Preliminary examination of lunar samples. Part A: A petrographic and chemical description of samples from the lunar highlands

Chemical, petrographic, and textural characteristics of a representative collection of the Apollo 16 rock and soil samples are reported. The macroscopic and microscopic texture are the result of two or more events in the history of any given sample. Cataclastic, highly crushed rocks are common along with complex intergrowths of shock-produced glass, devitrified glass, and pre-existing clasts. The dominant chemical feature is the high abundance of aluminum and calcium. In terms of their petrogenesis, the rocks are typed as cataclastically, and cataclysmically modified anorthosites; igneous; and polymict breccias.