh Kot Lalu‐Atlanta‐Daniel's Kuil‐Hvittis‐Pillistfer‐Khairpur‐Blithfield. Concentrations of metal grains adjacent to the perimeters of chondrules are observable throughout the sequence and delineate relic chondritic structure in six of the seven type II E‐chondrites; relic structures are absent from Blithfield.